1xEV-DO White Paper by RAN + Handset

7/28/2019 1xEV-DO White Paper by RAN + Handset

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White Paper

Prepared by

Work Groups 9 & 10Infocomm Technology Centre

Reliance Infocomm

December 2003


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1xEV-DO Overview December 2003

Copyright 2003, Reliance Infocomm Limited. All rights reserved.

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Technical Contact:Standardization Division,1CA07, 1st Floor, J-Block,Dhirubhai Ambani Knowledge City,Navi Mumbai - 400709

[email protected]


Trademark AcknowledgmentsAll brand or product names are trademarks of their respective companies ororganizations.


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December 2003 1xEV-DO Overview


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Table of Contents

1 Introduction.............................................................................................................1

1.1 Voice vs. Data...................................................................................................1

1.2 Standards .........................................................................................................2

2 EV-DO Airlink..........................................................................................................3

2.1 Network Reference Model.................................................................................32.2 Channel Structure .............................................................................................3

2.2.1 Forward Link Transmit Power ....................................................................42.2.2 Source Identification...................................................................................42.2.3 Turbo Codes ..............................................................................................52.2.4 Higher Order Modulation............................................................................5

2.3 Features for Optimizing Data Operation ............................................................62.3.1 Forward Link Hybrid ARQ ..........................................................................62.3.2 Scheduling .................................................................................................7

2.3.3 Virtual Soft Handoff....................................................................................72.4 Protocol Stack...................................................................................................8

2.4.1 Application Layer .......................................................................................92.4.2 Stream Layer .............................................................................................92.4.3 Session Layer ............................................................................................92.4.4 Connection Layer.....................................................................................102.4.5 Security Layer..........................................................................................102.4.6 MAC Layer...............................................................................................102.4.7 Physical Layer..........................................................................................10

2.5 Characteristics ................................................................................................102.5.1 Throughputs.............................................................................................102.5.2 Handoff to 1x............................................................................................12

2.5.3 Receive Diversity .....................................................................................12

3 Physical Layer.......................................................................................................13

3.1 Forward link ....................................................................................................133.1.1 Forward Link Channel Structure...............................................................13

3.2 Reverse Link...................................................................................................163.2.1 Reverse Link Channel Structure...............................................................16

4 Network .................................................................................................................18

4.1 Impact of 1xEV-DO on Radio Access Network................................................184.2 Chipset............................................................................................................18

4.2.1 CSM5500 Chipset....................................................................................18

4.2.2

CSM6800 Chipset....................................................................................18

4.3 Add on Cards in BTS ......................................................................................194.3.1 Data Only Module (DOM).........................................................................194.3.2 Data Only EMS ........................................................................................19

4.4 Access Network AAA Server...........................................................................204.5 Network Rollout with 1xEV-DO and CDMA2000 1X ........................................20

5 Handset .................................................................................................................20

5.1 Chipset............................................................................................................20


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5.2 Models ............................................................................................................235.3 Testing of Mobiles...........................................................................................25

6 Applications and Services ...................................................................................26

6.1 Push to Talk....................................................................................................266.2 Location Based Services.................................................................................27

6.3 Video...............................................................................................................286.4 Instant Multi-Media..........................................................................................28

7 Comparison...........................................................................................................29

8 Summary...............................................................................................................30

Appendix A: 1xEV-DO Compatible Mobiles...............................................................31


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List of Tables

Table 1: Forward Link Channel Parameters ....................................................................5Table 2: Reverse Link Channel Parameters ....................................................................6Table 3: Forward Link Throughput.................................................................................11

Table 4: Features of Qualcomm Chipsets for Mobiles ...................................................21Table 5: 1xEV-DO Compatible Mobiles .........................................................................23Table 6: 1xEV-DO Compatible Data Cards ...................................................................24


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So, if the Network is optimum for voice then it may not be optimum for the data and viceversa. With that in mind, the 1xEV-DO design requires a separate CDMA carrier.

1.2 Standards

The relevant standards involved in 1xEV-DO are listed below:

IS-856, Cdma2000 High Rate Packet Data Air Interface Specification

This specification is primarily oriented toward requirements necessary for thedesign and implementation of access terminals. As a result, detailed proceduresare specified for access terminals to ensure a uniform response to all accessnetworks. Access network procedures, however, are specified only to the extentnecessary for compatibility with those specified for the access terminal.This specification includes provisions for future service additions and expansionof system capabilities. This compatibility standard is based upon spectrumallocations that have been defined by various governmental administrations.

IS-866, 1xEV-DO Access Terminal Minimum Performance Specification

This Standard details methods of measurement, and minimum performancecharacteristics for access terminals.

IS-864, Access Network Minimum Performance Specification

This Standard details definitions, methods of measurement, and minimumperformance requirements for access networks. Test methods are recommendedin this document.

IS-878, 1xEV-DO Interoperability Access Network

The interfaces defined in this document are compatible with A-interface. Thisdocument describes the protocol and some generic procedures to support theHigh Rate Packet Data (HRPD) IOS (Inter-Operability System) features.

IS-890-1, TestApplication Specification

This standard specifies technical requirements for test applications in cdma2000high rate packet data systems. This specification is primarily oriented towardrequirements necessary for the design and implementation of access terminals.As a result, detailed procedures are specified for access terminals to ensure a

uniform response to all access networks.

IS-707, Data service options for Wideband Spread Spectrum Cellular Systems

This standard defines requirements for support of high speed packet datatransmission capability on CDMA2000 spread spectrum systems. This standardspecifies packet data bearer service for communication between terminalequipment and PDSN via a Base Station/packet control function (BS/PCF)


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IS-918, Signaling Conformance Specification for cdma2000 Wireless IPNetworks

This document is to facilitate the interoperability testing between mobile andinfrastructure, as well as provide network specific test cases. Recommendedmethods of measurement, and minimum standards are provided in this standard.

IS-919, Signaling Conformance Specification for High Rate Packet Data AirInterface

These technical requirements form a standard for signaling conformance incdma2000 high rate packet data systems. These requirements ensure thatcompliant access terminals and compliant access networks can execute tests inmeeting the objectives specified. This standard is analogous to its CDMA2000counterpart IS-898

2 EV-DO Airlink

This section provides an overview of the 1xEV-DO technology.

2.1 Network Reference ModelFigure 1 depicts the network reference model of 1xEV-DO.

Figure 1: 1xEV-DO Reference Model

It consists of following entities:

AN: Access networkAT: Access Terminal (Mobile phone)

PCF: Packet Control FunctionAAA: Access Network Authentication, Authorization and Accounting serverPDSN: Packet Data Serving Node

2.2 Channel StructureIn CDMA systems, channelization is utilized to identify various users and/or channels inboth forward and reverse link. In IS-2000, variable length (4 to 128 bit) Walsh codes are


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used in the forward direction. In the reverse direction, statically defined Walsh codes areused to identify a reverse physical channel of a specific user. In 1xEV-DO, the forwardlink channels are time-multiplexed (no Walsh codes) instead of code multiplexed. Here,various forward link channels (see Figure 2) are time multiplexed within a forward linkframe. In the reverse link, channelization scheme is similar to IS-2000 where bothsystems use statically defined Walsh codes.

Figure 2: Channel Structure

2.2.1 Forward Link Transmit Power

For CDMA2000 1xEV-DO, the base station is configured for a set transmit power. Ittransmits at this maximum available power all the time. Instead of some portion of powerbeing allocated all the time to control or overhead channels such as pilot, sync, pagingchannels (in IS-95/IS-2000 systems), the complete full power is allocated to all thechannels in a time-multiplexed fashion. In other words, for the pilot channel, instead of

getting 20-25% of total transmit power continuously as in IS-95/IS-2000 systems, it isallocated 100% power only for a short duration within a forward channel slot. Similarly,the user traffic channel is also given complete 100% of the total transmit power for agiven duration and so forth. This philosophy is called fixed power variable rate where thesector transmits to all the users in a sector at a fixed available transmit power. If the useris near the center of the sector, the user would be able to receive the forward channel atmuch higher data rate. However, a user at the edge of the sector, due to path losses andother interference, would receive the forward channel at much lower data rates bycompensating for increased interference with increased data protection and lower ordermodulation.

2.2.2 Source Identification

In 1xEV-DO systems, the source identification in forward direction is identical as in IS-95/IS-2000. However, in the reverse direction, since the access terminal does not needto have a user specific long code (based on ESN), ESN is not utilized to generate a longcode sequence. Instead, the long code mask is generated based on assigned UnicastAccess Terminal Identifier (UATI). The UATI is a temporary identifier assigned by theaccess network to the access terminal during address management phase of sessionmanagement.


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2.2.3 Turbo Codes

The 1xEV-DO technology incorporates the usage of special class of codes known as theTurbo codes.Turbo codes are a class of error correcting codes. 1xEV-DO utilizes turboencoding in both forward and reverse links. At the expense of increased processing anddelay (which the data services are not sensitive to), turbo encoding provides much

higher data protection compared to convolutional encoding. The increased protectionlevel allows data to be transmitted at lower power, in turn, improving the overallthroughput of the system.

In contrast to IS-2000, where the encoding rates are fixed, the encoding rates in 1XEV-DO are dynamic. Turbo codes have been shown to perform better for high rate data

services with stringent error rate requirements of the order of 10-6

Bit Error Rates (BER).The turbo encoder consists of two constituent convolutional encoders. Each encoderuses a 3-bit shift register with a constraint length of k = 4 and encoding rate of R. Usinga turbo encoder, the forward link coding rate is R = 1/5 or 1/3 while the reverse linkcoding rate is R = 1/2 or 3/4.

2.2.4 Higher Order Modulation1XEV-DO utilizes adaptive modulation where the modulation scheme varies based onthe channel conditions received at the access terminal. If the channel condition is notvery good (the access terminal is at the edge of the cell), the system employs lowerorder modulation. If the channel condition reported by the access terminal is excellent,the system takes advantage of this situation by employing higher order modulation suchas 16-QAM, where four bits of coded bits are mapped to one modulated symbol, in turnbroadcasting more bits over the air and improving the data-rate.

The key forward and reverse link channel parameters of 1xEV-DO are given in Table 1and Table 2 below.

Table 1: Forward Link Channel Parameters

Data rate (kbps) 38.4 76.8 153.6 307.2 307.2 614.4 614.4 921.6 1228.8 1228.8 1843.2 2457.6

Modulation Type QPSK QPSK QPSK QPSK QPSK QPSK QPSK 8 PSK QPSK 16QAM 8 PSK 16QAM

Bits per Encoder packet 1024 1024 1024 1024 2048 1024 2048 3072 2048 4096 3072 4096

Code rate 1/5 1/5 1/5 1/5 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3

Encoder packet duration(ms)

26.67 13.33 6.67 3.33 6.67 1.67 3.33 3.33 1.67 3.33 1.67 1.67

Number of slots 16 8 4 2 4 1 2 2 1 2 1 1


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Table 2: Reverse Link Channel Parameters

Data Rate (kbps)

Parameter 9.6 19.2 38.4 76.8 153.6

Reverse Rate Index 1 2 3 4 5

Bits per physical layerpacket

256 512 1024 2048 4096

Physical layer packetDuration (ms)

26.66 26.66 26.66 26.66 26.66

Code Rate 1/4 1/4 1/4 1/2

Code Symbols perphysical layer packet

1024 2048 4096 8192 8192

Code symbol rate (ksps) 38.4 76.8 153.6 307.2 307.2

Interleaved packet

Repeats8 4 2 1 1

Modulation Symbol Rate(ksps)

307.2 307.2 307.2 307.2 307.2

Modulation type BPSK BPSK BPSK BPSK BPSK

PN Chips per physicallayer packet bit

128 64 32 16 8

2.3 Features for Optimizing Data OperationThis section covers certain features that have been added in 1xEV-DO to optimize data

operation.

Forward Link Hybrid ARQ

Scheduling

Virtual Soft Handoff

2.3.1 Forward Link Hybrid ARQ

In 1xEV-DO, acknowledgment is provided at the physical layer. This provides quickresponse from the receiver (access terminal) to the transmitter (access network). Theaccess network transmits the physical layer packet with proper data protection. Thisinvolves some amount of repetition as well. The entire packet may be split into one or

more (up to 16) slots. If the physical layer packet is split into more than one slot, thenthese slots, instead of transmitting in consecutive slots, are transmitted in multi-slots thatare separated by exactly four slots. This timing allows the access terminal to processand respond with the physical layer acknowledgment (either ACK or NAK). If the accessnetwork receives a NAK for a transmitted slot, it continues the transmission of the nextslot. If it receives an ACK for a transmitted slot, it considers successful transmission ofan entire packet and terminates the transmission of the remaining slots of the currentpacket. This results in increased average throughput for the entire sector.


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For every slot received by the access terminal, a ACK or NAK is sent back to the accessnetwork pending the success of the receipt of the physical layer packet. As the originalpacket sent to the access terminal is transmitted after data protection is applied, it ispossible the access terminal can receive the packet before all four slots are received.This is called early acknowledgement and this method of acknowledgement is calledHybrid automatic repeat request (ARQ)

The Mobile and the Access Point jointly determine each users forward link data. TheMobile measures the pilot strength, and continuously requests an appropriate data ratebased on the channel conditions. The Access Point encodes the forward link at exactlythe highest rate that the subscribers wireless channel can support at any instant.

2.3.2 Scheduling

1xEV-DO is optimized for packet data services, in which all users do not generallydemand equal service. Some applications require higher data rates, while others havemuch lower data rate requirements. The users channel condition (C/I) is also a primaryfactor in determining the data rate that a given subscriber can attain. The 1xEV-DOsystem takes advantage of the wireless channel variability, which results in variations ofthe requested rate over a period of time. The scheduler resides at the Base Station andtakes into account the data rates requested by different Mobiles. The schedulingalgorithm decides which Mobile is served with the requested data rate at any giveninstant. The scheduler is weighted to serve users that improve their signal quality andweighted against users that are experiencing signal degradation. Occasionally, the usersmay not be served for periods of milliseconds when their requested rates are lower. Bythe scheduler selecting the optimal time to transmit data to a user, the users overallmoving average is higher, then if they were served on a first in, first out basis. Thepriority in the scheduler is based on a combination of the C/I as well as the durationsince the last time a user has been served. The disadvantaged users with low C/Iaccumulate credits with the scheduler, increasing their priority in the system and theirthroughput will start to improve.

2.3.3 Virtual Soft Handoff

The 1xEV Mobile receives data only from one Access Point at any given time. Instead ofcombining transmit energy from multiple Access Points, the Mobile is able to rapidlyswitch from communicating from one Access Point to another. This phenomenon isshown in Figure 3. The Mobile measures the channel C/I from all the measurable Pilotchannels and requests service from the Access Point with the strongest Pilot signal. Thisfollows the best server rule, where the Mobile communicates with the requested AccessPoint at any given time. The forward link pilot allows the Mobile to obtain a rapid andaccurate C/I estimate. The 1xEV reverse link, makes use of soft hand-off mechanisms.The Mobiles transmission is received by more than one Access Point, and frame

selection is hence made.


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Figure 3: Virtual Soft Handoff

The Location Update Message enables the Access Network to connect to the PDSNmaintaining the PPP state to the Mobile; therefore it can re-route traffic to the Mobileimmediately upon receiving the Mobiles Location Update Message. This method allowsthe Mobile to maintain its same IP address and same PPP connection; thereforeallowing a seamless handoff.

2.4 Protocol StackThe 1xEV-DO layered architecture enables a modular design that allows partial updates

to protocols, software, and independent protocol negotiation. Figure 4 shows theprotocol stack for 1xEV-DO.


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Figure 4: Protocol Stack

2.4.1 Application Layer

The Application Layer ensures reliability and low erasure rate over the airlink. It provides a fragmentation mechanism for signaling messages, along with reliable

and best effort delivery services.

The combination of RLP, and TCP layers deliver an extremely low frame error rate,which is comparable with most landline data systems today.

The RLP protocol reduces the amount of signaling due to NAK-based scheme. It provides more efficient retransmission mechanism, thus increasing the robustness

of the 1xEV-DO protocol stack. With the help of Location Update Protocol it provides seamless packet transport

service to the user through PDSN selection and handover.

2.4.2 Stream Layer

The stream layer tags all the information that is transmitted over the air link, whichincludes user traffic as well as signaling traffic.

It maps the various applications and multiplexes the streams for one Mobile. 2.4.3 Session Layer

The Session Layer protocols provide a support system for the lower layers in theprotocol stack.

It looks after the negotiation of a set of protocols and their configurations forcommunication between the Mobile and the access network.

It manages the session control like beginning the session and closing the session,resulting in efficient use of spectrum.


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2.4.4 Connection Layer

Connection layer efficiently manages the 1xEV-DO air link, reserve resources andprioritizes each users traffic.

It supports initial network acquisition.

It takes care of the air link connection establishment and maintenance.

It takes care of prioritization and packet encapsulation.

2.4.5 Security Layer

The Security Layer ensures security of the connection between the Mobile and theAccess Network.

It provides the procedures followed by the Access Network and the Mobile toexchange security keys for authentication and encryption.

It provides the procedures followed by the Access Network and the Mobile forauthenticating traffic.

It provides the procedures followed by the Access Network and the Mobile forencrypting traffic.

2.4.6 MAC LayerThe Medium Access Control layer defines the procedures used to receive and transmitover the Physical Layer.

This layer defines the rules for control channel supervision. It governs the transmission by the access network and subsequent reception.

It specifies the rules for sending messages on the access channel by the Mobile.

It enables the system to send users data packets at optimal efficiency, by utilizingvariable and fixed transmission rates and ARQ interlacing.

This layer also adds the Access Terminal address to transmitted protocols.

2.4.7 Physical Layer

The Physical layer provides the channel structure for forward link and reverse link. It defines the different modulation techniques.

It provides the encoding specifications for forward and reverse link.

2.5 CharacteristicsThis section covers the key characteristics of 1xEV-DO technology.

2.5.1 Throughputs

2.5.1.1 Forward Link Throughput

Forward link data rates range from 38.4 kbps to 2.457 Mbps.

Average forward link throughput1 for a Cell with 3 sectors and users distributed uniformlyacross the coverage area is claimed to be as in Table 3.

1The throughput mentioned does not assume transmit diversity at the cell site


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Table 3: Forward Link Throughput2

EnvironmentAntenna(Receiver)

Throughput(Mbps/Cell)

Single 3.1Pedestrian

Dual 4.0

Single 1.3Low Speed Mobile

Dual 2.5

Single 2.0High Speed Mobile

Dual 3.1

Figure 5 below shows a comparison of average forward link throughputs achieved bydifferent technologies in live commercial networks.

Average Forward Link Throughput Comparison

19.36

75.95 85.01109.69

742.1

0

100

200

300

400

500

600

700

800

GPRS AT&T

EricssonT68

1x Verizon LG VX1 1x Verizon Sierra

Wireless Aircard

1x KTF LG KH5000 1xEV-DO KTF LG

KH5000

Th

roughput(kbps)

Figure 5: Average Forward Link Throughput Comparison3

2.5.1.2 Reverse Link Throughput

Reverse Link data rate ranges from 9.6 kbps to 153.6 kbps/sector.

Reverse link average throughput is about 600 kbps/cell.

2Source: Qualcomm

3Source: Qualcomm


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Figure 6 below shows a comparison of average reverse link throughputs achieved bydifferent technologies in live commercial networks.

Figure 6: Reverse Link Throughput Comparison

2.5.2 Handoff to 1x

The 1xEV-DO allows a mobile to do a handoff to 1x when it receives a page for anincoming voice call. Since the mobile monitors the 1x Forward Common Channelperiodically, it is able to receive the page for the voice service instance. In this scenario,the mobile can be configured to

Continue the data call on the 1x system Abandon the 1xEV-DO data service instance, handoff to the 1x system, and

continue with voice only.

2.5.3 Receive Diversity

Various 1xEV-DO compatible devices are available in the market which use receivediversity to increase the overall received data rates. Receive diversity uses more than

one antenna at the receive terminal with which it can receive two or more uncorrelatedsignal. This leads to more security from fading. If one signal fades then it is possible toreceive a signal of good strength from the other antenna. By using this technique onecan increase the received data rate.


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3 Physical LayerThis section covers the 1xEV-DO physical layer in greater detail.

3.1 Forward linkForward channel structure for 1xEV-DO system is shown in the Figure 7.

Figure 7: Forward Channel Structure

As we can see in the above figure, the forward link consists of the following channels:

Pilot Channel

Medium Access Control (MAC) Channel

Traffic Channel

Control Channel

In addition, the MAC channel has three sub channels:

Reverse Activity (RA) Channel

Data Rate Control (DRC) Lock Channel

Reverse Power Control (RPC) Channel

3.1.1 Forward Link Channel Structure

The access network transmits the following forward link channels at full power in time-

multiplexed fashion. At a fixed position in every physical layer slot, these channels aretransmitted:

Pilot Channel: The pilot channel carries all 0s (no upper layer information). Since theinformation content, as well as the timing of the pilot channel, is known to the accessterminals, it simplifies the detection of the channel and helps access terminals acquirethe system quickly. It also helps with timing and synchronization. The pilot channel alsoprovides quick channel estimation to the access terminals for best serving sectorselection process.


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Medium Access Control: As the name suggests, this channel carries MAC layerrelated information such as:

Reverse activity: This indicator (one bit per slot) informs all the access terminals in asector about the level of activity in the reverse link for a specific sector. This isbroadcast information, not user-specific information.

Reverse power control: This indicator is not broadcast information but it is specific toevery active user in a sector. It indicates to the active Access Terminals whether toincrease or decrease the transmit power, thus controlling the reverse linkinterference of the sector.

The reverse activity and reverse power control channels of all active terminals arecode combined within the MAC time period using a 64-ary Walsh code.

Control Channel: This channel carries the overhead (broadcast) information, such assector parameters message, as well as user specific control information, such as trafficchannel assignment message.

Traffic Channel: As the name suggests, this channel carries user traffic at various rates,

ranging from 38.4 Kbps to 2.45Mbps.

The forward channel is time division multiplexed as shown in Figure 8. Forward channelpackets are 26.66 ms in length and are aligned to PN rolls with zero offset PNsequences. It consists of 16 slots, each of 1.67 ms duration. Traffic channel modulationsymbols are transmitted on all the 16-ary Walsh channels. One frame is divided into twohalf frames each consisting of 8 slots.

Time Division Multiplexing (TDM) of Forward Channel

1 time slot = 1.67 ms = 2048 chips.

Channels are transmitted at 100% sector power, except when idle. Full powertransmission of pilot bursts results in greater accuracy of detection. This has anadvantage over 1x where the pilot channel uses less power.

Data portion is used for both traffic and control. Control channel packets are transmitted at least once every 256 slots.


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Figure 8: TDM Channel Structure

In the forward link, there are two types of slots:

Active Slot: When Access Network has either control information or user traffic to send,it sends this information along with MAC and Pilot Channel in a time-multiplexed fashion.

Idle Slot: When Access Network does not have control information or user traffic to

send, it still sends Pilot and MAC Channels in their given time at full power and does nottransmit control/traffic information.

Paging/Control Channel Slot StructureDue to the nature of 1xEV-DO, the mobile station/access terminal monitors both the IS-2000 paging and 1XEV-DO control channels in slotted mode operation.

The 1XEV-DO control channel cycle is 256 slots and each slot is 1.67 ms in duration.1XEV-DO defines a constant that represents the number of control channel cyclesforming the sleep cycle to be NIDPSleep = 12 cycles. In effect, the sleep cycle is 256 x1.67 x 12 = 5120 ms = 5.12 seconds. 1XEV-DO also defines a function to allow anaccess terminal to determine which slot during the sleep cycle it needs to monitor for

pages.

The monitoring of slots on IS-2000 and 1XEV-DO systems for an access terminal maycollide with a low probability value. If there is a collision, then the access terminal canrequest the 1XEV-DO system to assign a different slot that it can monitor. This way theaccess terminal is able to monitor both IS-2000 and 1XEV-DO systems at the same time(in time multiplexed fashion).


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3.2 Reverse Link

Figure 9: Reverse Link Structure

In contrast to the forward link of 1XEV-DO, which has very little similarity with IS-2000system, the reverse link of 1XEV-DO system as shown in Figure 9, is quite similar to thereverse link of IS-2000.

1XEV-DO reverse link characteristics:

Power control and soft handoff supported

BPSK modulation on I & Q carrier to reduce peak to average ratio Distinct user PN sequence for source ID

Data rates from 9.6 to 153.6 Kbps

Transmits pilot and data channels

3.2.1 Reverse Link Channel Structure

In the reverse direction (access terminal to the access network), if the access terminal isnot on the traffic channel (connected), it uses access channel to access the system. Theaccess and traffic channels are code-multiplexed, where one or more channels areWalsh-spread simultaneously.

Access Channel Mode

In access channel mode, the access terminal is idle and transmits pilot and datachannels. The pilot channel is transmitted for preamble purposes as well as for timesynchronization. The data channel carries any common channel control messages fromaccess terminal when access terminal is not in connected state (does not have adedicated channel). While transmitting data channels, the access terminal also transmitspilot channels continuously.


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Access Channel StructureThe access channel has two component channels: pilot and data. The pilot channel ispurely for time synchronization for the receiver and so it does not have any realinformation bits. Since all 0s are sent on the pilot channel, there is no need for dataprotection. However, it is orthogonal spread with W0 in order to send it simultaneouslywith the data channel.

The data channel is transmitted at the fixed rate of 9.6 Kbps. It is appropriately codedusing turbo coding (coding rate of ) block interleaving and repetition, followed byorthogonal spreading using 4-bit Walsh code W2. Finally, the relative gain (relative topilot channel) is applied before both the pilot and data channels are applied accesschannel specific long PN sequence.

Traffic Channel ModeIn the traffic channel mode, the access terminal is in the connected state and transmitsthe following channels: Pilot channel: Again, the purpose of pilot channel transmission is similar as above.

It provides time synchronization to the receiver and enables coherent demodulationby the receiver.

Medium access channel: MAC has two sub channelso RRIchannel: The access terminal transmits the reverse rate indicator (RRI)

to notify the receiver of the rate of transmission. This way, the receiver doesnot have to execute any rate matching algorithms.

o DRC channel: On this channel the access terminal sends the data ratecontrol (DRC) information, which is the requested forward data rate from aselected sector.

ACK channel: The access terminal performs a physical layer acknowledgmentprocedure and sends ACK (acknowledgment) or NAK (negative acknowledgment) foreach physical layer slot received.

Data channel: The data channel in traffic channel mode carries both the user trafficand dedicated control messages. The data rate of this channel varies from 9.6 to153.6 Kbps.

Reverse Traffic Channel StructureThe long PN sequence is generated using a user specific long code mask, which in turn,is generated using assigned UATI. On the pilot channel, the reverse rate indicator bitsare time-multiplexed with the pilot bits and they are spread using 16 bit Walsh code W0.The ACK channel is protected with repetition followed by spreading with 8-bit Walshcode W4. The data rate control (DRC) bits are also encoded and repeated for properdata protection. These bits are spread using 16-bit Walsh cover W8. The ACK, DRC anddata channels are applied appropriate gain relative to the pilot channel and then are

quadrature spread using a user specific long code. This completes the physical layerbase-band processing of the reverse traffic channel.

Data Rate Control (DRC)The data rate control (DRC) channel in the reverse traffic channel is used by the accessterminal to indicate to the access network the selected serving sector and the requesteddata rate on the forward traffic channel. The access terminal predicts the carrier-interference value for each sector in the active set and selects the sector with thehighest carrier-interference value. Then it decides the best rate that can be supported by


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the predicted carrier-interference value. It reports both the best rate and best sectorinformation to the access network. The access terminal updates the best sectorinformation often and reports the best sector and rate on the DRC channel. The accessterminal maintains the active set containing all the sectors that can transmit to theaccess terminal. With each sector, a DRC cover (an 8-bit orthogonal code) isassociated. This association is established at the connection setup time and it is updated

every time a new sector is added to the active set.

4 Network

4.1 Impact of 1xEV-DO on Radio Access Network

A 1xEV-DO system can coexist with any voice technology and is optimized for packetdata services using flexible architecture based on standard Internet Protocols (IP). Byusing voice and data on separate dedicated carriers, the 1xEV-DO overlay solution thewireless systems can be optimized to provide the higher traffic capacities without

negatively impacting voice service and performance.

The hardware/software changes required in the existing network are:

An additional 1xEV-DO channel card in Base Station. Software upgradation.

1xEV-DO radio controller.

Element Manager for 1xEV-DO.

4.2 Chipset

4.2.1 CSM5500 Chipset

QUALCOMMs CSM5500 chipset is a multi-mode digital baseband modem compliantwith 1xEV-DO. Each CSM5500 chipset can operate in one of three modes: modulator,demodulator and turbo decoder.

Designed exclusively for maximum data throughput, the CSM5500 chipset supports datarates that exceed data performance provided by CDMA2000 1X, providing up to 2.4Megabits per second (Mbps) peak data rates while maintaining compatibility withexisting cdmaOne and CDMA2000 1X networks. The CSM5500 chipset, whenimplemented in QUALCOMMs current 1xEV-DO modem architecture, provides supportfor three sectors with up to 32 users per sector.

CSM5500 chipset-based 1xEV-DO access is expected to enable a whole newgeneration of high-speed data applications such as streaming video, wireless broadcastservices, and other multimedia applications.

4.2.2 CSM6800 Chipset

QUALCOMMs CSM6800 chipset is designed to deliver a higher level of integration toinfrastructure equipment manufacturers for their 1xEV-DO base station products.Supporting 1xEV-DO Revision A and backward compatible with 1xEV-DO Revision 0,the CSM6800 solution supports 192 forward-link and reverse-link channels and four-way


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receive diversity. The increased user capacity that the CSM6800 solution providesallows infrastructure equipment manufacturers and network operators to cost-effectivelyupgrade their 1xEV-DO equipment to provide substantially higher network capacityimprovements and equipment space savings.

4.2.2.1 Benefits

Enables cost-effective 1xEV-DO equipment upgrades to provide substantiallyhigher network capacity improvements and equipment space savings.

Increased levels of integration enable significant chip count and equipment sizereduction.

Higher data throughput and improved Quality of Service enhance the end user'smultimedia experience.

4.2.2.2 Key Functionality

Single-chip solution delivers significant chip count and form factor reduction.

3.1 Mbps forward link peak rate, 1.2 Mbps reverse link peak rate.

Supports 1xEV-DO Revision A and is backward compatible with 1xEV-DO

Revision 0. Support for 192 forward-link and reverse-link channels and 4-way receive

diversity.

4.3 Add on Cards in BTS

4.3.1 Data Only Module (DOM)

The DOM is a 1xEV-DO module added to the Metro Cell BTS CEM shelf to provide1xEV-DO modem capability. The DOM transmits and receives baseband data to/fromthe digital control group (DCG) in the forward direction.

The DOM performs all the encoding/decoding of the IP packets to provide backhaul datathat is transported to the data-only radio network controller (DO-RNC) over the separatedata-only (DO) network. One DOM supports up to a three sector, one 1.25 MHz carrierBTS. Additional DOMs need to be added for each additional 1xEV-DO carrier.

The data only radio network controller (DO-RNC) is at the core of the 1xEV-DO network.It forms part of the access network together with the Metro Cell BTS and the IP backhaulnetwork. It performs many of the same functions normally carried out by the base stationcontroller (BSC) in an IS-95 or IS-2000 (CDMA2000 1X) network. The DO-RNC isfrequency independent and can control BTSs that are operating on either 800 MHz or1900 MHz or a combination thereof.

4.3.2 Data Only EMS

The DO-EMS consists of both hardware (the server) and software (the client) andprovides OA&M capability and controls the operation, administration, maintenance andprovisioning (OAMP) operations for the 1xEV-DO radio access network (RAN).Some of the features of the DO-EMS are:

Collecting, reporting, and managing alarms associated with the DO-RNC andDOM.


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Collecting and storing OMs from the DO-RNC and DOM.Storing, scheduling, and distributing software downloads to the DO-RNC and

DOM.Administering and managing the neighbor list for neighbor list for 1xEV-DO carrier-sectors, including tools for reciprocal neighbor list checking

4.4 Access Network AAA ServerThe access network authorization, authentication and accounting (AN-AAA) server is acentral node, connected to the DO-RNC using the A12 interface. The purpose of the AN-AAA server is to perform terminal authentication at the beginning of a 1xEV-DO session.Once terminal authentication is accomplished, multiple air link connections can be set upand released without having to re-authenticate.

As 1xEV-DO access network does not include the MTX, it cannot use the MTX foraccess authentication procedures. To support access authentication procedures, 1xEV-DO define and use an AAA server in the access network. The AN-AAA server is anoptional requirement (as specified in IS-878)

Dependant on whether operators wish to deploy an AN-AAA server for device/terminalauthentication or not. In either case, user level authentication is performed at the PDSN-AAA server. If operators do not deploy an AN-AAA, they may use the existing AAARADIUS server currently used in the 1X network

4.5 Network Rollout with 1xEV-DO and CDMA2000 1X

For the operator who wishes to deploy both 1xEV-DO and CDMA2000 1X services, theBSC 1120 together with the ANC 1120 is installed with a choice of either the RBScompact or indoor RBS

A typical deployment may start with complete 1X coverage and additional 1xEV-DOoverlays for hot spot coverage in data intensive areas such as city centers, airports andcongress areas. The operator deploys the Radio Base Station with 1X channel cardsand BSC for the 1X coverage and complements with 1xEV-DO channel cards in RadioBase Stations at hot spots for the 1xEV-DO services. The number of 1X and 1xEV-DOcarriers supported may be different as well as the geographical coverage and theAccess Network controller and BSC can optimally placed on different sites with differentcapacity.

The RBS family should allow the operator to be flexible in the number of carriers utilizedfor 1xEV-DO and for CDMA2000 1X.

5 Handset

5.1 ChipsetTable 4 lists the features and abilities of some of the Qualcomm chipsets. It may pleasebe noted that MSM5105 is a CDMA2000 1x chipset and MSM5500 is a 1xEV-DOcompatible chipset. MSM6500 and MSM6550 chipsets are also 1xEV-DO compatiblechipsets but they are not yet in production.


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Though MSM5500 is a 1xEV-DO compatible chipset it lacks the support of Qtv Decoder,Qcamcorder encoder and Qvideophone, which are made by Qualcomm to runapplications like video conferencing, Video on demand etc. on the mobile. However itmay please be noted that MSM5500 is being used in Korea where these services arebeing provided.

Qtv DecoderThe Qtv decoder is a feature-rich software video decoder that enables mobile devices tostream, download and play back multimedia content. The Qtv solution has beenintegrated and optimized for MSM6xxx chipset solution platform, ensuring highperformance for a better user video experience. The Qtv solution is the heart of wirelessvideo applications, including streaming video-on-demand (VOD); streaming audio-on-demand (AOD); mobile viewing of real-time content (live cameras); and videomessaging.

Qcamcorder EncoderThe Qcamcorder encoder is a real-time video encoding solution that enables mobiledevices to record video and audio using their mobile phone. Mobile users can record

video, save the file in memory, and then share their experience with friends by sending itas a video message.

QvideophoneThe Qvideophone solution is a two-way video conferencing solution that has beentailored to 3G networks such as CDMA2000 1x 1xEV-DO and WCDMA/UMTS. Userscan perform real-time, mobile video-telephony calls to other mobile users to "see" theperson with whom they are communicating. The Qvideophone solution providesmanufacturers and operators with a high-performance, fully integratedvideoconferencing solution based on industry standards, which can meet the growingenterprise and consumer demand for two-way video communication worldwide.

5.2 ModelsTable 5 and Table 6 list some of the 1xEV-DO compatible mobiles and data cards andtheir manufacturers. Features and snapshots of the listed Mobiles and data cards can befound in Appendix A.

Table 5: 1xEV-DO Compatible Mobiles

Vendor Mobile Model

LG-KV1100 (CYON)

LG-KV1300/LG-SV130LG

LG-SV110 (CYON)

MITS M400

SCH-E100

SCH-E110

Samsung

SCH-E120


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SCH-E130

SCH-E135

SCH-E140

SCH-E150

SCH-E160

SCH-E170

SCH-E250/SPH-E2500

SCH-V300

SCH-V310

SCH-V350

SPH-E1000

SPH-E1000

SPH-E2000

SPH-E1700

SPH-V3000

W11KKyocera

E2000

MS-100

MS-150Motorola

V740 (Appeal TT800)

PG-S1200 (Curitel)Hyundai

PS-E100 (Curitel)

KTF E2000Others

Hitachi W11H

Table 6: 1xEV-DO Compatible Data Cards

Vendor Data Card

Kyocera W01K

DotSurfer 6000Gtran

DotSurfer 6210

Others Sierra Wireless PC5220


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Some of the features that the 1xEV-DO compatible mobiles support are listed below Colored Main and External LCD Screens

Camera

GPS capability

BREW

Polyringer

IrDA

5.3 Testing of MobilesThe objective of the test procedure is to demonstrate that mobile should satisfy theminimum criteria for compliance with the cdma2000 high rate packet data systems. Thissection lists some of the test cases with which mobiles have to be compliant.

Default Signaling Application TestsThese test cases include minimum requirements for the Default Signaling NetworkProtocol (SNP), and the Default Signaling Link Protocol (SLP). Some of the significanttest cases are:

Reliable Delivery SLP-D Packet Transmission Retransmission of Unacknowledged Reliable-Delivery SLP-D Packet

Successful Reassembly of SLP-F Packets Sent on the Access Channel

Successful Reassembly of SLP-F Packets Sent on the traffic

Reliable-Delivery SLP-D Packet Acknowledgement

Default Packet Application TestsThese include tests for the Radio Link Protocol (RLP), Location Update Protocol, andFlow Control Protocol. The following are some of the test cases in the group.

Basic File Transfer Test RLP Synchronization Loss Detection Test

Location Request Message Response

RLP Initialization Test

Stream Layer TestsThese include tests for the Default Stream Protocol. The following are some of thesignificant test cases in this category.

Stream Layer Header test

Configuration Request Message Response Test

Session Layer TestsThese include tests for the Default Session Management Protocol, Default AddressManagement Protocol and Default Session Configuration Protocol. The following aresome of the important cases in this group.

KeepAlive Request Message Response test

Session Close Message Response Test

Connection Layer TestsThis describes the tests for the following:

Default Air-Link Management Protocol

Default Initialization State Protocol

Default Idle State Protocol


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Default Connected State Protocol

Default Route Update Protocol

Default Packet Consolidation Protocol

Overhead Messages Protocol

Security Layer TestsThis section includes tests for the following

DH Key Exchange Protocol and SHA-1 Authentication Protocol

MAC Layer TestsThis section includes tests for the following

Control Channel MAC Protocol

Access Channel MAC Protocol Forward Traffic Channel MAC Protocol Reverse Traffic Channel MAC Protocol.

In addition to the cases pertaining to the protocol layers the test cases for handoff,receiver and transmitter performance are the other important categories of tests.

6 Applications and ServicesSome of the services and applications require mobile to run the applications or functionas a modem.

6.1 Push to Talk

Figure 10: Push to Talk

The PTT Service enables subscribers to conduct one-to-one or one-to-many instantvoice sessions as shown in Figure 10, using a special client on the Mobile Station. Aspecial indication on screen allows a participant in a PTT call to accept information aboutwhoever is talking at the moment. The user can select target person/group by scrollingon the handset through the address book, using a GUI that includes presence status(Online, Do not disturb, Page me and Offline).


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Since PTT uses data sessions to refresh the status, 1xEV-DOs Always On experiencewill allow more users to stay connected using this service.

6.2 Location Based ServicesLocation-based Services, provides a mobile device location "fix," often tied into mappingor direction information. Many commercial 3G services use A-GPS (assisted-globalpositioning service) to provide highly accurate positioning information to mobile phonesand other mobile devices. GPS support in the Qualcomms 1xEV-DO capable chipsetsallows accurate position determination of mobile users. Good position accuracy enablesService Provider to provide a plethora of services, some of which have been describedbelow

Emergency and Safety services: A distressed user calling to an emergency Serviceslike 100 etc can be located and provided assistance.

Navigation: The user is provided with street level details and navigational help to reachhis destination based on his current location. (see Figure 11)

Figure 11: Navigation Service

Figure 12: Nearest X and Where r u location based services

Nearest X: It provides the user with the location and/or directions for anutility/entertainment outlet, which is nearest to his current location. Here X could beATM, petrol pump, taxi stand, cinema hall, restaurant etc. (seeFigure 12).


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Where r u: Using this service a subscriber can view the location of a familymember/friend on the Mobile screen in form of a map or directions. (seeFigure 12).

6.3 Video

Figure 13: Video Streaming

The possibility to watch a video or moving image on a mobile phone as shown in Figure13, is something that has been envisioned and attempted for a long time.

There are two main types of mobile video: downloadable content vs. streaming content.Downloadable videos are short clips stored in the memory of the phone. Streamingcontent works more like a TV the phone works as a display unit, but no information isstored in the memory, making streaming great technology for longer content. Mobilevideo distribution services allow mobile users to either stream or download video contentto their mobile devices. The main difference between download and streaming is that thelatter allows transferred data to be processed as a steady and continuous stream by astreaming multimedia application and displayed before the entire file has beentransmitted.

6.4 Instant Multi-Media

Instant Multi Media (IMM) as shown in Figure 14 is an exciting new application that isattractive to a wide variety of users and is expected to generate new revenue streamsfor the operator. It brings efficient multi-media conferencing capabilities to 1xEV-DOnetworks. Any number of Users can join a conference and share audio, video and other

media like Instant Messaging. IMM is unique in that each media stream is independent:for example, both audio and video can stream from one User, or alternatively video canstream from one user, while audio can stream from another.

In a troubleshooting scenario, a Field Worker can transmit an IMM video stream to themain office while simultaneously receiving instructions from the main office over the IMMaudio stream. In social situations, friends can share video and audio with each other bysimply pressing a button.


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Figure 14: Instant Multi-Media

IMM includes Peer-to-peer messaging applications such as E-mail

IM (Instant Messaging): With the Instant Messenger on mobile, a wide spectrum ofapplications can be provided using IM as the channel for content delivery andinteraction from the user. IM is the next generation and logical extension to SMS.Just like PTT it also has the concept of buddy list and their availability details. Withthe Instant Messenger on mobile, a wide spectrum of applications can be providedusing IM as the channel for content delivery and interaction from the user.

Video Conferencing: It is a person-to-person communication service that usesvisual as well as voice data. It enables a real-time two-way stream of video andaudio signals between two mobile devices or a mobile device and a fixedvideophone.

MMS (Multimedia Messaging Services): One of the most recent developments inmobile messaging is known as multimedia messaging service (MMS). Just as the

traditional short message service (SMS), multimedia messaging provides automaticand immediate delivery of personal messages. Unlike the SMS however, MMSallows mobile phone users to enhance their messages by incorporating sound,images, and other rich content, transforming it into a personalized visual and audiomessage.

7 Comparison1xEV-DO technology is made such that it remains compatible with the 1x/IS-95 B. Thereare a lot of similarities and differences between the CDMA 1x and 1x 1xEV-DO. Beloware listed the similarities:

The Link Budgets for 1xEV-DO is same as with 1X/IS-95. This permits the reuse ofexisting 1X/IS-95 network plans.

1xEV-DO uses same waveform at the RF for communication. Hence 1xEV-DO canuse 1x system cell site antennas.

1xEV-DO uses same 1.25 MHz bandwidth as used by 1x system.

Reverse link of both CDMA2000 1x and 1xEV-DO use code division multiplexing. Closed and Open loop power control dictate mean output power on Reverse link.


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Dissimilarity from 1x/ IS-95 B:

1xEV-DO is optimized for the data. Unlike CDMA2000 it does not support voice anddata on the same carrier.

There is no power control in the forward link of 1xEV-DO. EV-DO spectral efficiency is higher than that of 1x system.

Coding gain is high in 1xEV-DO as it employs turbo codes, which are more efficientthan convolution codes.

1xEV-DO uses time division multiplexing on the forward link while 1x used Codedivision multiplexing on the forward link.

1xEV-DO uses variable data rate according to varying channel condition whileCDMA adapt power according to varying channel condition.

1xEV-DO gives user always on experience. Which is not possible in case of 1xnetwork. In 1xEV-DO PPP state can be retained for longer duration of time.

Because 1xEV-DO is optimized for data so it takes lesser time to enter in to activestate from the dormant state in comparison to 1x network.

8 Summary1xEV-DO is a promising technology offering high data rates and high capacity in thesame spectrum as CDMA2000. The technology infrastructure and access terminals arecommercially available and deployed in a number of markets. It enables a number ofcompelling services requiring higher data rates, which will increase data ARPU ofoperators.

Some areas, which need further study are discussed below:

Comparison of 1xEV-DO with other high rate data technologies like Wi-Max and1xEV-DV. Wi-Max and 1xEV-DV though not available today promise much higherdata rates than 1xEV-DO.

Implementation of broadcast services that enable delivery of TV Channels andcricket matches. For any broadcast service to be successful the broadcastshould be done at the physical layer itself and the broadcast addresses shouldbe easily configurable over the air so that a user can subscribe and unsubscribeto the service.

Evolution path of 1xEV-DO


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