©2001 iBiquity Digital Corporation

Report to the National Radio Systems Committee

FM IBOC DAB Laboratory and Field Testing

August 2001

iBiquity Digital Corporation

8865 Stanford Boulevard, Suite 202 Columbia, Maryland 21045 (410) 872-1530

20 Independence Boulevard Warren, New Jersey 07059 (908) 580-7000

Executive Summary iBiquity Digital Corporation’s report to the National Radio Systems Committee details results of laboratory and field tests of its FM IBOC DAB system. These test results demonstrate conclusively that iBiquity’s system represents a significant improvement over existing analog service and that IBOC can be introduced without meaningful interference to existing analog operations. The information in this report supports the conclusion that IBOC meets the needs of the broadcast industry, the consumer electronics industry and the listening public. iBiquity encourages the NRSC to promptly endorse the IBOC DAB system to encourage the rapid commercial rollout of digital radio next year. The test program summarized in this report was conducted in accordance with the NRSC’s IBOC DAB test procedures. The tests included both laboratory and field tests designed to assess the performance of the digital system and to determine whether digital implementation would impact existing analog operations. Objective laboratory tests were conducted by the Advanced Television Testing Center. Field tests were conducted by iBiquity personnel in the presence of NRSC observers. Audio samples from the field and the laboratory were subjectively evaluated at Dynastat Laboratories. Additionally, iBiquity has completed detailed station, market and listener analyses and extensive field trials to quantify the potential real world impact of digital interference on the existing FM broadcast infrastructure. The performance test results provide an overwhelming endorsement of the benefits of IBOC. For every evaluation criteria the NRSC has adopted, IBOC’s performance is superior to or, at a minimum, equivalent to analog. Similarly, the overall compatibility results confirm IBOC will not degrade analog performance. An overview of iBiquity’s results addressing the evaluation criteria is outlined below.

Audio Quality The performance tests establish the superiority of IBOC audio quality when compared to analog. In performance tests involving 600 sound samples and 120 listeners, evaluators overwhelming and consistently scored IBOC superior to analog. This superiority of IBOC performance applies in all tested genres including classical, country, rock, speech, and voiceovers. Moreover, these test results were obtained in all significant test conditions such as multipath interference, first adjacent, second adjacent and dual interferers, noise and impairments. iBiquity believes these results were based on the improved audio quality of the IBOC system and the system’s ability to improve the overall listening experience.

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Service Area Field tests conducted on eight FM stations representing all station classes and conditions demonstrated the extensive service area IBOC provides. Even at 1/100 of the power of analog, IBOC provided high quality audio throughout the existing market. Overall, digital coverage consistently extended to at least the 45-50 dBu signal level. In several cases, digital coverage extended well beyond this to the 15-25 dBu signal level. In all cases, the system’s blend-to-analog feature ensured that coverage was never less than existing analog coverage. The test results show this level of digital coverage with first adjacent and second adjacent channel interference, multipath terrain obstructions, multiple classes of stations and various antenna configurations. The field tests demonstrated flawless digital coverage throughout Manhattan where multipath significantly degrades analog reception. In San Francisco, the test results show the digital system’s extensive coverage in one of the most challenging environments for analog FM. Moreover, the system has shown its ability to withstand extreme levels of adjacent channel interference. In field tests conducted on WHFS, the IBOC sytem delivered digital coverage with second adjacent interference of –65 dBu D/U.

Durability IBOC also exhibited superior robustness in the face of interference and channel impairments. Subjective evaluations of audio samples from digital and analog auto receivers resulted in consistently higher scores for digital performance with first adjacent channel interference, second adjacent channel interference and multipath. Throughout these tests, digital performance remained consistently strong even as impairments increase. This contrasts with analog performance, which degrades progressively as impairments become more severe. The introduction of digital will increase resistance to interference and transform areas of unacceptable analog performance into areas with excellent digital quality. iBiquity designed an additional robustness test, the “Ticker Test,” which was used to evaluate impairments on audio samples for both digital and analog receivers. Evaluators found that the analog samples had 4-5 times more impairments than digital. Even more importantly, participants reported hearing 6-7 times more severe analog impairments than digital. The listeners’ subjective evaluation scores also demonstrated that the quality of the audio was directly related to the number of impairments. Therefore, IBOC’s elimination of impairments resulted in a marked improvement in digital quality and digital durability.

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Host Compatibility The test program confirmed the IBOC system caused no harm to the analog operations of the host station. The newly introduced digital signal did not degrade the analog operation of the same station. An analysis of the subjective evaluation of audio samples with IBOC turned off and on indicated listeners did not perceive any meaningful difference from the introduction of IBOC.

First Adjacent Compatibility

Examining the full test record leads to a definitive conclusion: the introduction of IBOC will have no meaningful impact on FM analog broadcasting from increased first adjacent interference. Although field test results indicate some potential impact on analog first adjacents, further analysis of the real world situation demonstrates that the incidence of this potential impact is not meaningful. Detailed analysis of every FM station across the country shows that the actual coverage area potentially impacted by IBOC first adjacent interference is very small. Further, analysis of existing listening patterns demonstrates that within the limited area potentially affected, the number of existing listeners is exceedingly small. On average, only 0.6% of an FM station’s existing analog listeners will experience any impact from the introduction of IBOC. This analysis is supported by iBiquity’s extensive field trial record. Over the past 24 months of on-air trials, iBiquity has broadcast IBOC on commercial stations in some of the nation’s most interference intensive markets without any reported impact to the analog broadcasts.

Second Adjacent Compatibility Results of second adjacent compatibility tests mirror the host compatibility results. Again, evaluators indicated no meaningful difference in the analog signal with the digital turned off or on. In the case of portable and home Hi-Fi receivers, the impact of IBOC at stronger interference levels only occurs when analog second adjacent interference has already severely degraded the desired analog signal. At that point, the digital signal’s impact is irrelevant.

… The test results provide a comprehensive view of the benefits of IBOC. The digital system has the potential to offer significant upgrades and benefits without harming analog operations. iBiquity encourages the NRSC promptly to endorse IBOC and move forward to promote industry implementation of digital radio early next year.

TABLE OF CONTENTS

Executive Summary ............................................................................................................. i Audio Quality................................................................................................................... i Service Area.................................................................................................................... ii Durability ........................................................................................................................ ii Host Compatibility......................................................................................................... iii First Adjacent Compatibility.......................................................................................... iii Second Adjacent Compatibility ..................................................................................... iii

I. Introduction ..................................................................................................................... 2 A. Background on iBiquity and IBOC Technology........................................................ 2 B. The NRSC Test Program............................................................................................ 2 C. Subjective Component of NRSC Test Program......................................................... 5 D. Value of Field Test Results........................................................................................ 6 E. The Test Report .......................................................................................................... 7

II. Results ............................................................................................................................ 8 A. Audio Quality............................................................................................................. 8 B. Service Area ............................................................................................................... 9

1. Overall Coverage .............................................................................................. 10 2. Coverage with First Adjacent Channel Analog Interference............................ 12 3. Coverage with Second Adjacent Channel Analog Interference ....................... 13 4. Coverage with Second Adjacent Channel Digital Interference ........................ 15 5. Coverage with Dual Second Adjacent Channel Analog Interferers ................. 15 6. Coverage with Multipath .................................................................................. 17 7. Coverage for a Class A Facility ........................................................................ 21 8. Coverage with Multiple Antenna Configurations............................................. 22 9. Coverage with Terrain Obstructions................................................................. 22

C. Durability ................................................................................................................. 27 1. Subjective Evaluation of Field Audio Samples ................................................ 28 2. Ticker Test ........................................................................................................ 32

D. Acquisition Performance.......................................................................................... 35 E. Auxiliary Data Capacity ........................................................................................... 35

Hybrid ............................................................................................................................... 36 Extended Hybrid ............................................................................................................... 36 All Digital ......................................................................................................................... 36

F. Behavior as Signal Degrades .................................................................................... 37 G. Stereo Separation ..................................................................................................... 38 H. Flexibility ................................................................................................................. 39 I. Host Compatibility .................................................................................................... 39 J. Non-Host Compatibility ............................................................................................ 40

1. First Adjacent Compatibility............................................................................. 40 2. Second Adjacent Compatibility ........................................................................ 53

III. Conclusions................................................................................................................. 55

This report to the National Radio Systems Committee (“NRSC”) details the results of laboratory and field tests of iBiquity Digital Corporation’s (“iBiquity”) FM IBOC DAB system. During the past seven months, iBiquity’s system has undergone comprehensive tests carried out pursuant to laboratory and field test procedures the NRSC developed. The results described in this report demonstrate that the iBiquity™ FM IBOC DAB system represents a significant improvement over existing analog service and that IBOC can be introduced without meaningful interference to existing analog operations. iBiquity has demonstrated through this test program, carried out by independent third parties, that its system can provide robust digital performance throughout the market served by today’s analog stations. The tests also show the iBiquity system eliminates virtually all of the impairments that degrade existing analog broadcasting and, at the same time, demonstrate that the system offers higher audio fidelity. These improvements can be introduced without meaningful interference to existing analog stations. The information in this report supports the conclusion that IBOC meets the needs of the broadcast industry, the consumer electronics industry and the listening public and should be implemented in the United States. iBiquity encourages the NRSC to endorse iBiquity’s IBOC DAB system, to provide a written endorsement of IBOC to the Federal Communications Commission and to promote the rapid commercial rollout of digital radio to meet the needs of listeners, broadcasters and the consumer electronics industry. I. Introduction

A. Background on iBiquity and IBOC Technology iBiquity was formed in August 2000 through the merger of Lucent Digital Radio and USA Digital Radio. iBiquity is the world’s leading developer of digital technology for terrestrial radio broadcasting and is at the forefront of innovation and development in the field of audio compression. iBiquity is owned by a broad coalition of broadcasters, transmitter, semiconductor and receiver manufacturers and leading financial institutions that have come together to support the transition of AM and FM radio from analog to digital. Among iBiquity’s broadcast owners are fourteen of the nation’s top twenty radio broadcasters, including the eight largest. Together, these companies operate more than 2300 radio stations in the United States in over 239 of the 283 Arbitron-rated markets. iBiquity’s owners have access to over 220 million listeners and account for 57% of the broadcast industry’s annual revenues. iBiquity’s owners also include the nation’s largest transmitter manufacturer and second largest radio receiver manufacturer. Additional information about iBiquity can be found at its web site: www.ibiquity.com iBiquity and its predecessors pioneered the development of digital technology for terrestrial AM and FM broadcasting. The iBiquity technology focuses on a digital solution that works within the existing broadcasting infrastructure and also provides key benefits for broadcasters, consumers, equipment manufacturers and regulators. This system places the digital signal within the existing spectral emissions mask for analog AM and FM broadcasts. As a result, IBOC will be introduced without the need for new frequency allocations and without disruption to the existing broadcasting infrastructure.

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Broadcasters will be able to use their existing transmission facilities and studio equipment with only the addition of an IBOC exciter and, in limited cases, an upgrade to the station transmitter. Moreover, IBOC has the important advantage of offering all broadcasters the ability to upgrade to digital. The IBOC approach also benefits consumers by permitting the provision of digital service without changes in consumer behavior. They will continue to tune to the same dial position to find their favorite stations. Finally, IBOC will allow regulators to authorize the introduction of DAB without the need to identify new spectrum or issue new licenses. Overall, the result will be much more prompt introduction of service than could be achieved with a non-IBOC approach. IBOC technology offers the public an improved listening experience and allows broadcasters to offer new services to listeners. IBOC provides improved audio fidelity and enhanced robustness to the broadcast signal, even in the presence of impairments and interference. Additionally, IBOC permits the introduction of new data services to consumers to complement existing audio programming. iBiquity has structured its system to maximize the benefits to consumers within the constraint imposed by the need to protect existing analog AM and FM services. Importantly, the system has been designed to afford broadcasters considerable flexibility to tailor the system attributes to meet the specific needs of listeners in particular markets. The iBiquity FM system presented in this report is based on the LDR and USADR systems that were tested in 1999 and evaluated by the NRSC in 2000. The general system characteristics and attributes are well known by the NRSC. Due to marketplace demands for rapid testing and implementation of IBOC and equipment constraints, the system tested and presented in this report used AAC as audio compression technology. iBiquity will use iBiquity’s audio compression technology in commercial IBOC equipment. This substitution of the system codec will not impact any of the test results presented in this report. It also is important to note that the results presented in this report, conducted with first generation equipment, represent a baseline for IBOC performance. Any subsequent changes in the system will be incorporated only to the extent that they improve system performance. Additionally, iBiquity anticipates commercial grade equipment will exhibit even better performance than the results presented herein. A detailed description of the system tested can be found in Appendix A. All results presented in this report were derived from operation of the IBOC system in the Hybrid waveform mode. No tests were performed using the Extended Hybrid or All Digital modes.

B. The NRSC Test Program On August 14, 2000, the NRSC released a Request for Proposals offering all interested parties with functional IBOC DAB systems an opportunity to participate in the NRSC’s standards development process. iBiquity is the only company that responded to the NRSC Request for Proposals. At the end of 2000, the NRSC developed comprehensive FM IBOC laboratory and field test procedures focused on two areas. First, the test procedures were designed to assess the performance of the iBiquity system

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(i) in a clean channel environment, (ii) with various forms of impairments, (iii) with co- and adjacent channel interference, and (iv) with multipath interference. Second, the test procedures were designed to address the system’s compatibility with existing analog operations by looking at any impact on host channel analog operations as well as analog first and second adjacent channel stations. Based on its analysis of market information, the NRSC selected the following four analog receivers for testing, representing commercially available and commonly used receivers in the most important market segments. These receivers also were selected for their ability to provide some of the best

Type Manufacturer Model No. Original Equipment Auto Delphi PN 09394139 Aftermarket Auto Pioneer KEH-1900 Home Hi-Fi Technics SA-EX140 Portable Sony CFD-S22

Table 1 – List of Test Receivers

performance in their respective market segment. All four receivers were used for both performance and compatibility testing. In the performance tests, recordings were made of the digital and analog receivers. The analog receivers were used to provide an analog reference for comparison with digital performance. In compatibility testing, only the analog receivers were used. These tests were designed to compare the quality of the analog receiver with IBOC turned off and on. This comparison was meant to assist the NRSC to assess any impact of digital transmissions on the analog signal. All objective laboratory tests were conducted at the Advanced Television Technology Center, Inc. (“ATTC”) in Alexandria, Virginia using the IBOC DAB test bed established for the iBiquity system. ATTC is a private, non-profit corporation organized by the broadcast and consumer products industries to test digital broadcast systems. Appendix B contains a schematic of the ATTC test bed. The NRSC and its observers were afforded open access to the ATTC test bed at all times, and an NRSC representative actively participated in the lab’s work. The ATTC recorded all data from these tests. Appendix C contains a report describing the procedures followed at the ATTC. The laboratory tests produced a series of objective measurements that are summarized in the ATTC’s report contained in Appendix D. In addition to these objective measurements, the ATTC recorded audio samples for both the digital and analog receivers for each test conducted. The audio samples were subsequently sent to Dynastat, Inc. in Austin, Texas for subjective evaluation. Dynastat’s laboratory has been conducting high quality subjective evaluations of audio and speech technology for more than 27 years. Again, Dynastat’s laboratory was open to the NRSC, and an NRSC observer validated the procedures used at Dynastat. Appendix G contains a thorough explanation of the rationale for the subjective evaluation program and an overview of the procedures used for selection and handling of the audio samples subjectively evaluated. Appendix H contains a detailed description of the methodology and specific procedures used at Dynastat. Appendix I details the results of the subjective evaluation.

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Field testing comprised the final component of the test program. The NRSC’s field test procedures identified specific conditions to be tested, the test stations to be used and the drive routes to be followed. These field tests were conducted at several commercial and one experimental FM radio station. All tests were conducted using iBiquity personnel and equipment. The majority of the field tests were conducted in the presence of an independent auditor supplied by the ATTC. An NRSC observer witnessed all field tests. Appendix E contains a detailed description of the field test equipment, the set up in the mobile van used to record measurements and the overall parameters of the field testing. The field test stations are listed below.

Station Location Frequency Class Analog

Power Digital Power

HAAT

WETA Washington, DC

90.9 MHz B 75kW 750W 185m

WHFS Annapolis, MD

99.1 MHz B 50kW 500W 142m

WPOC Baltimore, MD

93.1 MHz B 16kW 160W 269m

WNEW New York, NY

102.7 MHz B 6kW 60W 413m

WWIN Baltimore, MD

95.9 MHz A 3kW 30W 95m

KWNR Las Vegas, NV

95.5 MHz C 92kW 920W 351m

KLLC San Francisco, CA

97.3 MHz B 82kW 820W 315m

WD2XAB Columbia, MD

93.5 MHz N/A 800W 8W 15m

Table 2 - Field Test Stations

Appendix F contains the objective field test results in the form of maps and charts. For each test station, iBiquity has supplied a map depicting the digital coverage on all radials driven, a map of the digital coverage plotted against the Longley-Rice predicted signal level for the station,1 and strip charts for each radial. The strip charts contain additional details about the strength of adjacent channel interferers, distance from the transmitter and whether the digital receiver was operating in digital or analog mode. In addition, Appendix F contains terrain elevation information for each test station. Audio samples from the field tests were selected for further evaluation based on the NRSC’s criteria for characteristics to be assessed from the field tests. These audio samples were sent to Dynastat for subjective evaluation and were used as the basis for 1 Because WD2XAB is not a commercial station, no predicted coverage map has been included for this

station.

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developing Mean Opinion Scores for digital performance and for an additional test of durability (“Ticker” Test) described in Appendix K. An NRSC observer inspected the methodology and procedures and set up for selection of audio samples from the field tests and certified that the process conformed to the NRSC’s standards.

C. Subjective Component of NRSC Test Program

There are numerous ways to measure and characterize audio system performance, including objective measurement, subjective evaluation and expert listener assessment. It is widely accepted that subjective assessment plays a critical role in effectively characterizing transmission devices, audio compression, codecs and other non-linear DSP based techniques.2 For the last fifteen years, subjective evaluation has been considered “the gold standard of audio system evaluation”3 in both the telecommunications and audio industries. As is evident from a vast number of ITU-R standards,4 the audio and codec communities have embraced methodologies that rely on subjective evaluation to assess the audio quality of new products. Thus, although the objective results from the laboratory and field tests provide interesting data, iBiquity believes that subjective evaluation results provide the best means to assess the true significance of a system’s performance. In particular, subjective evaluation using general population participants allows the NRSC to understand customer acceptance of IBOC in a variety of real-world listening conditions. This should provide the best insight into the value of IBOC as an upgrade to analog radio as well as the most meaningful assessment of whether IBOC will have a meaningful impact on existing analog operations.

In order to subjectively assess the audio quality of a system it is critical to choose a test methodology that predicts real-world behavior of consumers in real-world environments. When the experimental task closely matches the experience that people will actually encounter, the experiment will inevitably produce the most accurate prediction of customer acceptability. With this in mind, the NRSC approved a large-scale subjective test program for the purpose of evaluating the IBOC system. Subjective experiments were conducted for all major areas included in the NRSC test plan, including hybrid performance, compatibility, main channel and subcarrier transmissions. iBiquity developed an additional experiment to assess durability in core coverage areas (Ticker Test), and an experiment was conducted to help interpret results from the subjective evaluations (Interpretation of MOS, found in Appendix J). Approximately 480 people 2 Thorpe, L.A. & Shelton, B. R. (1993) Subjective Test Methodology: MOS vs DMOS in Evaluation of

Speech Coding Algorithms. Proceedings of the IEEE Speech Coding Workshop, St. Agathe, Quebec, Sept. 1993; Thorpe, L.A. (2000) Subjective Evaluation of Speech Compression Codecs and other Non-linear Voice-path Devices for Telephony Applications (ms. under review).

3 Pickholtz, R. L., Jackson, C. L. (1999) A Review of Four Studies of FM Receiver Adjacent-Channel

Immunity (review submitted to the NAB). 4 Methods for the Subjective Assessment of Small Impairments in Audio Systems Including

Multichannel Sound Systems, ITU-R Recommendation BS.1116, Geneva; Subjective Assessment of Sound Quality, ITU-R Recommendation 562-3, Geneva; Methods for the Subjective Assessment of Sound Quality, ITU-R BS.1284, Geneva; Methods for Subjective Determination of Transmission Quality, ITU-T P.800, Geneva.

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with diverse demographic backgrounds participated in the subjective evaluation program. Results from each experiment represent data from 40 participants, stratified by both gender and age.

The chosen subjective test methodology, the Absolute Category Rating Mean Opinion Score (ACRM), has been used in a variety of circumstances to test customer opinion of telecommunications and audio products entering the marketplace.5 This methodology was chosen because it best tests customer preference and market acceptability. In the ACR methodology, subjects judge the sound samples they hear on an individual basis. For each sample, they use their internal frame of reference to judge the audio quality. Participants subjectively evaluate audio samples based on five categories: Excellent; Good; Fair; Poor; Bad. Answers from the participants are later translated into numerical values (5 through 1) for the purpose of computing mean opinion scores from individual scores. In each ACR experiment, participants were presented with approximately 200 sound samples that differed on several dimensions. They were asked to give a statement of “overall quality” for each sample, taking into consideration the variety of audio dimensions or impairments that were present. Before starting the experiment, participants were familiarized with the range of impairments they would encounter. The subjective evaluation lab screened participants for their ability to hear small impairments and/or differences in audio quality. Only responses from participants who were trained and who passed the screening test were included in the data that is presented in this report.6

The MOS Interpretation Study was conducted for the purpose of providing

context for scores derived from ACR experiments. This study identified the point at which an average listner would no longer listen to a radio signal. This point was slightly different for each genre: 2.0 for Rock; 2.1 for Classical Music, and a 2.3 for speech. When interpreting subjective evaluation results this average “turn’off” point should be considered as one measure of consumer acceptability.

D. Value of Field Test Results A review of the laboratory and field test results reveals that field tests are much more predictive of actual IBOC system performance than laboratory test results. For a variety of reasons, the laboratory tests were limited by the constraints of the laboratory environment and provided inaccurate reflections of the performance of both analog and digital audio broadcasting.

As is apparent in this test program, in both the performance and compatibility tests, the lab exaggerated the most extreme results. In the performance tests, this produced unrealistically low evaluations of analog quality. Table 3 below shows two examples of this effect, taken from performance test data. The first example,

5 The ACRM is documented in the ITU-T P.800 standard, Methods for Subjective Determination of

Transmission Quality. 6 See Appendices G & H for a detailed description of ACRM.

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Performance With First Adjacent Channel Interference, is the most extreme case in which field and lab data diverge. The second case, Performance With First Adjacent Channel Interference And With Multipath, is more typical. Both cases, however, demonstrate that lab tests bias results. Obviously, in these cases, the analog radios received unrealistically low scores. In compatibility tests, the opposite happens, leading to unrealistic concern about analog susceptibility to digital impact. There are several reasons why field tests are more reliable indicators of both IBOC and analog performance

1St Adjacent Interference 1St Adjacent w/ Multipath Field Lab Field Lab

IBOC 4.5 4.6 4.3 4.0 Delphi 4.0 1.0 3.0 2.2 Pioneer 4.0 1.0 2.6 2.4

Table 3 - Example of Exaggerated Lab Test Results

than laboratory tests. First, experiments that use commercially broadcast material transmitted over actual commercial systems most closely mimics the real world. In contrast, audio generated in the laboratory environment sounds more artificial to listeners. This stems from the fact that field audio samples are more complex, mixing a range of real-world impairments into the audio segments. However, laboratory samples are created by mixing one or more specific impairments with a clean channel signal. The result is often a laboratory sample that overly emphasizes the impairment. The most obvious example of this is in the area of multipath. Second, field tests offer a wider range of test conditions (more critical D/U ratios, larger range of programmatic material) than lab tests. Finally, a great percentage of lab tests were designed to explore extreme conditions and system limits rather than more common listening experiences. Again, these extremes apparently affected listeners’ ratings negatively, as is reflected in the harsher evaluations they gave to both analog and digital systems at various points in the laboratory program.

E. The Test Report This test report consists of a main text analyzing each of the NRSC evaluation criteria and the iBiquity system’s ability to satisfy each of the criteria. In addition, the report includes a series of appendices, which contain greater detail about the system design, the test procedures and methodology, and the test results. iBiquity completed 100% of the tests outlined in both the laboratory and field test procedures. iBiquity performed additional tests, such as the Ticker Test and the MOS Interpretation Test, as

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well as detailed station, market and listener analyses to qualify the results presented in this report a more complete understanding of the IBOC system. This report presents (i) all the results from the laboratory and field performance tests and (ii) laboratory and field compatibility tests for main channel audio. Lab and field compatibility tests involving SCA operations will be presented at a later date. II. Results

A. Audio Quality7 The performance tests, taken in their entirety, establish conclusively the superiority of the audio quality of the iBiquity system over existing analog FM. In subjective evaluations of all the performance tests, evaluators overwhelmingly and consistently scored digital superior to analog. Performance sound samples were selected from seven of the eight FM test stations providing a strong cross section of formats and conditions.8 These samples comprised three full tests at Dynastat and involved 120 listeners evaluating over 600 sound samples. As Figure 1 below illustrates, digital consistently outperformed analog. Figure 1 aggregates the performance of the IBOC, Delphi and Pioneer receivers in all conditions. This includes first adjacent, second adjacent and dual adjacent interference, noise, multipath and channel impairments. In each genre tested, digital was judged to be superior to analog.

7 The IBOC DAB equipment used in the tests incorporated the AAC audio compression technology

rather than the iBiquity audio compression technology that the final system will use. The codec used in the test equipment has no impact on the NRSC’s ability to assess the compatibility of the system with existing analog operations or the performance of the system in the face of impairments and interference. However, the NRSC agreed that the unimpaired audio quality test, which looks at audio fidelity in a clean channel environment, is designed to assess the performance of the codec and would be inappropriate to conduct until iBiquity’s compression technology is incorporated in the system. Therefore, no data related to unimpaired audio quality is available from this test program.

8 Field testing of WWIN was completed after the performance audio samples had been sent for

subjective evaluation.

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1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

Digital 4.6 4.2 3.9 4.5 3.9

OEM Analog 3.2 3.4 3.0 3.1 2.9

After Market 3.2 3.0 2.7 2.8 2.6

Classical Country Rock Speech Voiceover

Figure 1 - Performance of Digital and Analog Receivers

Aggregating All Field Test Conditions

Although these performance tests also assessed the durability of the system, iBiquity believes that listener evaluations were based on the superior audio quality of the digital signal, the system’s enhanced ability to overcome impairments and the improved quality of the overall listening experience. The first and third of these factors relate to overall audio quality. iBiquity believes these perceptions of greatly enhanced audio quality can be attributed to two benefits of the iBiquity system. IBOC is able to deliver higher audio fidelity that approaches compact-disc quality. At the same time, many of the innovative technologies incorporated in the system have been designed to reduce or eliminate the noticeable impairments that frequently degrade the listening experience of analog FM. The elimination or reduction of effects from multipath interference, the reduction in the system’s susceptibility to noise and other impairments and the interference reducing techniques incorporated in the system all reduce the audible pops and clicks that have impaired the analog FM listening experience. The success of iBiquity’s efforts to enhance the listening experience and improve audio quality is borne out by the subjective evaluation results.

B. Service Area Field tests using eight stations demonstrated that the IBOC system provided an extensive digital service area in all environments typically encountered in FM broadcasting. Even at 1/100 of the power of analog, IBOC provides high quality audio throughout the existing market. Field test environments emphasized (i) first and second adjacent channel interference, (ii) severe specular and diffuse multipath, (iii) urban, suburban and rural conditions, and (iv) terrain obstructions. Field test stations included

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all classes of FM stations with one Class A station, five Class B stations and one Class C station. In all cases, digital coverage extended to approximately the 45-50 dBu signal level. In several cases, digital coverage extended well beyond this point to the 15-25 dBu signal level. Although the differing characteristics of the field test stations make it difficult to generalize about the digital service area, the results indicate the IBOC system offers digital coverage meeting or exceeding each station’s protected analog coverage area. In all cases, the system’s blend-to-analog feature ensures that coverage was never less than existing analog coverage. The field test stations incorporated in the NRSC test procedures were selected to assess system performance in the most common FM environments. Table 4 below contains a list of the relevant broadcast environments included in the field test program and which stations were used to assess each environment

Characteristic Assessed Station 1. Overall Coverage -- Performance in an area

characterized by low interference WETA

2. 1st Adjacent Channel Interference WPOC, WNEW 3. 2nd Adjacent Analog Interference WNEW, KLLC 4. 2nd Adjacent Digital Interference WD2XAB 5. Dual 2nd Adjacent Channel Analog

Interference WHFS

6. Multipath WNEW, KLLC, KWNR, WHFS

7. Class A Facility WWIN 8. Centrally Located Urban Antenna WNEW 9. Terrain Obstructions KLLC, KWNR 10. Low Level Power Combining WWIN

Table 4 - Field Test Stations and Characteristics Assessed During Tests

1. Overall Coverage

WETA provides one of the best examples of the overall coverage of the digital

system. WETA has no strong first or second adjacent channel interferer and does not have significant terrain obstructions, except in the western part of its service area. Because WETA is located in a congested, urban market, multipath interference impacts coverage and service quality for analog reception. Even so, with an antenna height of 186 meters HAAT and analog power of 75 kW, WETA enjoys extensive analog coverage. The field performance tests demonstrate extensive digital coverage on WETA as well. As Figure 2 illustrates, on all radials, the system delivered consistent digital coverage to approximately the 35 dBu signal level.

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Figure 2 -WETA All Radials with Analog Field Intensity

A more detailed analysis of the western radials for WETA reinforces the conclusion that WETA has extensive digital coverage. Figure 3 provides a more detailed presentation of the WETA analog field intensity for the 270° and 315° radials. As Figure 3 highlights, the first blends on these radials occurred at approximately 35 dBu. However, even after the initial blends, digital reception continued into areas of 5-10 dBu signal level. In both these cases, this impressive digital coverage occurred even after terrain related blockages caused initial blends to analog. It is important to note analog quality is degraded at the points where digital blends.9

9 See Appendix F.1, page 11 for an illustration of the terrain elevations on these radials.

MODE

Digital

Analog

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Figure 3 -WETA 270° and 315° Radial with Analog Field Intensity Although many other stations experience greater limitations on their analog coverage due to significant interference or other impairments, iBiquity believes the WETA coverage illustrates the potential for extensive digital coverage on the numerous analog stations which currently enjoy large analog coverage.

2. Coverage with First Adjacent Channel Analog Interference

Tests conducted on both WPOC and WNEW demonstrated first adjacent channel interference did not impact digital coverage. Both stations have first adjacent interferers that were assessed in the field test program. Table 5 below lists the adjacent channel interferers for each station.

MODE

Digital

Analog

NOTE First blend occurs at ≈ 35 dBu

NOTE First blend occurs at ≈ 35 dBu

WETA Tx

WETA Longley-Rice Field Intensity (dBu)

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Desired Station Interferer Call Sign Location Channel

Class Call Sign Location Channel

Class Distance

Between Stations

Baltimore, MD

WFLS Fredericks-berg, VA

93.3 B 123 km WPOC

93.1 B

WMMR Phila-delphia, PA

93.3 B 155 km

WNEW New York, NY

102.7 B WMGK Phila-delphia, PA

102.9 B 132 km

Table 5 - First Adjacent Interferers

In both cases, the digital coverage was consistent and extensive. Even in the presence of first adjacent channel interference, digital coverage for each station extended to the 35-38 dBu signal level.10

3. Coverage with Second Adjacent Channel Analog Interference

Tests conducted using WNEW demonstrated the strength of digital coverage even in the presence of strong second adjacent channel analog interference. WNEW has a lower second adjacent channel station, WBAB-FM, operating at 102.3 MHz in Babylon, New York. Figure 4 below illustrates the WNEW 90° radial plotted against the WBAB differential field intensity. This shows the D/U ratio for WBAB’s interference to WNEW. As can be seen in Figure 4, the 90° radial for WNEW passed directly by the WBAB transmitter. Nonetheless, the system continued to deliver digital coverage. Figure 4 shows that digital coverage extended to the 100 dBu contour for WBAB. At that point, the system was experiencing a D/U ratio of approximately -47 dB.

10 See Appendix F.2 at page 1 for more details on the WPOC service area and Appendix F.4 at page 1 for

more details on the WNEW service area.

14

Figure 4 – WNEW 90° Radial with WBAB Field Intensity iBiquity does not expect that all second adjacent channel interference levels will reach this extreme. Nonetheless, this radial was selected to demonstrate the extensive service offerings made possible by the IBOC system even with the existence of very severe levels of second adjacent channel interference. Similar results were obtained with second adjacent channel interference in the San Francisco market. On the South Loop for KLLC, the radial passed within a few kilometers of the KFFG-FM transmitter. KFFG is an upper second adjacent channel interferer operating at 97.7 MHz. Figure 5 shows the IBOC coverage plotted against the D/U ratios for KFFG’s interference to KLLC. As Figure 5 illustrates, the IBOC system offered primarily digital coverage within the 80 dBu contour of KFFG.

MODE

Digital

Analog

Blend Point @ WBAB 100 dBu Contour (F50-50)

WBAB 120 dBu Contour

(F50-50)

WNEW Longley Rice Predicted Differential File Intensity – WNEW / WBAB (dB)

WNEW Tx

15

Figure 5 - KLLC South Loop with KFFG Field Intensity

4. Coverage with Second Adjacent Channel Digital Interference

WD2XAB was used to demonstrate the IBOC system’s ability to maintain digital coverage with second adjacent channel digital interference. WD2XAB operates at 93.5 MHz, second adjacent to WPOC at 93.1 MHz. For these tests, WD2XAB operated in the hybrid mode at the same time that WPOC was broadcasting a hybrid signal. Because WD2XAB is an experimental station operating at limited power of 800 Watts, its analog coverage is extremely limited. Nonetheless, the tests demonstrated the system’s ability to deliver digital coverage even with high levels of second adjacent channel digital interference. The test results demonstrate the station was able to provide extensive digital coverage to approximately the -15 dB D/U signal ratio.11

5. Coverage with Dual Second Adjacent Channel Analog Interferers

Field tests conducted using WHFS confirmed the system’s ability to withstand strong levels of dual second adjacent channel interference and still deliver digital coverage. WHFS, located in Annapolis, Maryland and operating at 99.1 MHz, has two second adjacent channel interferers operating in the same market. WIHT-FM,

11 See Appendix F.8 for additional details about tests on this station.

KFFG (+2) 80 dBu (F50-50)

Contour

KFFG (+2) 60 dBu (F50-50)

Contour

MODE

Digital

Analog

50 kM to Tx

KLLC Terrain Elevation (Meters)

KFFG Tx

16

Washington, D.C., is an upper second adjacent operating at 99.5 MHz. WMZQ-FM, Washington, D.C., is a lower second adjacent operating at 98.7 MHz. Both second adjacent interferers are located at the western edge of WHFS’ analog coverage area. A detailed examination of the 270° radial illustrates the significant coverage of the digital system. This radial passes within less than 1 km of the transmitter for WMZQ. Even so, the system exhibits only limited blending throughout this area. Significant blends do not occur until past the WMZQ transmitter site where the radial reaches beyond the edge of digital coverage. Figure 6 shows the radial plotted against the WMZQ interference to WHFS. As Figure 6 illustrates, even within the 120 dBu contour of WMZQ, which is approximately 49 km from the WHFS transmitter, WHFS still delivered partial digital coverage. That means the IBOC system was able to perform even with interference levels of -65 dBu D/U.

Figure 6 – WHFS 270° Radial with WMZQ Predicted Analog Interference Figure 7 highlights the loss of digital that occurs in this area. In the majority of cases, digital is lost due to front end overload caused by close proximity to the WMZQ transmitter. At this interference level, the undesired signal saturates the receiver front end eliminating reception of the desired signal. Analog radios experience the same effect in these situations.

WMZQ (-2) 120 dBu Contour Tunnel

WIHT (+2) 120 dBu Contour

MODE

Digital

Analog

WHFS / WMZQ (-2) Differential Field Intensity (dB)

17

Figure 7 – WHFS 270° Radial Selection Adjacent to WMZQ Transmitter This location illustrates one of the most extreme cases of second adjacent interference due to the distance from the WHFS transmitter and the proximity to the second adjacent interferer. Nonetheless, the digital system delivers exceptional performance.

6. Coverage with Multipath Throughout the test program, the digital system provided an outstanding coverage area even in markets characterized by severe multipath. KWNR in Las Vegas, Nevada is located in a market dominated by severe specular multipath. The geography of Las Vegas, situated in a bowl surrounded by mountains, encourages the reflection of FM signals. Even with this severe multipath situation, the digital system provided excellent coverage of the Las Vegas market. In fact, the KWNR results show that terrain, not multipath, set the limit on digital coverage. The Las Vegas tests also included a downtown radial on “The Strip” to maximize the potential for multipath interference. As Figure 8 below illustrates, there was uniform digital coverage throughout this drive.

Blending Due to Overload

MODE

Digital

Analog

46 kM to WHFS Tx

18

Figure 8 – KWNR “Strip” Radial Similar results were obtained in urban markets characterized by specular multipath. In New York, WNEW coverage was uninterrupted by the high levels of multipath typical of Manhattan’s urban canyons. This outstanding digital coverage was obtained in an area well known for severely degraded analog reception. The New York Downtown Loop included lower Manhattan, midtown, and upper Manhattan. This loop has a range of urban conditions including lower Manhattan’s narrow streets lines with skyscrapers, midtown’s wider streets surrounded by dense development and upper Manhattan’s mid-rise development. Figure 9 below shows the absence of blend throughout the loop except for one blend related to a tunnel.

MODE

Digital

Analog

18 kM to Tx

2 4 6 8

Kilometers

19

Figure 9 – WNEW Downtown Loop Street Map Thus, the existence of extreme levels of urban multipath did not impact system performance. Similar results were obtained on KLLC in San Francisco during the KLLC downtown loops. In that case, the system offered consistent digital coverage throughout the downtown area. The gaps between gray areas do not represent loss of digital coverage. These gaps are the result of the sampling rate of the system that records the

MODE

Digital

Analog

WNEW Tx

1 2 3 4 Kilometers

20

relevant data. At this level of resolution, the digital plots do not cover all areas of the map. The blends that are illustrated in Figure 10 were the result of receiver overload in the area close to the Mt. Sutro transmitter site. Analog reception also is severely degraded in these areas.

Figure 10 - KLLC Inner and Outer Downtown Loops In the case of WNEW and KLLC, each station’s transmitter was located at a high height in the urban area being studied. WHFS provided an opportunity to study the digital coverage in the face of urban multipath when the transmission originates from a distant, suburban location. The WHFS transmitter is located outside Annapolis, Maryland in an area roughly equidistant from Washington and Baltimore. On the 270° radial, the test route passed through downtown Washington. As Figure 11 illustrates,

Sutro Tower

Site

Loss of Digital Due to

Receiver Overload

Loss of Digital Due to

Receiver Overload

MODE

Digital

Analog 2 4 Kilometers 6 8

Tunnel

Note: Some GPS position data lost due to building obstruction 7 kM to Tx

21

even though the downtown areas were 30+ km from the WHFS transmitter, the digital system was able to provide consistent digital coverage of the area. Overall these tests demonstrate the IBOC system can provide significant digital service in the presence of multipath with a variety of transmission and antenna configurations.

Figure 11 - WHFS 270° Radial Through Downtown Washington

7. Coverage for a Class A Facility

As with the higher powered stations, the IBOC system provided extensive

coverage for a Class A facility, meeting the protected contour for WWIN. This station presented particularly challenging conditions for testing IBOC performance and may not be representative of typical Class A results. First, the WWIN tower is located at sea level at the edge of Baltimore harbor but the bulk of the service area is at a much higher elevation. Due to the station’s low analog power, the IBOC system is producing only 30 watts of digital energy. Also, WWIN’s service area is completely overlaid by WHUR-FM and WPGC-FM, two second adjacent channel interferers transmitting from Washington, D.C. Also, WSOX-FM, Red Lion, Pennsylvania, is a strong first adjacent interferer with significant overlap of WWIN’s service area. Figure 12 below illustrates the interference environment for WWIN.

MODE

Digital

Analog

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Kilometers

33.5 kM to WHFS Tx

22

Figure 12 – WWIN Radials with First and Second Adjacent Interferers Even with significant interference, extremely low power, and lower elevation, the digital system provided significant digital coverage. iBiquity believes more extensive coverage may be found in Class A stations with less severe interference situations.

8. Coverage with Multiple Antenna Configurations The field tests demonstrated the IBOC system’s ability to offer extensive service areas using all commonly employed FM antenna configurations. On WNEW, the digital system operated with a centrally located multiplexed antenna that carries most of New York’s major FM stations. WWIN offered the opportunity to demonstrate the system’s operation with common amplification whereby both the analog and digital signals were amplified by the same device. WPOC uses a stand-alone directional antenna with a null to minimize the signal level in the Washington, D.C. market. In the other cases, the system operated with stations using stand-alone antennas. It is also important to note that the test program included stations with varying antenna heights and power combinations. WHFS, which holds a conventional Class B authorization, operates at near the authorized height and full authorized power. In contrast, WNEW, also a Class B station, operates at significantly reduced power due to the height of its antenna on the Empire State Building. In all cases, the digital system offered extensive digital coverage and no compatibility issues with the various antenna configurations.

9. Coverage with Terrain Obstructions

MODE

Digital

Analog

WHUR (+2) 54 dBu / F50-50

WPGC (-2) 54 dBu / F50-50

WSOX (+1) 54 dBu / F50-50

WWIN 60 dBu / F50-50

WWIN / WSOX (+1) Desired to Undesired Ratio (dBu)

WSOX Tx

WWIN TxWHUR Tx WPGC Tx

23

Even with terrain obstructions, the IBOC system is able to provide digital coverage comparable to analog coverage. Although terrain elevation challenges can be found in most of the field test markets, San Francisco and Las Vegas presented some of the greatest challenges for digital coverage. Nonetheless, the IBOC coverage for both KLLC and KWNR was comparable to analog coverage.

The San Francisco market represents one of the most challenging environments for FM reception. The complete set of loops run on KLLC provides the most comprehensive overview of the system’s extensive service area in a market characterized by extremes of multipath terrain obstructions. The iBiquity system was able to provide service throughout the bay area, extending to both the northern and southern ends of the bay as well as the mountains east of San Francisco. On the north loop, the system operated without any blends. As was discussed above, even though there were blends on the south loop, this actually highlights the system’s ability to withstand extreme second adjacent interference from KFFG-FM. The two areas of significant blends-to-analog appear in the east and west loops. In both cases, the system provides extensive coverage except in those areas with very severe and direct terrain blockage. In those cases, the terrain also significantly impacts analog reception.

Figure 13 – KLLC All Radials with Analog Field Intensity

MODE

Digital

Analog

KLLC Longley-Rice Predicted Field Intensity (dBu)

KLLC Tx Site

24

Figure 14 - KLLC East Loop Terrain Elevation

The terrain blockages are a limiting factor in the reception of analog FM signals in the San Francisco market. Mountains block the FM signals from San Francisco’s three main FM transmission facilities.12 The mountains located to the east of San Francisco Bay effectively limit FM reception from reaching the eastern and western ends of the market, except for those stations with on-channel boosters. Figure 14 illustrates the terrain limitations and shows the location and coverage of the KLLC booster, KLLC-1. Those areas of blended analog service shown in Figure 14 are effectively the signal from KLLC-1. The analog booster was providing analog coverage but the IBOC system did not have the benefit of a digital booster to provide digital service in this area.

Along the west loop, shown in Figure 15, mountains severely limit analog

reception however no analog boosters are employed. Thus, in this area, analog remains degraded.

With the difficult reception problems in the San Francisco Bay area IBOC brings

the possibility to offer what is not possible now, seamless coverage of the market through the use of a limited number of inexpensive on-channel IBOC boosters.13

12 Mt. Beacon, Mt. Sutro and Mt. Bruno 13 iBiquity’s FM IBOC system was designed to accommodate on-channel digital boosters. IBOC

technology, unlike FM on-channel boosters, can provide service without generating areas of interface.

MODE

Digital

Analog

KLLC-1 (On Channel Booster) 60 dBu (F50-50) Contour

20 kM to Tx

KLLC Terrain Elevation (Meters)

KLLC Tx

KLLC-1 On-Channel Booster Causes Receiver AGC to Attenuate DAB Carriers

25

Figure 15 - KLLC West Loop Terrain Elevation The IBOC system offered similar performance in Las Vegas. Unlike San Francisco, which has a combination of water, mountains, urban and suburban areas, Las Vegas has one urban center surrounded by a ring of mountains. As Figure 16 illustrates, the system delivered extensive coverage throughout the area, even into areas with high terrain elevation.

KFFG (+2) 60 dBu (F50-50)

Contour

MODE

Digital

Analog

20 kM to Tx

KLLC Terrain Elevation (Meters)

26

Figure 16 - KWNR All Radials with Terrain Elevation Figure 17 highlights that the only significant blends were directly attributable to loss of signal due to terrain shielding from the mountains or the descent into the Colorado River basin at Hoover Dam. In this market, the mountains create a barrier that almost completely blocks the analog signal. In particular, there is complete muting of analog as the elevation drops down to the Hoover Dam basin. The loss of the digital signal mirrors the limitations of analog coverage in these areas.

MODE

Digital

Analog

KWNR Tx

KWNR Terrain Elevation (Meters)

27

Figure 17 - KWNR 135° and 270° Radials with Terrain Elevation

C. Durability The digital system exhibits tremendous durability in the face of both interference and channel impairments. Several aspects of the test program highlight this strength of the digital system. First, the coverage maps, some of which are discussed above and the remainder of which are contained in Appendix F, illustrate the digital system’s strong coverage in areas characterized by significant levels of first or second adjacent channel interference, multipath or terrain obstructions. Second, as is discussed in greater detail below, the subjective evaluation of digital and analog audio samples derived from numerous listening environments confirms the durability of the system. Finally, iBiquity conducted an additional test (the “Ticker” test) that demonstrated the digital system eliminates the majority of and the most severe impairments that degrade the analog listening experience. Of particular note from the test results is the observation that digital broadcasting will transform areas where analog is currently unacceptable into areas with excellent digital quality. The IBOC system’s ability to eliminate impairments that substantially degrade the analog listening experience significantly extends radio coverage into new areas.

MODE

Digital

Blend

270° Radial

135° Radial

KWNR Tx

MODE

Digital

Analog

KWNR Terrain Obstruction (Elevation in Meters)

28

1. Subjective Evaluation of Field Audio Samples Audio samples from the field tests were selected to assess the digital and analog performance in a variety of environments including first and second adjacent channel interference and multipath. Subjective evaluators were given analog and digital samples recorded simultaneously from the same point of a particular test radial. Because the field tests were conducted primarily in a mobile mode, only the two automobile receivers were used for these tests. Due to the nature of their designs, it can be expected that the home and portable receivers would have received lower subjective evaluation scores relative to IBOC than those received by the automobile receivers. Throughout the tests, digital consistently scored higher than both analog radios. Moreover, the close tracking of the two analog radios throughout these tests enhances confidence that the subjective evaluation effectively captured the correct performance of the analog receivers. The existence of first adjacent interference had a greater impact on analog radio than digital for both music and speech selections. Overall, Figures 18 and 19 illustrate that the IBOC system received higher scores than analog for both music and speech audio selections with the existence of both weak and moderate first adjacent channel interference.

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

IBOC 4.5 4.5 4.1 4.1

Delphi 4.1 3.8 3.0 2.1

Pioneer 4.1 3.8 2.9 2.0

Weak Moderate Weak Moderate

Music Speech

Figure 18 - Digital and Analog Performance with Weak and

Moderate First Adjacent Interference This test provides several interesting insights into the relative performance of the digital and analog receivers. As the interference level increases, the digital performance stays

29

the same. It can be anticipated that this trend would continue until the loss of digital coverage. Due to its design, the digital system provides consistent digital quality throughout the digital service area. The consistent score for both music and speech as the interference level increases from weak to moderate underlines this important aspect of digital performance. The analog receivers, in contrast, quickly begin to degrade as the interference level increases. With both the Delphi and Pioneer receivers, analog performance degrades as the interference increases, with much more dramatic degradation occurring with speech than with music. In fact, when comparing performance with moderate interference levels and speech selections, the analog receivers degrade to a point where it is unlikely that listeners will continue to stay tuned to the radio. The introduction of digital will increase resistance to interference and transform these areas with unacceptable analog performance into areas with excellent digital quality. Similar benefits of the digital system can be found by examining the relative performance of the digital and analog receivers with second adjacent channel interference. As Figures 19 and 20 illustrate, with both music and speech selections, the digital system offers superior performance when compared to analog.

Figure 19 - Digital and Analog Performance with Dual Second Adjacent Channel Interferers - Music

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

IBOC 4.1 3.7 4.2 4.0

Delphi 3.3 3.0 3.5 3.3

Pioneer 3.3 2.5 3.4 3.5

Lower Severe/Upper SevereLower Severe/Upper

ModerateLower Moderate/Upper

SevereLower Moderate/Upper

Moderate

Moderate level of Interference: -10dB < D/U <-20dBSevere level of Interference: D/U < -20dB

30

Figure 20 - Digital and Analog Performance with Dual Second Adjacent Channel Interferers - Speech The digital system demonstrates equivalent improvements over analog with multipath interference. With both music and speech selections, as shown in Figures 21 and 22 the digital system has only slight degradation as multipath interference increases from weak to moderate and then severe. This contrasts dramatically with the performance of the analog receivers. In both cases, the subjective evaluation of the analog receivers decreases quickly as the multipath interference increases. Moreover, the difference between the digital and analog scores increases substantially as the multipath conditions worsen.

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

IBOC 3.8 3.7

Delphi 3.4 3.0

Pioneer 3.1 2.8

Lower Severe/Upper Severe Lower Moderate/Upper Moderate

Moderate level of Interference: -10dB < D/U <-20dBSevere level of Interference: D/U < -20dB

31

Figure 21 - Digital Performance in Weak, Moderate And Severe Multipath Conditions - Music

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

IBOC 4.4 4.2 4.0

Delphi 3.7 3.0 2.5

Pioneer 3.7 2.6 2.0

Weak Moderate Severe

32

Figure 22 - Digital Performance in Weak, Moderate And Severe Multipath Conditions - Speech

2. Ticker Test The Ticker Test, which used a different methodology from the rest of the performance tests, demonstrated the superior durability of the digital system. The methodology and results of the “Ticker” Test are found in Appendix K. Participants in this test indicated analog radio is much more impaired than digital and that the impairments in analog degrade the overall evaluation of analog. In this test, listeners were asked to evaluate longer audio segments from the digital receiver and both analog auto radios. Listeners were asked to indicate every impairment they heard, no matter how small, and to distinguish between weak and strong impairments.

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

IBOC 4.4 4.4 4.1

Delphi 3.3 3.1 2.5

Pioneer 3.0 2.7 2.0

Weak Moderate Severe

33

In order to aggregate results from this test, all minor, or soft impairments participants reported were classified as “weak”, and all large, or loud impairments were classified as “severe”. Figure 23 shows the total number of temporal impairments reported by all participants for each 4-minute segment. As is evident from this figure, participants heard 4-5 times the number of impairments on the analog segments that they heard on the IBOC segments. Even more importantly, the number of severe impairments participants reported hearing on the analog segments was 6-7 times greater than on IBOC segments. iBiquity believes the number of impairments heard from the digital recordings would be consistent with what would be heard listening to a CD.

Figure 23 - Number of Temporal Impairments Heard on Average

It is interesting to note the IBOC impairments are fairly evenly distributed throughout the segments, indicating that, in general, participants were reporting low-level, uniform impairments. In contrast, the impairments from analog segments were more defined, clustered more heavily around certain points. This pattern indicates that the impairments were more likely to be “rapid-fire”, as would be found in multipath environments.

179.68

844.08

1009.70

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

Tick

s

IBOC

Delphi

Pioneer

34

Figure 24 – MOS Scores for Audio Segments from Ticker

Figure 24 shows mean opinion scores participants gave to the audio segments in this experiment. In both moderately and severely impaired cases, the IBOC receiver consistently scored over 4.1, indicating that participants were satisfied with the level of audio they heard, in spite of reporting occasional temporal impairments. In contrast, in moderately impaired conditions, the analog receivers scored only between 3.1 and 3.4, and in severely impaired conditions received scores of between 2.4 and 2.7, indicating that participants were significantly less satisfied with the quality of this reception. These results show that participants not only clearly heard temporal impairments over long periods of time, but that the quality ratings they assigned were directly affected by the frequency and magnitude of these impairments. Because IBOC eliminates significant temporal impairments as compared to FM analog transmission-reception systems, even in areas close to the transmitter, this results in a marked improvement in audio quality and durability.

Temporal impairments heard at moderate and severe levels

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MO

S

IBOC 4.4 4.3 4.1 4.2 4.3 4.2

Delphi 3.4 3.1 3.2 2.7 2.7 2.4

Pioneer 3.3 3.2 3.2 2.5 2.4 2.4

Classical Country Speech Classical Country Speech

Moderate level Severe level

35

D. Acquisition Performance iBiquity designed its IBOC technology to offer acquisition performance comparable to that found in existing analog receivers. The IBOC system incorporates a blend function that allows the system to acquire the analog signal instantly. This ensures that the listener immediately hears audio after tuning to a station. The system automatically blends to digital as the digital signal is acquired. As a result, system design ensures signal acquisition can never be slower than acquisition of existing analog radio. Laboratory tests confirm the functionality of this element of the system design. The laboratory tests revealed that the system acquired the signal and offered a listenable signal in 135 milliseconds on average. This is comparable to typical analog receiver signal acquisition.

E. Auxiliary Data Capacity

Digital technology converts music, speech, text and graphical information into a digital bit stream. Like other digital communications systems, IBOC is capable of transmitting both audio services and a variety of wireless data services. At the most basic level, IBOC will enable radio broadcasters to transmit data related to the digital audio programming, including song title, artist, and station information. The initial receiver applications are expected to include the ability to display simple text information related to the audio programming. Additional IBOC data services are expected to include the delivery of paging-like services, including traffic, weather, sports scores, stock quotes, and targeted messages. Digital technology will also enable IBOC receivers to store, replay and potentially download digital audio programming, low-bit rate on-demand audio and text-to-speech applications, and other features that allow radio to become a more personalized, on-demand service. Future digital receiver functionality is expected to enable enhanced advertising services that include the capability to deliver location-based advertisements, electronic coupons, and a “more information” service that allows listeners to opt for additional related content. Finally, by coupling the iBiquity system technology --a low-cost broadcast downlink -- with a communications uplink (e.g., in-vehicle cell phone), radio broadcasters can potentially provide navigation and concierge services, on-demand entertainment, and the opportunity for listeners to purchase programming-related music, concert tickets, sports tickets, and books.

iBiquity has developed a layered protocol design that supports the delivery of compressed audio, short messages related to the audio programming, fast-tuning radio station related information, non-program related short-text messages and files, and the opportunity for specialized applications to interact through an applications programming interface (API) with the IBOC transport layer. The layered protocol will allow a large number of service providers and applications developers to interact with the IBOC system through an API without requiring detailed knowledge of the system. The approach will enable IBOC to be implemented with an initial set of value-added data services with the flexibility for new services to be implemented as they become commercially viable for broadcasters and device manufacturers.

36

While FM subcarriers are now used to deliver ancillary data for many applications, IBOC is designed to accommodate a larger volume of data with greater reliability and the potential to reach a greater number of receiving devices at a lower cost per transmission.

iBiquity anticipates that the initial receivers will support program associated data applications. iBiquity expects service offerings and digital receiver features to expand rapidly. The types of data services available to consumers will depend on broadcaster’s decisions regarding audio quality and data capacity. The hybrid system will support a limited amount of data when a broadcaster is utilizing the highest possible digital and analog audio quality. Broadcasters can gain additional data capacity by adopting one of the extended hybrid modes and adding additional digital carriers closer to the analog host. By adding digital carriers in 1, 2 or 4 frequency partitions (122.5 –129.4 kHz, 115.6-122.5 kHz, and 101.7-115.6 kHz) a broadcaster can increase data capacity by up to 50 kbps. However, as broadcasters add partitions closer to the analog host they increase the potential for host compatibility problems on certain lower quality fixed analog receivers. Broadcasters will also have the ability to increase data throughput by reducing the amount of audio throughput. Reducing audio throughput from 96 kbps to 64 kbps, the digital audio quality level used in both satellite DARS systems, increases data capacity by 32 kbps. Broadcasters will have the flexibility to adjust digital audio quality in 8 kbps steps, providing substantial flexibility in capacity tradeoff decisions. For example, a broadcaster may decide to operate with the highest possible digital audio quality (96 kbps) in the morning drive time with minimal data capacity. However, in the late night hours the broadcaster may reduce audio throughhput to 48 kbps thereby increasing data capacity by 48 kbps, without requiring the extended hybrid carriers. This flexibility to trade off audio throughput for data capacity continues in the all-digital mode, however substantially more data capacity will become available. As Table 6 summarizes, broadcasters have tremendous flexibility to tailor their audio and data throughput based on the needs of their listeners in all modes of implementation:

Highest Possible Digital Audio

Quality (96 kbps)

DARS-Level Digital Audio

Quality (64 kbps) Hybrid 1 kbps 33 kbps Extended Hybrid 51 kbps 83 kbps All Digital 181 kbps 213 kbps

Table 6 – IBOC Data Throughput Rates

As the table suggests, there is an inherent trade-off between audio quality and wireless data transmission rates. With IBOC and other digital systems, the higher the wireless data throughput rates, the lower the audio throughput. The flexibility to make these trade-offs will be at the discretion of radio broadcasters.

37

An additional feature that is unique to IBOC is the availability of an additional 2-3 kbps of opportunistic data. iBiquity’s audio compression technology is capable of identifying situations where the audio/speech content is not making full use of the bandwidth allocated to audio services. In these situations, the codec is capable of reallocating the bandwidth for data services. This additional 2-3 kbps is in addition to the data rates in the table above. This minimal amount of opportunistic data capacity would be enough to support most RBDS type services.

iBiquity anticipates that many broadcasters in the hybrid mode may choose to broadcast digital audio quality at the same throughput as the DARS systems. In this scenario, the 33 kbps of data capacity would exceed the data capacity of the current generation of mobile phones, which ranges from 9 to 19 kbps and would be similar to the effective throughput of GPRS technology currently being implemented by many cellular carriers. By operating at DARS-level digital audio quality and adding the extended hybrid partitions, a broadcaster would increase capacity to 81 kbps of data, well in excess of a typical telephone modem. All-digital data rates are comparable to the effective mobile throughput for the cellular industry’s planned upgrade to third-generation technologies (CDMA2000, W-CDMA, UTMS). iBiquity believes that radio broadcasters by adopting IBOC have the lowest cost means of transmitting wireless data and sufficient and flexible capacity to remain competitive with other digital communications systems.

F. Behavior as Signal Degrades Digital systems typically are characterized by abrupt drop off of the signal at the edge of coverage. Sudden loss of the digital signal can be disturbing to listeners, particularly in the case of radio. Existing radio listeners are accustomed to a gradual loss of the analog signal as it becomes increasingly degraded from interference or impairments. iBiquity designed its system with the blend-to-analog function to address this problem. As the digital signal degrades, the system tracks the number of frame errors being experienced. At a predetermined error rate, the system blends to analog. This blend function plays a dual role as the digital signal degrades. First, it allows the system to blend from the digital signal before the appearance of digital artifacts that are normally associated with the edge of digital coverage. Second, it facilitates a more gradual loss of the audio. Even though analog typically is quite degraded at the point of failure of the digital signal, this blend function ensures a more gradual loss of the audio in a manner that mirrors the experience a listener has with analog radio. In order to examine the effect of digital/analog blending on the audio quality of iBiquity’s digital receiver, a Point-of-Blend experiment was conducted at Dynastat. Although blending is a particularly important feature of iBiquity’s system, it is a function, not a “condition”. Because blend audio samples include both digital and analog segments as well as the point-of-blend, it is likely that participants’ overall quality ratings are derived from their impression of the entire audio segment, including the various analog and digital components. It is important to note that because it is likely that the analog component of the IBOC receiver will only get better in production, it was felt that resulting data from this experiment would be an extremely conservative measure of how

38

people perceived blend-to-analog. As Figure 25 below illustrates, there was no meaningful difference in the evaluation of digital selections including blends when compared with the evaluation of the same selections only in analog.

Figure 25 - Performance of the Digital System with Blend Conditions

These results were obtained with both music and speech selections. These results prove blend-to-analog provides an acceptable means of creating a graceful degradation of the digital signal.

G. Stereo Separation Stereo separation was not addressed directly by any of the tests in the NRSC test procedures. In the subjective evaluation tests participants were not asked about how stereo imagery affected their opinion of the samples they heard. Thus, it is difficult to discern the role that stereo imagery played in their judgment of the IBOC and analog samples. However, it is important to note that one of the hallmarks of digital radio is that stereo imagery is preserved whenever the system is operating in the digital mode. The digital system avoids the shrinking and displacement of the image that can be found with analog transmission. Therefore, we believe that the preservation of stereo imagery contributed to participants’ high IBOC scores during performance testing.

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H. Flexibility The iBiquity system provides tremendous flexibility for broadcasters to meet the needs of their listeners and for equipment manufacturers to address the demands of consumers. IBOC technology, by definition, affords flexibility to all components of the broadcast industry. Because IBOC allows for the introduction of the digital signal in the existing analog band, it permits broadcasters to introduce digital service alongside existing analog service. The simulcasting concept inherent in IBOC allows for a gradual transition from analog broadcasting to digital. This will give broadcasters and listeners the flexibility to upgrade to digital as part of the normal equipment replacement cycle, thus minimizing disruption and expense. iBiquity also designed specific elements of the system to increase functional flexibility for broadcasters and equipment manufacturers. For example, the system supports new datacasting services that will allow broadcasters to offer new features to listeners. The system enables broadcasters to make tradeoffs between audio quality and robustness to increase their datacasting capacity The system also includes specific design elements to ensure compatibility with new services or features to be developed in the future. For example, the system will allow for enhancements to be derived from all-digital broadcasting without creating obsolescence issues for receivers developed for the hybrid mode. Similarly, new data services will be introduced gradually as they are developed without impacting the ability of early generation receivers to continue to receive the basic digital audio services. For a full description of overall system flexibility, see Appendix A

I. Host Compatibility The test program confirmed that the IBOC system causes no harm to the analog operations of the host station. For purposes of this discussion, “host” is used to mean the station which has adopted hybrid IBOC broadcasting to allow for simultaneous analog and digital broadcasts. The tests confirm that the newly introduced digital signal will not degrade the analog operation of the same station.14 An analysis of the subjective evaluation of the host compatibility test results indicates there is no meaningful difference between the scores of the host analog signal without IBOC and with IBOC. These tests were conducted by recording analog reception on all four analog radios with IBOC turned off. After IBOC was introduced, audio samples of the station’s audio were recorded using the same four receivers. Figure 26 below illustrates that the subjective evaluators found no impact from the introduction of IBOC, both with speech and with music audio samples.

14 This report addresses only the impact of IBOC on main channel audio. A discussion of the impact on

SCA operations will be submitted to the NRSC at a later date.

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Figure 26 - IBOC Compatibility with Host Main Audio in the Field

J. Non-Host Compatibility

1. First Adjacent Compatibility

IBOC is designed to use existing spectrum efficiently and to preserve current

analog broadcasts for as long an analog to digital transition period as is necessary. In hybrid mode, the system design accomplishes these objectives by placing low level digital signals in the sidebands of the host analog signal, and transmitting analog and digital simultaneously. The introduction of this additional digital energy in the FM band has, by definition, the potential to introduce new interference, particularly to first adjacent analog broadcasts. iBiquity has optimized its system design to provide the greatest possible benefits from IBOC, as evidenced by the superior audio, coverage and durability results detailed above, while at the same time ensuring the highest level of compatibility with the existing analog broadcast. In this regard, iBiquity has conducted not only the compatibility tests prescribed by the NRSC, but has also completed detailed station, market and listener analysis and extensive field trials to quantify the potential real world impact of digital interference on the existing FM broadcast infrastructure. Taken together, these results indicate the introduction of IBOC will have no meaningful impact on FM analog broadcasting resulting from increased first adjacent interference.

Field Host Compatibility

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First Adjacent Channel Interference Incidence of Interference on All FM Stations

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Field test results on first adjacent compatibility, completed at the interference levels set forth by the NRSC, though not conclusive, do indicate some potential impact on analog first adjacent stations. To be understood correctly, however, this potential impact must be analyzed in conjunction with the actual incidence of these interference levels in the FM band. Detailed FM station analyses conducted by iBiquity, using data provided by dataworld and Arbitron, show that the actual coverage area potentially impacted by IBOC first adjacent interference is very small, and that within that limited area, the number of existing listeners is exceedingly small. All told, iBiquity’s studies conclude that in the worst possible scenario, on average, only 0.6% of any given FM station’s existing analog listeners will experience any impact from the introduction of IBOC, meaning 99.4% will be unaffected. This analysis is borne out by iBiquity’s extensive and successful field trial record. Over a period of more than two years, iBiquity has broadcast IBOC on commercial stations in some of the nation’s most interference intensive markets without any reported impact to the analog broadcasts.

a. Field Test Results on First Adjacent Compatibility

The field tests indicate IBOC has a minimal impact in several first adjacent compatibility situations at the interference levels prescribed by the NRSC. As Figure 27 illustrates, on an aggregate basis, the field test results show an insignificant impact, particularly for music genres. In the majority of cases, a slight degradation of audio

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Figure 27 - Field First Adjacent Compatibility Results for All Conditions

quality was measured after the introduction of IBOC, but at levels which would not have a material impact on listening as detailed in the MOS analysis below.

The MOS interpretation test is particularly useful in analyzing these results. Although the differential in MOS scores with IBOC on and off may be useful in the abstract, it does not communicate the impact on the desired station’s listeners. The MOS interpretation test, described fully in Appendix J, helps assess whether increased interference from digital will have any impact on listenership. The MOS interpretation test indicted that the average listener would not be motivated to change stations or turn off the audio until an MOS score of 2.0 or lower for Rock, 2.1 or lower for Classical and 2.3 or lower for Speech. Thus, one can conclude that in those cases where the IBOC signal may have an impact on analog reception, the impact is not meaningful because it will not cause any change in listener behavior. Only in a case where the “IBOC On” impact results in scores below these levels would there be any significant impact on listening habits. The field test results did not indicate this level of impact in the vast majority of cases.

Figure 28 displays the potential impact of IBOC on first adjacent analog for music genres, shown by receiver tested and interference level. A small but insignificant impact is measured in most cases, however, the predicted impact will not result in changes to listener behavior based on MOS scores. Figure 29 displays this same data for speech. Here, a more pronounced impact is measured, most likely due to the limited masking effects of speech content. Interference introduced by IBOC can often be manifested by a

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low level hiss, not unlike that occurring naturally in FM reception. This hiss is effectively masked by music, but is more easily detected by listeners with the lower density of speech. It is likely that as receiver manufacturers introduce new receivers, they will incorporate new noise cancellation techniques, lessening any potential impact even further. Again, in the majority of cases for speech, the MOS scores recorded with IBOC on will not result in changes in listener behavior.

Figure 28 – Field Compatibility with 1st Adjacent Interferers At Moderate and Severe Levels – Music

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Figure 29 - Field Compatibility with 1st Adjacent Interferers

At Moderate and Severe Levels – Speech

Results for first adjacent compatibility with music in the presence of multipath also show an insignificant overall impact, as displayed in Figure 30.

On balance, these field tests, though not conclusive, predict a quantifiable but not meaningful impact on first adjacent analog stations from the introduction of IBOC at the interference measurement levels prescribed by the NRSC. In the vast majority of cases, this slight impact is predicted to have no meaningful effect on listener behavior. It is anticipated that over time, receiver technology will effectively cancel these effects. Finally, as detailed below, the relatively rare instances of these levels of interference to actual listeners leads to the conclusion that IBOC will have no meaningful impact on FM listening resulting from first adjacent channel interference.

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Figure 30 - First Adjacent Field Compatibility with Multipath – Music

b. Predicted Impact of IBOC Introduction on First Adjacent

Analog Broadcast

Both the laboratory and field tests of first adjacent compatibility were designed to stress the system beyond normal levels of interference to define the point of failure. They say nothing at all about the actual incidence of such interference, and therefore, taken by themselves, cannot be predictive of the potential impact IBOC will have on first adjacent stations. In an effort to more accurately quantify this impact, iBiquity conducted several additional studies on actual station interference levels, coverage areas, and listening patterns across the FM band. Appendix L, completed by iBiquity using data provided by dataworld, details the existing analog first adjacent interference levels experienced by FM stations across the country. dataworld is a leading information services firm providing customized mapping and statistical data to the communications industry. Appendix M, completed by iBiquity using data provided by dataworld and Arbitron, is a statistical analysis of the predicted impact on listeners from first adjacent channel interference resulting from the introduction of IBOC. Taken as a whole, the conclusion drawn from these studies is that IBOC will have no meaningful impact on first adjacent analog listening.

As part of its system design efforts, iBiquity engaged dataworld to provide a

comprehensive analysis of first adjacent analog interference in the FM band. The goal of the analysis, detailed in Appendix L, was to determine the overall coverage area of existing FM stations subject to varying levels of first adjacent analog interference. The results are displayed below in Figure 31, which shows that the vast majority of coverage

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area is not subject to levels of interference where any potential impact from IBOC could occur.

Inside the 54 dBu contour (the protected contour for a Class B station), less than 1% of the overall FM coverage at an interference level of 0 dB D/U is potentially impacted. At an upper limit of potential IBOC first adjacent impact at +6 dB D/U, only 3.1% of FM coverage area is potentially affected15. To be conservative, a similar analysis was also completed at the 44 dBu contour, which was assumed to represent the noise-limited listening area for any particular station. This is an area that extends well beyond a station’s protected contour. For WPOC, a typical Class B station, assuming the coverage area extends to the 44 dBu contour from the 54 dBu contour, coverage area increase from 5026 square miles to 9503 square miles, an 89% increase16. Even at this very conservative level, the vast majority of FM coverage area will experience no impact from IBOC introduction. At 0 dB D/U, 10% of FM coverage area will be potentially impacted, and at the upper limit of +6 db D/U, 20% will be potentially impacted. It is evident, then, that the vast majority of any potential IBOC impact will occur outside a station’s protected contour.

Figure 31 – First Adjacent Channel Interference

15 :The estimates of potential impact inside the protected contour are in reality overstated. This is because the analysis assumed a uniform protected contour at 54 dBu across all FM stations. This is true only for Class B stations. Class A and Class C stations are protected only to 60 dBu. Including this complexity would reduce the overall estimates. 16 At the 54 dBu contour, WPOC’s average coverage radius from the transmitter is 40 miles. At the 44 dBu contour, it is 55 miles.

First Adjacent Channel Interference Incidence of Interference on All FM Stations

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Incidence on All FM Stations

The fact that almost all of the area of potential impact occurs outside a station’s protected contour was demonstrated by the field tests, as displayed in Figure 32. This figure shows the measurement locations of the first adjacent compatibility tests for WETA, which were all conducted at points at the edge of or outside the desired station’s (WMRA) protected contour. The selection of these sites was dictated by the need to find interference ratios severe enough for IBOC to have any potential impact on the desired first adjacent analog signal. The figure also shows that the vast majority of first adjacent interference that might lead to IBOC impact is located outside WMRA’s protected contour.

Figure 32 - WETA 1st Adjacent Interference Test Locations

To assess the potential impact of IBOC introduction on FM first adjacent channel

listeners, iBiquity conducted statistical and laboratory analysis using information provided by dataworld and Arbitron. Appendix M contains the full study. As could be inferred from the very limited incidence of first adjacent interference described above, this study definitively concluded that a large-scale national rollout of IBOC would have an immaterial effect on analog radio broadcasters and listeners.

The study was designed to quantify the potential impact to analog FM station listenership caused by the introduction of IBOC at various power levels. To accomplish

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this, a representative sample of analog radio receivers was selected and subjectively tested for point of failure (POF) for both analog alone and analog impacted by IBOC. Then coverage modeling was completed on a statistically valid, random sample of radio stations. Coverage was modeled with IBOC off and IBOC on at various power levels, and the IBOC impact quantified. Finally, the impacted coverage areas were overlaid with actual listener data obtained from Arbitron. In this way, the study was able to quantify the number of actual listeners potentially impacted by IBOC introduction.

As displayed in Figure 33, the study concluded that on average, 99.4% of an FM station’s listeners will not be impacted by the introduction of IBOC at a power level of –23dBu, even in the event all first adjacent radio stations implement IBOC. This result ties very logically to the interference studies described above. In essence, IBOC only has potential impact on very small coverage areas for a given first adjacent station, and most of this area lies outside the station’s protected contour. It follows that an exceedingly small number of listeners are expected statistically to be in these impacted coverage areas. The study results support this conclusion.

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Further, the study’s finding that, on average, 99.4% of an FM station’s listeners

will not be impacted by IBOC introduction, is most likely understated for three reasons. First, IBOC will be implemented over a number of years and the impact to a station will not reflect the study findings until all first adjacents adopt IBOC. Second, future

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advances in transmission and receiver technology will serve to reduce the analog listener impact. Finally, over time, listeners are expected to substitute digital receivers for analog receivers further reducing the analog listener impact. As a result, the actual percentage of listeners impacted is likely to be even less than the insignificant number observed in the study.

Taken as a whole then, the first adjacent compatibility tests and accompanying studies on actual interference levels and predicted listener impact clearly demonstrate that the introduction of IBOC will have no meaningful impact on FM analog broadcasting due to the impact of increased first adjacent interference. This conclusion is further supported by the extensive real world field trials conducted by iBiquity, as detailed below.

c. Results of Field Trials Indicating Impact of IBOC Introduction on First Adjacent Analog Broadcast

iBiquity began on-air field trials of its final IBOC system on commercial FM

stations in June 1998, and has amassed substantial data on the performance and impact of IBOC in the real world. Much of this testing was designed to assess the impact of IBOC’s introduction on first adjacent analog stations and was conducted on stations located in some of the most interference intensive markets in the U.S. More details from the field trail results are shown in Appendix N. The results of these multi-year field trials are conclusive - no impact from the introduction of IBOC was observed on any first adjacent station.

During this period, 11 FM commercial stations in 7 markets were been converted

to IBOC and tested and/or demonstrated to the public accumulating an estimated 8.5 on-air years of total operation. In addition, IBOC was broadcast by several of these stations for lengthy periods of time, and frequently operated at IBOC power levels significantly greater than those to be used commercially, to test the effects of IBOC on first adjacent stations. The testing of any impact to first adjacents included monitoring for any complaints from listeners, station staff, auto or receiver manufacturers or regulators, and monitoring any unexplained changes in Arbitron ratings. Of the 11 stations, 6 are of interest since they have close-spaced first adjacents. The stations are shown in Table 7.

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WPOC Baltimore 1st Adjacents South and Northeast

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WNEW New York High antenna, 1st Adjacent Southwest

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WHFS Annapolis MD

Twin 1st adjacents Southeast

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75 kW Class B Oct 99 Ongoing 3 17

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adjacent. High power testing

WJFK Washington DC

Moved-in station with strong upper and lower 1st adjacents

Nov 99 Dec 00 - 13

All Others KLLC KWNR WMMO WGRV

San Francisco, Columbia, Las Vegas, Orlando, Detroit

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Total On Air Time = 103 Months (8.5 years) Table 7: IBOC Field Trial Stations

After close monitoring of the stations and their first adjacents during the entire

trial period, no known complaints have been received, and no unexplained impact to Arbitron ratings have been observed. This extensive record provides further evidence from the real world that the introduction of IBOC will have no impact on first adjacent stations.

The trial experience at two stations located in the interference intensive Baltimore/Washington market, WPOC and WJFK, is important to highlight. WPOC has coverage from Washington DC to Maryland’s eastern shore and is situated between two upper first adjacents at 93.3 MHz and two lower first adjacents at 92.9 MHz as shown in Figure 34. Of the four stations, WFLS and WDSD theoretically would have the greatest potential to receive IBOC interference from WPOC due to the flat terrain and short spacing.

For a period of 12 months out of the nearly 2 years WPOC has been on the air, the IBOC sidebands were transmitted at twice the –20dBc proposed digital power level to determine worst case of potential interference to the surrounding stations. Even at these elevated power levels, and despite the short spacing, there has been no known impact from the introduction of IBOC on WPOC’s first adjacents.

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Call Sign ST City Freq. ERP [W] Class Distance from WPOC [mi]

WDHC WV BERKELEY SPRINGS 92.9 6000 A 81.49 WDSD DE SMYRNA 92.9 1700 A 64.07

WFLS-FM VA FREDERICKSBURG 93.3 50000 B 76.68 WMMR PA PHILADELPHIA 93.3 18000 B 96.29

Figure 34: WPOC FCC Interfering Contour

WJFK is one of the most severe coverage impacted stations in the country. The station, licensed to Manassas, Virginia, was located closer to Washington to reach into the district. As a result, its interfering contour overlaps with substantial portions of its lower first adjacent WWMX, only 44 miles away in Baltimore, and its upper first adjacent WARX only 47 miles away in Hagerstown, Maryland as shown in Figure 35. WJFK and WWMX are commonly owned stations with one engineering staff. During the test program, the station’s engineers were in contact on a regular basis and jointly

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investigated areas of potential interference. In areas where IBOC interference related to IBOC could be detected, analog reception was already severely impacted

Call Sign ST City Freq. ERP [W] Class Distance [mi] WRCL VA RICHMOND 106.5 7600 B 98

WWMX MD BALTIMORE 106.5 7400 B 44.33 WARX MD HAGERSTOWN 106.9 15500 B 47.63

Figure 35: WJFK FCC Interfering Contour

Since WJFK represents a worst case interference scenario, iBiquity worked closely

with a major automotive receiver manufacturer to investigate if there were any returns of autos in the Baltimore-Washington area for radio receiver warranty work based on not being able to receive WWMX or WARX (or any reception problem that could be attributed indirectly to IBOC). This investigation concluded that there was no connection between IBOC introduction and the normal warranty claims. As with WPOC and all other stations, there was no reported complaints from listeners, station staff, auto or receiver manufacturers or regulators, and no unexplained changes in Arbitron ratings.

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d. Conclusions on First Adjacent Compatibility of IBOC

Examining the full test record put forth above leads to a definitive conclusion: the introduction of IBOC will have no meaningful impact on FM analog broadcasting resulting from increased first adjacent interference. Although field test results indicate some potential impact on analog first adjacents, further analysis of the real world situation demonstrates that the incidence of this potential impact is not meaningful. Detailed analysis of every FM station across the country shows that the actual coverage area potentially impacted by IBOC first adjacent interference is very small. Further, analysis of existing listening patterns demonstrates that within the limited area potentially affected, the number of existing listeners is exceedingly small. In the worst possible scenario, an average of only 0.6% of any given FM station’s existing analog listeners will experience any impact from the introduction of IBOC. This analysis is supported by iBiquity’s extensive field trial record: over a period of 24 months, iBiquity has broadcast IBOC on commercial stations in some of the nation’s most interference intensive markets without any reported impact to the analog broadcasts whatsoever.

2. Second Adjacent Compatibility

The tests confirmed the introduction of IBOC does not harm second adjacent channel

analog operations. Because the NRSC test procedures did not require field testing with second adjacent interference, only lab test results are available for this element of the test program. As Figures 36 and 37 illustrate, the introduction of IBOC had no impact on second adjacents for the automobile receivers. Both the portable and the home receiver failed the test at -40 dB due to front-end overload unrelated to the introduction of IBOC. As a result, they were tested at -30 dB. The Sony receiver continued to exhibit failure at -30 and -20 dB. The Technics receiver exhibited an insignificant impact from IBOC at those levels. As a result, the tests should be interpreted to indicate the introduction of IBOC does not have a meaningful impact in this condition.

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Figure 36 - Lab Compatibility with 2nd Adjacent Interferers – Music

Lab Compatibility with 2nd Adjacent Interference - Music

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Figure 37 - Lab Compatibility with 2nd Adjacent Interference - Speech

III. Conclusions This report and the supporting appendices demonstrate conclusively the benefits of IBOC, including its superior audio quality and robustness when compared to existing analog FM service. In addition, the report details that the introduction of IBOC will have no meaningful impact on existing analog stations and virtually no impact on analog listeners. Consequently, iBiquity encourages the NRSC to provide a strong endorsement of iBiquity’s IBOC system in order to encourage prompt regulatory action to approve IBOC and to encourage the final standardization of this technology.

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LIST OF APPENDICES Appendix A IBOC FM Transmission Specification Appendix B Laboratory Test Platform Appendix C Laboratory Test Procedures for the ATTC Appendix D ATTC Summary of Test Results Appendix E FM Field Test Procedures and Notes Appendix F Field Test Results F.1 WETA F.2 WPOC F.3 WHFS F.4 WNEW F.5 WWIN F.6 KWNR F.7 KLLC F.8 WD2XAB F.9 Compatibility Appendix G Subjective Testing Program and Platform Appendix H Dynastat – Audio Testing Methods and Procedures Appendix I FM Subjective Evaluation Results Appendix J Summary of MOS Interpretation Test (Ellyn) Appendix K Ticker Test Appendix L Study of the Present Levels and Instances of First Adjacent

Channel Interference Appendix M Impact of National Rollout of IBOC on Analog Radio Listenership Appendix N On-Air IBOC Field Trail Record