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Project: IEEE P802.15 WG for Wireless Personal Area Networks (WPANs)

Project: IEEE P802.15 WG for Wireless Personal Area Networks (WPANs) Submission Title: [Summary of ITRON Proposal to TG4g ] Date Submitted: [ May, 2009 ] Source: [ Daniel Popa, John Buffington ] Company: [ ITRON ] Address: [2111 N Molter Road, Liberty Lake, Washington 99019]

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Project: IEEE P802.15 WG for Wireless Personal Area Networks (WPANs)

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  1. Project: IEEE P802.15 WG for Wireless Personal Area Networks (WPANs) Submission Title: [Summary of ITRON Proposal to TG4g ] Date Submitted: [May, 2009] Source: [Daniel Popa, John Buffington] Company: [ITRON] Address:[2111 N Molter Road, Liberty Lake, Washington 99019] Voice: [+33 15835 1760, +1 800 635 5461]E-Mail: [{daniel.popa, john.buffington}@itron.com] Re: [ Response to CFP issued January 22nd 2009, document 15-09-077-00-004g ]Abstract: []Purpose: [ Proposal for consideration of inclusion into 802.15.4 PHY draft 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. <Daniel Popa, John Buffington>, <ITRON>

  2. Agenda Overview of proposal (15-09-299-00-00) PHY & MAC Recommendations Harmonization for slow/MAC FH solutions <Daniel Popa, John Buffington>, <ITRON>

  3. Outline of ITRON’s Proposal to TG4g Proposal focuses on FHSS with slow/MAC hopping for (NA/EU) bands of 902-928 MHz 2.4 GHz Channel bandwidth, channel spacing & channel assignments Extensions to PHY Header of IEEE 802.15.4-2006 for PHY transmission reliability Co-existence of different networks <Daniel Popa, John Buffington>, <ITRON>

  4. ITRON Proposal * *Source: Benjamin Rolfe & al., “Common platform for narrow band frequency hopping PHY“, Document IEEE P802.15-09-0298-00-004g, May 7, 2009. <Daniel Popa, John Buffington>, <ITRON>

  5. Proposal Features <Daniel Popa, John Buffington>, <ITRON>

  6. Physical layer (PHY) • Common slow/MAC FHSS features: PHY Layer is by default in receiving mode and should not decide on its own to transmit. All its instructions, including packets to send, should come from the MAC layer: • Activation and deactivation of the radio transceiver • Channel frequency selection • Data transmission and reception • Measure of the received input power strength, i.e., RSSI • Extensions: PHY Layer measures and gives the received input power strength RSSI value on the current listening channel, as follows • per received packet : provides instantaneous RSSI and time of reception for the MAC layer • provides some RSSI averaging features (for LQI purposes) • MAC sub-layer • MAC layer is the synchronization & hopping manager • “Slow” hoping sequence, based on slot timing • Requires some additional services from PHY Layer • PHY should provide timing to MAC sub-layer <Daniel Popa, John Buffington>, <ITRON>

  7. 802.15.4g Specification Modification • Modulation: 2-FSK / 2-GFSK: • propose 2-FSK/2-GFSK as common feature • can provide 100 kbps with adequate link margin • backward compatible with a number of existing (large) deployments of Utility Networks • low cost radio designs • optional future modulations: any “M” M-FSK, MSK, OFDM • Additional PHY definition? • Channel spacing & channel bandwidth: • channel spacing: ≤ 500 kHz @ 902-928 MHz & ≤ 1 MHz @ 2.4 GHz and as allowed by the FCC • channel bandwidth: 150 up to 400kHz @ -20 dB for 902-928 MHz & 120 kHz @ -20 dB for 2.4 GHz • Channel assignments: fixed versus variable number of channels • a lower bound threshold (on channel page) for the number of channels should be enough; it depends on number of channels available by regulation • e.g., NA/FCC: minimum 50 channels @902-928 MHz ; minimum 15 channels @2.4 GHz • imposing only a lower bound threshold allows flexible design, implementation & planning trade-offs and increases the number of co-located networks (sharing the same “floor”); more available channels means more orthogonal hopping sequences • equal probability of using a hop/frequency for 902-928 MHz <Daniel Popa, John Buffington>, <ITRON>

  8. 802.15.4g Specification Modification • Data “whitening” (scrambling): • Make this optional: requires additional processing and may not always be needed • As optional feature, it simplifies implementation of hardware if receiver can tolerate long run lengths or 0’s and 1’s • Do we really need it with encryption (if encryption scrambles the MAC-PDU)? • Data bit rate: • Allow multiple bit rates: 20/50/100 kbps: backward compatibility for any existing systems <Daniel Popa, John Buffington>, <ITRON>

  9. 802.15.4g Specification Modification(cont’d) • PHY Protocol Data Unit (PPDU) • MTU (Maximum Transmission Unit) Payload • We would like to see 1024 Bytes but can migrate to 2048 • Have concerns regarding error rate with larger packet sizes • Add some extensions to PHY header: • FEC or complementing bits for PHY header: • complementing bits (“light” FCS-like) for PHY header fields • optional header FEC: robustness of PHY header transmission over noisy floors with potential important gain in system sensitivity; yet,FEC for MAC-PDU can be useless effort if PHY header is frequently “damaged” • NID (Network ID): • fast response to attempts of joining cluster administrated by different utility providers during the Discovery Phase ; • efficiently tackles the cross-over traffic interferences when clock drifting makes that Rx/Tx from adjacent clusters (and thus with orthogonal hopping sequences) “hop” on identical channel within some time-slots <Daniel Popa, John Buffington>, <ITRON>

  10. Attempt of joining a cluster administrated by a different (utility) provider Cluster/Network ID_A Cluster/Network ID_B “Flooding” Discovery/other messages inside the right private network “Flooding” Discovery/other messages towards a wrong private network <Daniel Popa, John Buffington>, <ITRON>

  11. Extensions to PPDU PHY header: complementing bits (A) / FEC for reliability (B) A) Octets min 4 2/4 4 variable Bits 32 16/32 4 2 10 4 2 10 variable Field Preamble/SYNCH SFD NID Reserved Frame length NID-C Reserved-C Frame length-C PSDU (MAC PPDU + optional FEC) SHR PHR PHY payload B) Octets min 4 2/4 2 2 variable Bits 32 16/32 4 2 10 16 variable Field Preamble/SYNCH SFD NID Reserved Frame length Optional FEC PSDU (MAC PPDU + optional FEC) SHR PHR PHY payload PHR: length w/ complementary bits: (4+2+10) x 2 = 4 Octets PHR: length w/ FEC : (4+2+10) +16 = 4 Octets <Daniel Popa, John Buffington>, <ITRON>

  12. 802.15.4g Specification Modification(cont’d) • Forward Error Correction (FEC) for PPDU payload • Optional feature to protect data against interferences/noise • Block coding FEC with an interleaved Reed-Solomon (38,28) coding • Allow support for multi-MAC protocols • Support multiple timing and resource sharing schemes: this allows existing low cost systems and future evolution for more complex systems to take advantage of the specification while driving radio costs down. • Transmit power: • Variable transmit power levels to be used, within regulatory limitations, to ensure proper balance between interferences and required link margin <Daniel Popa, John Buffington>, <ITRON>

  13. Data Processing Diagram “PHY header processing” Data whitening/ scrambling (optional) FEC (optional) Generate PHR Preamble insertion Compute CRC-32 FEC for PHY header (optional) RF MOD MAC-PDU FEC (optional) De-scrambling (optional) Data Detection Synch FEC for PHY header (optional) Compute CRC-32 RFDMOD “PHY header processing” <Daniel Popa, John Buffington>, <ITRON>

  14. Proposal Benefits <Daniel Popa, John Buffington>, <ITRON>

  15. Proposal benefits • Provides a low cost implementation. • Provides some recommendations for improving the PHY Layer. • Can be harmonized with other slow FH systems. <Daniel Popa, John Buffington>, <ITRON>

  16. Harmonization with other slow/MAC FHSS proposals(Referencing common platform documents) <Daniel Popa, John Buffington>, <ITRON>

  17. Source: 15-09-0298-01-004g, May 7, 2009. Octets min 4 2/4 4 variable Bits 32 16/32 4 2 10 4 2 10 variable Octets min 4 2/4 2 2 variable Field Preamble/SYNCH SFD NID Reserved Frame length NID-C Reserved-C Frame length-C PSDU (MAC-PDU + FEC) Bits 32 16/32 4 2 10 16 variable SHR PHR PHY payload Field Preamble/SYNCH SFD NID Reserved Frame length Optional FEC PSDU (MAC PPDU + FEC) SHR PHR PHY payload <Daniel Popa, John Buffington>, <ITRON>

  18. Octets min 4 2/4 2 variable Bits 32 16/32 4 1 11 variable Field Preamble/SYNCH SFD NID Extension Frame length PSDU (MAC-PDU + optional FEC) SHR PHR PHY payload 2 4 2 10 Octets min 4 2/4 2 NID-C Ext-C Length-C Bits 32 16/32 4 1 11 2 Field Preamble/SYNCH SFD NID Ext Frame length Other extensions 16 Optional FEC variable Other extensions SHR variable PHR PSDU (MAC-PDU + optional FEC) PHY payload <Daniel Popa, John Buffington>, <ITRON>

  19. <Daniel Popa, John Buffington>, <ITRON>

  20. <Daniel Popa, John Buffington>, <ITRON>

  21. THANK YOU FOR YOUR ATTENTION Q & A <Daniel Popa, John Buffington>, <ITRON>

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