1. March 2009
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Preliminary Proposal for a Multi-Regional Sub-GHz PHY for g]
Date Submitted: [ 01 March, 2009]
Source: [Khanh Tuan Le] Company [Texas Instruments]
[Per Torstein Roine] Company [Texas Instruments]
Address [Gaustadalleen 21, 0349 Oslo, Norway]
Voice: [ ],
Re: []
Abstract: [Preliminary proposal for a multi-regional sub-GHz PHY for g.]
Purpose: [Technical proposal. Presented to the g SUN Task Group for consideration.]
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
Khanh Tuan Le

2. Preliminary Proposal for a Multi-Regional Sub-GHz PHY for 802.15.4g
March 2009
Preliminary Proposal for a Multi-Regional Sub-GHz PHY for g
IEEE 802 Plenary Meeting
11th March 2009, Vancouver, BC
Khanh Tuan Le
Khanh Tuan Le

3. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
OVERVIEW
Overall Considerations
Proposal Summary
GFSK and Frequency Hopping
Proposal Details for Europe
Proposal Details for the US
Suitability for Other Emerging Frequency Bands
FEC, Whitening and Packet Format
Discussion
Khanh Tuan Le
<author>, <company>

4. Overall Considerations (1)
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Overall Considerations (1)
Focus on user requirements, available frequency spectrum and applicable regulations for US and Europe
Suitable technology for appropriate frequency bands in other regions, e.g. China and Japan
Full utilization of allowed maximum output power by regional regulations possible
Long communication range can be supported
Adaptive to application needs
Reliable networks using relatively simple modulation schemes, e.g. FSK, GFSK, MSK
Khanh Tuan Le
<author>, <company>

5. Overall Considerations (2)
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Overall Considerations (2)
2.4 GHz PHY options available (e.g )
Sub-GHz technology are beneficial in many metering applications
Power
Range
Spectral efficiency increasingly more important
Need for higher data rates
Strong drive for standardization
Technology requirements- Power optimized and cost efficient semiconductor solutions, protocol SW
Khanh Tuan Le
<author>, <company>

6. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Proposal Summary
License exempt bands in the US and Europe
US: MHz
Multiple channels, Frequency Hopping
Max output power: 1W (30 dBm), dynamic power control
Europe: MHz
Multiple channels, Frequency Agility and LBT
Max output power: 500 mW (27 dBm) and 25 mW (14 dBm), dynamic power control
Modulation format: 2-GFSK and 4-GFSK
Data rates: 50/100/200/400 kbps
Suitable for appropriate frequency bands in other regions
Khanh Tuan Le
<author>, <company>

7. Gaussian Frequency Shift Keying (N-GFSK)
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Gaussian Frequency Shift Keying (N-GFSK)
FSK derivative- Constant amplitude modulation
Gaussian shaping provides better spectrum efficiency.
2-GFSK
1 bit/symbol
Defined for d (BT=0.5, h=1)
4-GFSK
2 bit/symbol
GFSK can be efficiently implemented on silicon radios and is widely used today.
Khanh Tuan Le
<author>, <company>

8. Frequency Hopping Spread Spectrum
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Frequency Hopping Spread Spectrum
Required by regulations for high transmit power levels
Can be used for co-existence of multiple networks
Can enable high aggregate throughput
Inherent frequency diversity mechanism
Well known and proven technique
Required performance can be effectively achieved by semiconductor radio devices today
Khanh Tuan Le
<author>, <company>

9. 863-870 MHz ISM Band in Europe (1)
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MHz ISM Band in Europe (1)
Regulations in Europe are continuously being revised.
Khanh Tuan Le
<author>, <company>

10. 863-870 MHz ISM Band in Europe (2)
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MHz ISM Band in Europe (2)
ETSI
Modulation and (programmable) data rates:
2-GFSK: 50 kbps and 100 kbps *Lower data rates are easy to support.
4-GFSK: 200 kbps and 400 kbps
Frequency band and allowed max output power:
MHz (600 kHz): 25 mW / +14 dBm
MHz (500 kHz): 25 mW / +14 dBm
MHz (250 kHz): 500 mW / +27 dBm
Dynamic power control
Frequency Agility
Flexible trade-off between communication range and data rates
Khanh Tuan Le
<author>, <company>

11. 863-870 MHz ISM Band in Europe (3)
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MHz ISM Band in Europe (3)
Frequency Range
[MHz]
# Channels
Channel Spacing
[kHz]
Modulation
Data Rate
[kbps]
Max Output Power [dBm]
(250 kHz) 1 NA
2-GFSK 50
+27
100
4-GFSK
200
(600 kHz) 3
+14 2
250
400
(500 kHz)
Khanh Tuan Le
<author>, <company>

12. 863-870 MHz ISM Band in Europe (4)
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MHz ISM Band in Europe (4)
One possible scheme with single data rate:
Data rate: 100 kbps
Modulation: 2-GFSK
Channel spacing: 250 kHz
Number of channels: 5
Channel 1: MHz, 25 mW / +14 dBm
Channel 2: MHz, 25 mW / +14 dBm
Channel 3: MHz, 25 mW / +14 dBm
Channel 4: MHz, 25 mW / +14 dBm
Channel 5: MHz, 500 mW / +27 dBm
Frequency Agility
Khanh Tuan Le
<author>, <company>

13. 863-870 MHz ISM Band in Europe (5)
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doc.: IEEE <doc#>
March 2009
MHz ISM Band in Europe (5)
Khanh Tuan Le
<author>, <company>

14. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
ISM MHz Band in US (1)
FCC Part
Modulation and (programmable) data rates:
2-GFSK: 50 kbps and 100 kbps *Lower data rates are easy to support.
4-GFSK: 200 kbps and 400 kbps
Frequency band and allowed max output power:
MHz (26 MHz): 1 W / +30 dBm (500 mW / +27 dBm)
Dynamic power control
Frequency Hopping (FH)
Flexible trade-off between communication range and data rates
Khanh Tuan Le
<author>, <company>

15. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
ISM MHz Band in US (2)
# Channels
Channel Spacing
[kHz]
Modulation
Data Rate
[kbps]
Max Output Power [dBm] 50
500
2-GFSK
+30
100
4-GFSK
200
400
Basic FH scheme can support any of the data rates in the table and facilitate max +30 dBm output power if needed.
Additional set(s) of (offset) channels could be defined to support multiple networks in the same area
The offset channels would partly overlap when the highest data rates are used
The main coexistence mechanism would still be the use of different hopping sequences
Although networks share the same frequency range, coexistence is improved by good far-away selectivity, as the networks have a high probability of large frequency spacing at any given moment in time
Multipath fading mitigation and coexistence with other networks are maximized utilizing the entire frequency band
Khanh Tuan Le
<author>, <company>

16. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Multiple FH Networks
Khanh Tuan Le
<author>, <company>

17. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Other Regions
Spectrum efficiency is important.
Similar channelization scheme and modulation formats may be applicable for the appropriate emerging frequency bands in other regions
Frequency Hopping or Frequency Agility
Japan: ARIB STD T MHz – May not be allocated for this type of applications?
China: Example in the table below
# Channels
Channel Spacing
[kHz]
Modulation
Data Rate
[kbps]
Max Output Power [dBm] N
200
2-GFSK 50
+17
4-GFSK 75
Khanh Tuan Le
<author>, <company>

18. Dynamic Link Functionality
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Dynamic Link Functionality
Idea for consideration:
Same channelization
Same channel separation
Same center frequencies
Higher data rate(s) by change in modulation format, e.g. 2-GFSK to 4-GFSK
Trade-off
Reduced link budget (range)
Shorter transmission time or more data over same time period
Khanh Tuan Le
<author>, <company>

19. Simple Low Overhead FEC Proposal
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Simple Low Overhead FEC Proposal
As support for very long packets is mandatory, a simple low-overhead FEC should be considered to improve the packet error rate
Proposal: (128,120,4) extended Hamming code
SECDED: Corrects single bit, detect double bit errors
Double bit error detection does not improve PER, but is useful for early receive termination when packet is corrupted
Can also be viewed/implemented as (127,120,3) BCH, extended by an extra parity bit
Generator polynomials: x7+x3+1 (BCH) and x+1 (extra parity)
After 15 octets of PHY data, one octet containing parity check bits (PCB) is inserted
Khanh Tuan Le
<author>, <company>

20. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Packet Format
Khanh Tuan Le
<author>, <company>

21. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Whitening Proposal
Whitening is done after FEC octet insertion
Idea:
Same LFSR polynomial is used for whitening all the time
The whitening LFSR is initialized to an unique value based on the channel number (and data rate) used for the packet
This would allow retransmissions to use different whitening for protection from packet data with poor whitening performance
Khanh Tuan Le
<author>, <company>

22. doc.: IEEE 802.15-<doc#>
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doc.: IEEE <doc#>
March 2009
Thank you!
Khanh Tuan Le
<author>, <company>