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  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: GFSK PHY proposal for Smart Utility Networks Date Submitted: April 29, 2009 Source: Henk de Ruijter and Ping Xiong, Silicon Laboratories Inc. Contact: Henk de Ruijter, Silicon Laboratories Inc. Voice: +1 650 623 9155 , E-Mail: hendricus.deruijter@silabs.com Re: TG4g Call for proposals Abstract: PHY proposal towards TG4g Purpose: PHY proposal for the TG4g PHY amendment 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. Slide 1 Henk de Ruijter

  2. Overview Why GFSK Common characteristics of the proposed PHY USA specifics EU specifics Japan specifics China specifics Frequency tolerance Slide 2 Henk de Ruijter

  3. Existing meter reading PHYs • FCC part 90 • Licensed bands (mostly 450 ~ 470 MHz) • Narrow band GFSK • M-Bus (BS EN13757) • Band: 868 ~ 870 MHz • Modulation: FSK • Coding: Manchester and “3 out of 6” coding • Propriety • FSK • GFSK Slide 3 Henk de Ruijter

  4. Why GFSK? • Lower adjacent channel emission than FSK complying to local regulations • No linear amplifier needed as appose to BPSK/OQPSK • Low complexity in the modem serving low cost endpoints. • Proven technology for FHSS • Proven technology for Meter reading Slide 4 Henk de Ruijter

  5. PHY basics Modulation type: GFSK Modulation index: 0.75 BT factor: 0.5 Data rate: 40 and 100 kbps depending on local regulations (single data rate per region) Data whitening: PN9 according to 802.15.4d 64 bit preamble supporting Antenna Diversity 16 and 32 bit CRC depending on payload length Slide 5 Henk de Ruijter

  6. Data whitening and Modulation • Same as 15.4d[5] Slide 6 Henk de Ruijter

  7. Data whitening same as 15.4d[5] • Seed = “111111111” • For details see [5] Slide 7 Henk de Ruijter

  8. PHY Packet Preamble 64 bit SFD 16 bit PHR 8/16 bit PSDU max: 2048 bit • 64 bit preamble to support Antenna Diversity = 16 x Ah • 16 bit SFD to reduce false synchronization = 2DD4h • PHR = 16 bit to support long payloads • LSB of PHR controls PHR length, “0” = 7bit length, “1” = 15bit length • CRC = 32 bits to support long payloads • LSB of PHR controls CRC type: “0” = CRC16, “1” = CRC32 • When channel hoping is used: one PHY Packet per hop (slow channel hopping. Slide 8 Henk de Ruijter

  9. CRC • CRC depends on payload length • Derived from Frame Length field (PHR) • 16 bits CRC up to 127 Octets (802.15.4) • 32 bits CRC for more than 127 Octets • Supporting long packets • CRC16 (ITU-T) = 802.15.4b • CRC32 (IEEE 802.3) polynomial: • x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1 • Seed: EDB88320 Slide 9 Henk de Ruijter

  10. PSD at 100kbps Slide 10 Henk de Ruijter

  11. PSD at 40kbps Slide 11 Henk de Ruijter

  12. Per Region: Slide 12 Henk de Ruijter

  13. FCC part 15.247 • For frequency hopping systems operating in the 902-928 MHz band: if the 20 dB bandwidth of the hopping channel is less than 250 kHz, the system shall use at least 50 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 20 second period; • Max peak conducted output power for frequency hopping systems operating in the 902-928 MHz band is 1 Watt for systems employing at least 50 hopping channels. Slide 13 Henk de Ruijter

  14. EU 868MHz Band (non-specific SRD)[1] Slide 14 Henk de Ruijter

  15. Constrains FHSS in “g” Band • Sub-bands for alarms are excluded: • Max channel spacing = 100kHz • Minimum number of channels = 47 • Maximum emission at sub-band edges is -36dBm in 100kHz • Max duty cycle = 0.1% • NOTE: The duty cycle applies to the entire transmission (not at each hopping channel). • Max dwell time per channel = 400 ms • The maximum return time to a hopping channel shall be equal or less than the product of 4 x dwell and the number of hopping channels and must not exceed 20 s. • Each channel of the hopping sequence shall be occupied at least once during a period not exceeding the product of 4 x dwell time and the number of hopping channels. • In case of LBT being used for FHSS, this function shall be used at each hop channel. Slide 15 Henk de Ruijter

  16. Channel plan for EU: Note: Sub-bands for Alarm are excluded (gray frequencies) Slide 16 Henk de Ruijter

  17. China (470-510MHz): • When TX on time is no more than 5 sec then this band can be used for civilian meter reading. • ERP max = 50mW • Max frequency tolerance 100ppm • Spurious limit: -54dBm in 100kHz @ +/-2.5 CHBW - Needs confirmation Slide 17 Henk de Ruijter

  18. References • [1] ERC/REC 70-03 - Version of February 28, 2009 • [2] ETSI 300 220 - V2.2.1 (2008 04) • [3] ARIB STD T96 - v1.0 June 6, 2008 • [4] FCC Part 15 - July 10, 2008 • [5] IEEE Std 802.15.4d™-2009(April 17, 2009) • [6] Slide 18 Henk de Ruijter