Overview of IEEE802.11s - Wireless Aware L2 Mesh Networks

Transcription

1 APNOMS 00 September 9 Overview of IEEE80.s - Wireless Aware L Mesh Networks Yoichi Matsumoto Communications Business Development Group Intel KK Mesh Related IEEE80 Organization Working Group Task Group Industrial Group IEEE80. IEEE80.s WiFi WiFi IEEE80 IEEE80. IEEE80.. WiMedia IEEE80.. IEEE80.. ZigBee ZigBee IEEE80. Wimax Wimax 0

2 IEEE80. WLAN Network Configurations AP: Access Point : Mesh Point MAP: Mesh Access Point R: Mesh Portal LAN LAN/IP Network AP R MAP MAP (a) Infrastructure (b) Adhoc (ibss) (c) Mesh Networks () Residential Major Usage Scenarios () Campus/ Community / Public Access Network () Office University Campus Community Area Park Area Source:IEEE P80.-0/ 0

3 Backgrounds and Motivations Core building block for ubiquitous communications society Mesh NWs provide: Higher throughput (short distance) / low-power consumption NW robustness enhancement Increased NW capacity (frequency spatial reuse) Flexible NW deployment (coverage, timing) Prevailing/maturing WiFi Technologies (AP, PC, CE, HH) Progresses of research MANET: solid Layer- routing research outcomes WiFi based practical, interoperable and extensible mesh networks (High-level Requirements) Why L Mesh Networks? Device power consumption and cost reduction High speed and small latency Usability with current applications (eg.. little effects on upper layer) Effective use of radio resources (Detailed Technical Requirements) L wireless technology parameter optimization (e.g. L flow control for buffer-overflow in multi-hops) Multi-channel Interface operation (e.g. mixture of single and dual) Frequency resource allocation in varying environments (e.g. traffic fic pattern, vs. Infra.) Practical QoS-aware power consumption reduction (APSD: advanced power save delivery) 0

4 Layer- Mesh Basic Frame Formats Data frame format MAC Header Octets: 0- Frame Dur Addres s Addres s Addres s Seq Addres s QoS Mesh Forwar ding Body FCS Management frame format Octets: 0- Frame Duration DA SA BSSID Seq Frame Body FCS Source: IEEE s-80--tgs-simpleefficient-extensible-mesh-seemesh-proposal.doc WLAN Mesh Capability Element Formats WLAN Mesh Capability element (in beacons/probe-responses to notify active path selection protocol, active path metric) Octets: ID Length Version Active Protocol ID Active Metric ID Peer Capacity Power Save capability Channel Precedence Protocol identifier format Octets: OUI Protocol Identifier Protocol Identifier Values Source: IEEE s-80--tgs-simpleefficient-extensible-meshseemesh-proposal.doc OUI 00-0F-AC 00-0F-AC 00-0F-AC 00-0F-AC Vendor OUI Value - Other 0 Meaning Radio Metric AODV (default path selection protocol) Radio Aware OLSR (optional path selection protocol) Reserved for future use Null protocol Vender specific 8 08

5 Expected 80.s Functional Component Architecture Source:IEEE P80.-0/ Upper Layers Mesh Internetworking Mesh Configuration and Management 80.s WLAN Mesh (L) Mesh Topology Learning and L Routing/ Forwarding Mesh Network Measurement Mesh Medium Access Coordination (including QoS) Mesh Security MAC Lower MAC enhancement for Mesh (e/n+) PHY (L) IEEE80. PHY IEEE80. a/b/g/j/n 9 Hidden/Exposed Nodes Source:Akira Yamada, et. al, "Enhancement of Mesh Network Oriented IEEE80. MAC Protocol, Technical report of IEICE, RCS00-8, April, 00 Case (a) Case (b) Case (c) Case (d) Case (a) Normalized Total Throughput (%) to to Case (b) Case (c) (a) (b) (c) (d) Case (d) 0 09

6 MAC Level Flow s Actual Scheduling Result when load=00kb/s k 9k k k 8k k 0k 9k Rx: 8k 00k 899k 0k k Tx: k 8k 0k 8k 9k Source: IEEE P80.-0/0 ee throughput Congested nodes Wasted TX Ideal Scheduling, when the network is overloaded 0k 0k 0k 0k 0k 0k 0k 0k Rx: 0k 80k 80k 80k 80k Tx: 0k 80k 80k 80k 0k ee throughput Layer- Mesh Routing Protocol Table Driven Conformance with Legacy LAN Reactive Implementation for various devices (mandatory for interoperability) Quick/flexible response to changing radio/traffic environments Extensibility for multi-radio I/F operation Routing Protocol Route Maintenance Forwarding Process AODV DSR OLSR TBRPF Reactive Reactive Proactive Proactive Table driven Source routing Table driven Table driven 0

7 Recommended Basic Radio Metric Air Time c a = O ca + O p + B r t e pt Airtime Cost Constants Parameter O ca O p B t Value (80.a) ms 0ms 8 Rate dependent on local implementation of rate adaptation Value (80.b) ms ms 8 Description Protocol overhead Frame error rate for test frame size Bt Channel access overhead Number of bits in test frame Source: IEEE s-80--tgs-simpleefficient-extensible-mesh-seemesh-proposal.doc Radio Metric AODV with Multi-radio Interfaces Nodes with different single/multiple I/Fs Avoid high QoS node Non-radioaware AODV x: Radio metric A 0 D B C F E 0 G H 0 I A 0 D B C F E 0 G H 0 I When costs equal, chose first-arrival path RM-AODV

8 Overall Functional Operation Initial mode Operating mode sec. min. Initial Freq. channel Setting MAC Parameter Optimization msec. Layer- Routing Freq. Channel setting An Experimental System (home) Source: IEICE RCS, July 00, Performance Evaluation of Layer- Mesh Networks -Technical Challenge Clarification on Conventional IEEE80. Standard Technology- Koji Omae, et.al MS: Media server : Media player Hi-vision video stream VoIP stream Internet TEL a WC MS AP (GW) Room Bath K Internet TEL MAP MS MAP (GW) Room WC Bath K Internet TEL MAP MS MAP (GW) Room m WC Bath K Internet TEL g MAP a a MS MAP (GW) Room WC Bath K a m LD TEL Balcony TEL LD Balcony High priority LD TEL Balcony LD TEL Balcony (a) Non-mesh WLAN network (b) Plain mesh network (c) Mesh network w/ EDCA based MAC (d) Mesh network w/ multi-ch. allocation

9 Experimental Results Source: IEICE RCS, July 00, Performance Evaluation of Layer- Mesh Networks -Technical Challenge Clarification on Conventional IEEE80. Standard Technology- Koji Omae, et.al Round trip time (msec) Throughput (Mbps) Non-mesh WLAN Video throughput. Conventional WLAN. Plain mesh network 8. VoIP RTT (internal). Mesh w/ multi- EDCA based QoS channel allocation.0 Plain mesh network Mesh Mesh w/ w/ QoS multichannel (VoIP) allocation. Mesh w/ EDCA Mesh w/ multichannel based QoS allocation 8.0 Mesh w/ w/ EDCA two channels based QoS Interworking (Requirement) Interworking with Layer networks (LAN networking with broadcasting ) (Approach) Conformance with IEEE80.D bridge Loop avoidance with Spanning Tree (between s) IEEE80. s Spanning Tree Protocol and bridge management IEEE80.D MAC relay MAC (inc, IEEE80.s) Mesh Portal LAN 8

10 Basic Security Model Example Authenticator Supplicant ESS Mesh Security bubble New mesh point Supplicant Authenticator Group key for broadcast communications Pair-wise keys for unicast communications Authentication server could be distributed or centralized Source: IEEE P80.-0/r 9 Summary Mesh WLAN (IEEE80.s) improves robustness, coverage, and capacity for multiple streams Get ready for mesh networking Get involved in the standards organizations Design compatible products IEEE80.s Schedule (submission deadline: June 00) Presentation of proposals: July 00 Technical Specification First Version: March 00 Technical Specification Ratification: June 008 For more information IEEE80. IETF MANET ietf.org/ 0