2006-01-16

S. Max, G.R. HiertzSlide 1

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Submission

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

Submission Title: [Challeges in (WPAN) Mesh Networks]Date Submitted: [16 January, 2006]Source: [Sebastian Max, Guido R. Hiertz] Company [Philips Research Laboratories Aachen, ComNets, RWTH Aachen University]Address [Kopernikusstr. 16, 52074 Aachen, Federal Republic of Germany]Voice:[+49-241-80-25-82-9], FAX: [+49-241-80-22-24-2], E-Mail:[smx@comnets.rwth-aachen.de]Re: []

Abstract: [To aid discussion.]

Purpose: [This document describes some problems inherent to mesh networks, some of them are especially severe in mesh WPAN networks. It should aid the discussion about different MAC schemes and which problems have to be solved in an efficient mesh WPAN MAC.]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.

2006-01-16

S. Max, G.R. HiertzSlide 2

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Submission

Challenges in (WPAN) Mesh Networks

Sebastian Max, Guido R. HiertzPhilips Research Laboratories

& Chair of Communication Networks, RWTH Aachen

Aachen, Germany

2006-01-16

S. Max, G.R. HiertzSlide 3

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A User’s Perspective: Applications

• Summary of CFA answers & analysis– High rate

• Home multimedia• PC cable replacement• Connect handheld

devices• Indoor location based

services– Low rate

• Home/office control• Security systems• Medical support• Industrial monitoring• Logistics / tracking

High throughput mesh network

Multi-hop extension

2006-01-16

S. Max, G.R. HiertzSlide 4

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Technical Requirements: High Rate

• Assumptions– Low mobility– Small to medium network size, mesh & tree topology

• Requirement – Easy setup, usage “self-organized”– High reliability– End-to-end throughput measured in Mb/s– End-to-end delay measured in ms, strict bounds

• Mesh benefit compared to non-mesh– Coverage extension– Route redundancy– High throughput over larger distance

2006-01-16

S. Max, G.R. HiertzSlide 5

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Submission

Technical Requirements: Low Rate

• Assumptions– Relatively low throughput (measured in kb/s)– Delay below 250ms– Low … medium mobility– Large networks, mainly mesh topology

• Requirements– Security & privacy– Low complexity– High reliablity

• Mesh benefit compared to non-mesh– Coverage extension– Route redundancy– Power saving

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Challenges

• Routing• Addressing• Power control• Topology control• Link adaptation• Single point of failure• Route redundancy• High rate

– Maintain high bit rate over several hops– Very delay sensitive– Distinct behavior of mains- and battery powered devices

• Low rate– Very efficient power saving– Scalability in network size / density and hop number

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S. Max, G.R. HiertzSlide 7

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Problems inherent to WPAN-Mesh

• Limited horizon• Power consumption• Interference Awareness• Route fairness• Reliability

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S. Max, G.R. HiertzSlide 8

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Mesh Device

Limited Horizon

• Local knowledge– Limited by Rx

range• Extended impact

– Interference– Congestion

Consequence aware MAC

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S. Max, G.R. HiertzSlide 9

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Power Consumption

• High demands for relay nodes

• Power save vs. relay job• Transmission power control Power aware MAC

2006-01-16

S. Max, G.R. HiertzSlide 10

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Interference Awareness

• Mutual interference

• System capacity shared

• Walls attenuate interference

• Capacity increase possible

Interference aware MAC

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S. Max, G.R. HiertzSlide 11

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Route Fairness

• Short versus long route– Punishment of multihop routes– Cumulative bandwith of several hops– Retransmission of lost packets

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S. Max, G.R. HiertzSlide 12

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Reliability

• Avoid single point of failure– Routing– Transmit control (channel, time, power, …)

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S. Max, G.R. HiertzSlide 13

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Mahalo for your attention!

Questions?Discussion!