Ad Hoc Relay Mode for Mobile Coverage Extension and Peer-to-Peer Communications IEEE Presentation Submission Document Number: IEEE S802.16m-07/260r2 Date Submitted: Source: Jeff Bonta, George Calcev, Steve Emeott,Voice: Benedito Fonseca, Nitin Mangalvedhe, Nathan Smith Venue: IEEE m-07/040 Base Contribution: IEEE C802.16m-07/260 Purpose: This proposal requests inclusion of appropriate sections in the SDD for Ad Hoc Relay Mode for coverage extension and peer-to-peer communications Notice: This document does not represent the agreed views of the IEEE Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

2 Motivation for Ad Hoc Relay Mode m Requirements –The IMT-Advanced Network Topology proposes multi-hop, mesh and P2P (peer-to-peer) modes –The m operational requirements call for: Multi-hop relay support –Tremendous opportunity for network architectures that scale with low cost mobile stations Self-optimization of network performance with respect to service availability, QoS, network efficiency and throughput –Supports coverage extension, infrastructure-offloading, and other usage models

3 Motivation for Ad Hoc Relay Mode (continued) Usage Models –Coverage/Range Extension Micro-holes/shadowing/fringe coverage Improved throughput –In-building Penetration Multi-hop relay from fixed “seed” Improved service availability –Infrastructure Offloading BS controlled P2P file transfers, gaming, video streaming Improved network efficiency –Unique Application Support BS controlled Social Networking, Public Safety –Improved Frequency Reuse Improved network efficiency

4 Limitations of Current Technologies Mesh Mode –Not integrated with legacy PMP mode. Frame is either Mesh or PMP –Expensive overhead. Alternating Mesh and PMP frames reduces QoS with large latency between PMP frames j Relay Mode –Relay stations are not allowed to forward the traffic between two MS nodes. Ad Hoc capable MS can be a source, destination, or a relay Does not permit modification of mobile stations to be used as relays –Current j frame cannot manage the unscheduled asynchronous nature of peer-to-peer connections No ability for peer communications (broadcast, unicast, or multicast)

5 Ad Hoc Relay Mode Requirements Control and access mechanisms that allow MS peers to synchronize and communicate with one another –Out-of-coverage MS nodes need network synchronization –Peer nodes need a mechanism for discovering a communication path between them –Peer nodes require the ability to negotiate with peer nodes for traffic channel resources for P2P communications Self-optimization should maximize opportunity for spatial reuse Negotiation should be BS supervised Physical layer design: –Preamble design for AGCing to prevent near-far data transmission from saturating receiver. –Synchronization must be enhanced to mitigate multi-access interference General –Solution needs to be lean, yet integrated to coexist with legacy point-to-multipoint (PMP) services –Adaptive to traffic demands for ad hoc communications to maximize network efficiency –Opportunistic with respect to the proximity of ad hoc capable MS devices –Flexible and simple to allow self-optimizing deployment tailored to the environment –Self-optimized deployment should limit the configuration of an ad hoc relay network to a small number of short hops

6 Inclusion of an “Ad Hoc Zone” in Frame DSC (Distributed Synchronization Channel) –Provides ability for nodes to send a beacon for network synchronization of out-of-coverage MS nodes UAC (Unscheduled Access Channel) –Multi-access channel for communications between direct peers (e.g. routing and hello messages, and resource negotiations) ADCH (Ad Hoc Data Channel) –Traffic resources negotiated between direct peers of a mesh connection on UAC –BS supervises

7 Ad Hoc Zone Superframe Repetition of the Ad Hoc Zone –One DSC and one UAC per frames –Ad Hoc Zone can utilize 3 or more symbols from a frame –Repetition and frequency of each channel adaptive to traffic demands

8 Suggested Changes to System Description Document MAC Resource Control and Management Functions –Radio Resource Management (RRM): Ad Hoc Resource Negotiation and Allocation –Routing Physical Layer Multiple Access Methods –Ad Hoc Relay Physical Layer OFDMA Numerology and Frame Structure –Ad Hoc Zone – Physical Data Channels – Physical Control Channels It is envisioned that other existing sections will be impacted Include interface in the network architecture between IEEE m MSs