Submission Title: [ Wireless Neighborhood Area Networks – WNAN ] Date Submitted: [ 15 July, 2008 ]

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Wireless Neighborhood Area Networks – WNAN ] Date Submitted: [ 15 July, 2008 ] Source: [ George Flammer ] Company/Organization [ Silver Spring Networks ] Address: [ 575 Broadway, Redwood City, CA ] Tel [ 650-298-4200] E-Mail: [ gflammer (at) SilverSpringNet.com ] Re: IEEE 802 Plenary WNAN Tutorial Abstract: WNAN description, mesh network performance, appropriateness of 802.15.4 for WNAN Purpose: To brief IEEE 802 Membership on WNAN application area and need for standards 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.

2. Wireless Neighborhood Area NetworksWNAN July 15th, 2008 15-08-0457-00-0000

3. WNAN = Process Control • WNAN applications may be defined as wide area process control • Low BW – less than 100 kB per day • Latency tolerant - less than 10 seconds • Exceptional events require low single digit responses (e.g. less than 2 seconds) • Nominally fixed locations; not mobile. • Complete ubiquity: every device location connected – millions of locations, tens of thousands of square miles

4. WNAN ‘neighborhood’

5. The WNAN application space For process control, the WNAN extends from the computer to the monitored and controlled devices. For the Utility application, the WNAN logically extends ‘from the tower to the toaster’. Topologically, this can be 802.15.4 devices and relays being aggregated by 802.11/802.16 WAN to an 802.3 LAN.

6. Mesh networks provide scalable performance Average round trip time (RTT) of ~350 byte meter reads for 48,000 meters.

7. Mesh networks distribute intelligence Latency to any one endpoint is highly correlated with hop count. One mesh topology would have endpoints continually evaluate and improve their routes “in and out”. Multiple alternate paths in and out of the network are vetted and the best selected. Each endpoint can use available local information to plot routes in and out. Viewed globally, the highly scalable process ‘balances’ overall mesh load for highest performance.

8. Mesh networks utilize spectrum efficiently With RSSI in every radio, the radio spectrum can be measured everywhere; in this case hourly. This graphic shows signal occupancy across 26MHz (902-928MHz). These data were taken in a ‘small city’ environment – trolley cars, four lane streets, etc. The mesh network is in operation. Occupied channels are blue. Empty channels are red/pink trending toward white – spectrum sharing rules established by the FCC in the early 1990’s still work well.

9. Open Standards The power plug has been an ‘open standard’ for 100 years Leverages trillion dollar utility capital Millions of devices have been independently developed Plug it in and it ‘just works’ • IP provides the open standard for the Wireless NAN • Leverages trillion dollar collective R&D budget • Enables vendor community to develop products independently • Plug it in and it ‘just works’

10. The WNAN application space • Geographically distributed process control network • With a very large number of • High value endpoints in • Nominally fixed locations with • Handfuls of kilobytes moving • Within handfuls of seconds • Not a ‘fat’ pipe, but a ‘diverse’ pipe

11. The WNAN application space Industrial process control needs to be robust – you can never have enough range. With enough range, you have ubiquitous coverage. When you have complete coverage, you must have a scalable technology Which will not be used if it is not robust. The 802.15.4 PHY and MAC need to be tailored to meet the WNAN technical requirements.

12. WNAN – coexistence with standards Pulls WAN backhaul ----- and enables huge HAN market

13. WNAN – has most synergy with 802.15.4 802.15.4 PHY and MAC enhancements • Use 1W FHSS for part 15.247 • 100kbps FSK = 220kHz BWRange now > 10km • Packet size up to 2047 BytesCarries IP packets compatibly • FHSS and Slotted channel contentionRobust - survives own success • Power constraints unneeded • Processor constraints unneeded

14. Thank You