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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [SG-NAN: WNAN Technical Discussion] Date Submitted: [ 10/25/2014 ] Source: [Name] [Company] [E-Mail] [Will San Filippo] [Silver Spring Networks] [wills @ silverspringnet.com]
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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [SG-NAN: WNAN Technical Discussion] Date Submitted: [10/25/2014] Source: [Name] [Company] [E-Mail] [Will San Filippo] [Silver Spring Networks] [wills @ silverspringnet.com] [Jana van Greunen] [Silver Spring Networks] [jvangrue @ silverspringnet.com] [George Flammer] [Silver Spring Networks] [gflammer @ silverspringnet.com] [Sterling Hughes] [Silver Spring Networks] [sterling @ silverspringnet.com] [Ben Rolfe] [Blind Creek Associates] [ben @ blindcreek.com] Re: Neighborhood Area Network Study Group Abstract: Presents a brief overview of application requirements identified in prior IG/SG presentations and discusses architectural concepts focused on the application requirements. Purpose: Stimulate discussion in the Study Group. 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. San Filippo, van Greunen, Flammer, Hughes, Rolfe
SG-NAN Technical Discussion Slides San Filippo, van Greunen, Flammer, Hughes, Rolfe
Contents Application Requirements Overview Very Large Scale Process Control Examples: Utility networks, industrial, others Architectural Concept Based on proven systems Narrow Band-PHY Channel Hopping Slotted Random Access MAC San Filippo, van Greunen, Flammer, Hughes, Rolfe
WNAN Definition A WNAN is A scalable network Constructed of simple, low cost, modest devices Key objectives of the WNAN Extreme scalability (to tens of millions of nodes) High availability (uptime) Highly reliable data delivery (error detection) Ease of commissioning (highly autonomous) San Filippo, van Greunen, Flammer, Hughes, Rolfe
WNAN “Neighborhood” Example San Filippo, van Greunen, Flammer, Hughes, Rolfe
Application Requirements Key differentiators Ubiquity (100% coverage) System longevity (decades) Non-mobile (infrastructure overlay) Cost sensitive (CapEx and OpEx) Reliable, robust, flexible San Filippo, van Greunen, Flammer, Hughes, Rolfe
Cost Factors Total cost Long life - OpEx / CapEx Deployment / Acquisition No on-site (truck roll) maintenance Devices transparent to customers Space/power constraints not as critical But power may become more so Standards yield good economics San Filippo, van Greunen, Flammer, Hughes, Rolfe
Very Large Scale Process Control Scale == millions of nodes per network Ad hoc, multi hop, self-organizing, self-healing Optimized for robustness, ubiquity over data rate Flexible, resilient topology Geographically Diverse Non-mobile (but we don’t get to pick fixed location) Environment not static Tolerant of long, bounded latency San Filippo, van Greunen, Flammer, Hughes, Rolfe
Some References https://mentor.ieee.org/802.15/documents San Filippo, van Greunen, Flammer, Hughes, Rolfe
WNAN Architectural Concept • Wireless Neighborhood Area Networks • Built from interconnected short-range links • Interconnected over large service territories • Based on proven systems • PHY – Narrow band – longer range, robust • MAC - Channel hopping, slotted, random access San Filippo, van Greunen, Flammer, Hughes, Rolfe
WNAN Definition A WNAN is Scalable network Simple, low cost, modest throughput devices Optimized for Extreme scalability High availability (robustness) Highly reliable data delivery Ease of commissioning. San Filippo, van Greunen, Flammer, Hughes, Rolfe
Some characteristics WNAN • Data rate commensurate with long range (~100 kbps) • Very high reliability and availability • Peer to Peer with minimal infrastructure (self-forming) • Large scale mesh networking support • Support for route diversity • Fully acknowledged data transfer (error detection) • Support for IP datagrams San Filippo, van Greunen, Flammer, Hughes, Rolfe
WNAN Context San Filippo, van Greunen, Flammer, Hughes, Rolfe
NAN Context (2) – In-premise San Filippo, van Greunen, Flammer, Hughes, Rolfe
Architectural Characteristics Topology Peer-to-Peer Star/cluster Good Mesh platform San Filippo, van Greunen, Flammer, Hughes, Rolfe
Layers San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics Narrow band channels with many channels per band Fit FCC part 15.247 criteria for 1W FHSS Optional operation in multiple bands sub-GHz, 2.4GHz, EU, Japan, India, China, etc. Support for efficient channel hopping Efficient support for IP datagrams At least 1,500 Octet Ethernet MTU payload Robust, simple modulation/demodulation Data “whitening” (scrambling) Low data rate (~100 Kbps) San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (2) Bands (examples) 868–868.6 MHz (Europe, China) 902–928 MHz (Americas, China, others…) 2400–2483.5 MHz (worldwide) 950-956 MHz (Japan) 779-787 MHz (China) 865.6-867.6, 840.5-844.5, … San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (2) Bands (examples) 868–868.6 MHz (Europe, China) 902–928 MHz (Americas, China, others…) 2400–2483.5 MHz (worldwide) 950-956 MHz (Japan) 779-787 MHz (China) 865.6-867.6, 840.5-844.5, … Obvious choices San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (2) Bands (examples) 868–868.6 MHz (Europe, China) 902–928 MHz (Americas, China, others…) 2400–2483.5 MHz (worldwide) 950-956 MHz (Japan) 779-787 MHz (China) 865.6-867.6, 840.5-844.5, … With narrow bandwidth channels, there are some under-used slices of spectrum that we can now use. San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (3) Narrow Bandwidth Robust performance More power possible Can make use of under-used spectrum Channel Hopping Support Independent of band Constraints on channel switch timing Support for needed sync mechanisms San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (4) Robustness over Bits per Second NB+ hopping + adaptation Adaptive Channel Agility Simple modulation and coding PHY layer error detection Effective whitening San Filippo, van Greunen, Flammer, Hughes, Rolfe
NB-PHY Characteristics (5) • Optimize for narrow channels (~250kHz -20dB BW) and the most non-overlapping channels that fit the band • Robust modulation/demodulation: • Tolerance of simultaneous channel occupancy • Independent of data patterns and pattern lengths • Monotonic Received Signal Strength Indication (RSSI) • Transmit Power Control (TPC) • Interoperability specifications (radio): • Receiver sensitivities (min) • Receiver adjacent and alternate channel rejection (min) • Frequency stability (min) • Transmit & power amplifier rise and fall times (max) • Channel to channel slew times (per band) (max) San Filippo, van Greunen, Flammer, Hughes, Rolfe
MAC Goals Optimized for: Channel hopping w/narrow band PHY Many channels Interference avoidance High data delivery reliability Low data rates Effective support of IP datagrams Efficient support to upper layers for ad-hoc, multi-hop networking (Mesh). San Filippo, van Greunen, Flammer, Hughes, Rolfe
MAC Characteristics Channel hopping Support for prioritized traffic Support for near-neighbor discovery San Filippo, van Greunen, Flammer, Hughes, Rolfe
Channel Hopping Overview • Maximize number of hopping sequences • Minimize network overhead • 100% channel revisit (regulatory requirement) • Support for channel masking (co-existence) • Support for lots of channels (robustness) San Filippo, van Greunen, Flammer, Hughes, Rolfe
Synchronization Global synchronization option Difficult in very large networks Requires centralized time distribution Local (single hop) synchronization Requires only peer exchange of synchronization information San Filippo, van Greunen, Flammer, Hughes, Rolfe
MAC Support for Neighbor Discovery Provides mechanism to acquire information about neighbors Supports handshake to obtain timing info Maintains neighbor synchronization (local) San Filippo, van Greunen, Flammer, Hughes, Rolfe