Doc.: 15-04-0461-01-004A Sub-Committee Report September 2004 Martin et alSlide 1 Project: IEEE...
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Transcript of Doc.: 15-04-0461-01-004A Sub-Committee Report September 2004 Martin et alSlide 1 Project: IEEE...
September 2004
Martin et alSlide 1
doc.: 15-04-0461-01-004A
Sub-Committee Report
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Recommendations of the Range Issue SubcommitteeDate Submitted: September 2004Source: Frederick Martin, Motorola, Inc., Colin Lanzl, Aware, Inc., Paul Gorday, Motorola, Inc., Rick
Roberts, Harris Corporation, Kai Siwiak, TimeDerivative, Inc.Contact: F. Martin, Motorola, Inc., 8000 W. Sunrise Blvd. Plantation, FL 33322Voice: +1 954-723-6395, FAX: +1 954-723-3712, E-Mail: [email protected]
Re: Range Issue Sub-Committee
Abstract: A model and basis of comparison is proposed for comparing range performance of the baseline 802.15.4 PHY layer with proposals for 802.15.4a.
Purpose: Tutorial information on capabilities of current 15.4 hardware.
Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.
September 2004
Martin et alSlide 2
doc.: 15-04-0461-01-004A
Sub-Committee Report
Sub-Committee Charter
“In response to the 802.15.4a PAR, clause 12, Scope of Proposed Project (document 15-04-0048-01-004a), this subcommittee's scope is to study the range implications of 802.15.4 devices and how we might ask the 802.15.4a proposers to show at least an enhanced range mode.”
September 2004
Martin et alSlide 3
doc.: 15-04-0461-01-004A
Sub-Committee Report
The issue
802.15.4 bands: 250 kbit/s @ 2400 MHz (worldwide)
40 kbit/s @ 900 MHz (North America)
20 kbit/s @ 868 MHz (Europe)
Power: typical 0 dBm
maximum: Regulatory max (100 mW Europe, 1 W US !!)
Antenna: not specified
Receiver sensitivity: not specified
Result: typical indoor range may be 10 to 30 m
maximum outdoor range may be several km !!!
September 2004
Martin et alSlide 4
doc.: 15-04-0461-01-004A
Sub-Committee Report
The Search for Guidance (2)
802.15.4 PAR – Purpose
[To provide a standard for ultra low complexity, ultra low cost, ultra low power consumption and low data rate wireless connectivity among inexpensive devices. The raw data rate will be high enough (maximum of 200kbs) to satisfy a set of simple needs such as interactive toys, but scaleable down to the needs of sensor and automation needs (10kbps or below) for wireless communications.
802.15.4 PAR -- Scope[This project will define the PHY and MAC specifications for low data rate wireless
connectivity with fixed, portable and moving devices with no battery or very limited battery consumption requirements typically operating in the Personal Operating Space (POS) of 10 meters …
September 2004
Martin et alSlide 5
doc.: 15-04-0461-01-004A
Sub-Committee Report
The Search for Guidance (2)
802.15.4a PAR – Scope
[This project will define an alternative PHY clause for a data communication standard with precision ranging, extended range, enhanced robustness and mobility amendment to standard 802.15.4 (18a).]
802.15.4a PAR -- Purpose
[To provide a standard for a low complexity, low cost, low power consumption alternate PHY for 802.15.4 (comparable to the goals for 802.15.4). The precision ranging capability will be accurate enough, several centimeters or more, and the range, robustness and mobility improved enough, to satisfy an evolutionary set of industrial and consumer needs for WPAN communications. The project will address the requirements to support sensor, control, logistic and peripheral networks in multiple compliant co-located systems and also coexistence (18b).]
September 2004
Martin et alSlide 6
doc.: 15-04-0461-01-004A
Sub-Committee Report
The Philosophy behind the Proposed Solution
In the spirit of the 802.15.4 PAR, compare 4A proposals with typical low cost, low power 802.15.4a implementations
Transmit Power: +6 dBm (900 MHz), 0 dBm (2400 MHz)
Receive Sensitivity: -95 dBm (900 MHz), -90 dBm (2400 MHz)
isotropic antenna
See specs for Freescale MC13192CompXs – CX1540Atmel – AT86RF210Chipcon -- CC2420
September 2004
Martin et alSlide 7
doc.: 15-04-0461-01-004A
Sub-Committee Report
Indoor Path Model Comparison
Colin Lanzl [email protected]
Kai Siwiak [email protected]
Paul Gorday [email protected]
September 2004
Martin et alSlide 8
doc.: 15-04-0461-01-004A
Sub-Committee Report
Two-Breakpoint Model with Recommended Parameters
PL(d )= 10log{[c/(4dfm)]2 [exp((dt1 /d))][1-exp((dt2/d)
2-
1]},
where:PL: pathloss, dB;d: distance between transmitter and receiver;
fm: geometric mean of transmitted frequency band;
propagation constant after first breakpoint (3.7);
propagation constant after second breakpoint (10.5);c: velocity of propagation;
dt1: first breakpoint distance from transmitter (5 meters);
dt2: second breakpoint distance from transmitter (30 meters).
September 2004
Martin et alSlide 9
doc.: 15-04-0461-01-004A
Sub-Committee Report
Loss-per-Meter Indoor Model with Recommended Parameters
• PL(d )= -10log{[c/(4pdfm)]2} + *d,
• where:
• PL: pathloss, dB;
• d: distance between transmitter and receiver;
• fm: geometric mean of transmitted frequency band;
: loss-per-meter parameter (0.60dB per meter);
• c: velocity of propagation.
September 2004
Martin et alSlide 10
doc.: 15-04-0461-01-004A
Sub-Committee Report
Comparison of Indoor Path Loss Models
September 2004
Martin et alSlide 11
doc.: 15-04-0461-01-004A
Sub-Committee Report
Path Loss References[1] K. Siwiak, A. Petroff, “A Path Link Model for Ultra Wide Band Pulse Transmissions,” Proc. IEEE Vehicular Techonlogy Conference, Spring 2001, vol. 2, pp. 1173-1175.
[2] D. Devasirvatham, et al., “Multi-Frequency Radiowave Propagation Measurements in the Portable Radio Environment,” IEEE International Conference on Communications, April 1990, vol. 4, pp. 1334-1340.
[3] K. Marquess, “Physical Model Sub-Group Discussion and Questions,” Submission to IEEE 802.15 Working Group for Wireless Personal Area Networks, Doc. IEEE 802.15/138r0, Nov. 1999.
[4] K. Siwiak, “Basic Propagation Attenuation Model Suitable for UWB and Narrow Band Signals,” IEEE P802.15 Working Group for Wireless Personal Area Networks, Doc. IEEE P802.15-04/0408r1, August 2004.
[5] D. Cassioli, et al., “The Ultra-Wide Bandwidth Indoor Channel: From Statistical Model to Simulations,” IEEE Journal on Selected Areas in Communications, vol. 20, no. 6, Aug. 2002.
[6] S. Ghassemzadeh, et al., “A Statistical Path Loss Model for In-Home UWB Channels,” IEEE Conference on Ultra Wideband Systems and Technologies, May 2002, pp. 59-64.
[7] L. Rusch, et al., “Characterization of UWB Propagation from 2 to 8 GHz in a Residential Environment,” http://www.intel.com/technology/ultrawideband/pres_tech.htm.
September 2004
Martin et alSlide 12
doc.: 15-04-0461-01-004A
Sub-Committee Report
Flat Fading Margin for 802.15.4
• Assume that both 802.15.4 PHY’s undergo flat Rayleigh fading– Chip pulse length is relatively long compared to RMS delay spread: (pulse length = 1 s at 2.4
GHz, 3.3 s at 900 MHz, 6.7 s at 868 MHz)– Simple 2.4 GHz PHY implementation (no equalizer or rake) shows multipath performance similar to flat
fading for RMS delay spreads up to 300-400 ns (doc. 337r0). 868/915 MHz PHY would tolerate more.– Diversity methods (antenna, rake, mesh network, etc.) would improve performance relative to flat
Rayleigh fading, but are not considered here.
• Rayleigh fading margin vs. desired reliability– 10 dB margin gives 90% probability of exceeding desired level– 13 dB margin gives 95% probability of exceeding desired level
• Typical PHY sensitivity (1% PER, 20-byte PSDU)– 2.4 GHz PHY: -90 dBm– 868/915 MHz PHY: -95 dBm– Typical performance is 3-5 dB better than 802.15.4 PHY spec.
September 2004
Martin et alSlide 13
doc.: 15-04-0461-01-004A
Sub-Committee Report
Baseline performance of 802.15.4
900 MHz
2400 MHz
Transmit Power (dBm) +6 0
RX Sensitivity (dBm) -95 -90
Fading Margin (dB) 10 10
Link Budget (dB) 91 80
Range (m)
(2 breakpoint model)
43 25
Range (m)
(Loss per meter model)
44 22
INP
UT
SC
AL
CU
LA
TE
D V
AL
UE
S
LINK BUDGET = TX POWER +RX SENSITIVITY – FADING MARGIN
September 2004
Martin et alSlide 14
doc.: 15-04-0461-01-004A
Sub-Committee Report
Sub-Committee Recommendations
1. Compare proposals with typical low-cost, low-power implementations of 802.15.4. See slide 6.
2. Apply either the 2 breakpoint model (slide 8) or the loss per meter model (slide 9) as a basis for comparison.
3. Adopt 10 dB as the flat fading margin for the 802.15.4 baseline per slide 12.
4. Leave to proposers the responsibility for specifying and justifying fading margin and receiver performance assumptions for their proposals.
September 2004
Martin et alSlide 15
doc.: 15-04-0461-01-004A
Sub-Committee Report
Discussion ???