1. September 18
May 2009
Project: IEEE P 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: ,
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 P 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 P
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2. Overview Why GFSK Common characteristics of the proposed PHY
September 18
May 2009
Overview
Why GFSK
Common characteristics of the proposed PHY
USA specifics
EU specifics
Japan specifics
China specifics
Frequency tolerance
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3. Existing meter reading PHYs
September 18
May 2009
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
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4. September 18
May 2009
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
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5. PHY basics Modulation type: GFSK Modulation index: 0.75 BT factor: 0.5
September 18
May 2009
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 d
64 bit preamble supporting Antenna Diversity
16 and 32 bit CRC depending on payload length
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6. Data whitening and Modulation
May 2009
Data whitening and Modulation
Same as 15.4d[5]
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7. Data whitening same as 15.4d[5]
May 2009
Data whitening same as 15.4d[5]
Seed = “ ”
For details see [5]
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8. May 2009
PHY Packet
Preamble 64 bit
SFD bit
PHR /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.
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9. CRC CRC depends on payload length
September 18
May 2009
CRC
CRC depends on payload length
Derived from Frame Length field (PHR)
16 bits CRC up to 127 Octets ( )
32 bits CRC for more than 127 Octets
Supporting long packets
CRC16 (ITU-T) = b
CRC32 (IEEE 802.3) polynomial:
x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
Seed: EDB88320
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10. September 18
May 2009
PSD at 100kbps
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11. September 18
May 2009
PSD at 40kbps
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12. Per Region: May 2009 Region Band [MHz] Pmax [dBm] Rb [kbps]
September 18
May 2009
Per Region:
Region
Band
[MHz]
Pmax
[dBm] Rb
[kbps]
Channel spacing [kHz]
Lowest freq
[kHz]
Highest freq [kHz]
Total # of channels
FHSS/AFA
USA
FCC part 15 30
100
300
902,300
927,500 85
slow channel hopping
Europe
ETSI EN 14 40
863,300
869,000 52
Japan
ARIB STD T96
0 & 10
400
955,500 11
AFA
China 17
470,400
509,600 99
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13. September 18
May 2009
FCC part
For frequency hopping systems operating in the 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 MHz band is 1 Watt for systems employing at least 50 hopping channels.
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14. EU 868MHz Band (non-specific SRD)[1]
May 2009
EU 868MHz Band (non-specific SRD)[1]
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15. Constrains FHSS in “g” Band
September 18
May 2009
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.
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16. September 18
May 2009
Channel plan for EU:
ch1
863.3
ch14
864.6
ch27
865.9
ch40
867.2
868.5
ch2
863.4
ch15
864.7
ch28
866.0
ch41
867.3
868.6
ch3
863.5
ch16
864.8
ch29
866.1
ch42
867.4
868.7
ch4
863.6
ch17
864.9
ch30
866.2
ch43
867.5
868.8
ch5
863.7
ch18
865.0
ch31
866.3
ch44
867.6
868.9
ch6
863.8
ch19
865.1
ch32
866.4
ch45
867.7
ch52
869.0
ch7
863.9
ch20
865.2
ch33
866.5
ch46
867.8
869.1
ch8
864.0
ch21
865.3
ch34
866.6
ch47
867.9
869.2
ch9
864.1
ch22
865.4
ch35
866.7
ch48
868.0
869.3
ch10
864.2
ch23
865.5
ch36
866.8
ch49
868.1
869.4
ch11
864.3
ch24
865.6
ch37
866.9
ch50
868.2
869.5
ch12
864.4
ch25
865.7
ch38
867.0
ch51
868.3
869.6
ch13
864.5
ch26
865.8
ch39
867.1
868.4
869.7
Note: Sub-bands for Alarm are excluded (gray frequencies)
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17. September 18
May 2009
China ( MHz):
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 +/-2.5 CHBW
- Needs confirmation
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18. References [1] ERC/REC 70-03 - Version of February 28, 2009
September 18
May 2009
References
[1] ERC/REC Version of February 28, 2009
[2] ETSI V2.2.1 ( )
[3] ARIB STD T96 - v1.0 June 6, 2008
[4] FCC Part 15 - July 10, 2008
[5] IEEE Std d™-2009 (April 17, 2009)
[6]
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