Ad Hoc Relay Mode for Mobile Coverage Extension and Peer-to-Peer Communications IEEE 802.16 Presentation Submission Document Number: IEEE S802.16m-07/260 Date Submitted: 2007-11-07 Source: Jeff Bonta, George Calcev, Steve Emeott, Voice: Benedito Fonseca, Nitin Mangalvedhe, Nathan Smith Motorola E-mail: jeff.bonta@motorola.com Venue: IEEE 802.16m-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 802.16 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 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: <http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>. Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >. Motivation for Ad Hoc Relay Mode • 802.16m Requirements – The IMT-Advanced Network Topology proposes multi-hop, mesh and P2P (peer-to-peer) modes – The 802.16m 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 2 Motivation for Ad Hoc Relay Mode (continued) • Usage Models – Coverage/Range Extension • Micro-holes/shadowing/fringe coverage • Improved throughput – In-building Penetration – Improved Frequency Reuse 1 Social Networking 6 Infrastructure offloads of high data rate apps – Video, Gaming Ad Hoc Relay 7 Infrastructure offloads - File Transfers Ad Hoc Multi-hop Relay 3 Ad Hoc Relay Ad Hoc Multihop Relay 5 8 9 Frequency Reuse – Unique Application Support • BS controlled Social Networking, Public Safety Ad Hoc Multi-hop Relay Ad Hoc Multi-hop Relay Internet • BS controlled P2P file transfers, gaming, video streaming • Improved network efficiency Low Cost Range Extension Low Cost Coverage Hole Filling 4 • Multi-hop relay from fixed “seed” • Improved service availability – Infrastructure Offloading 2 In-building Penetration Traffic Channel Public Safety Control Link 16m ad hoc capable node Legacy 16e node • Improved network efficiency 3 Limitations of Current Technologies • 802.16 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 • 802.16j Relay Mode – Relay stations are not allowed to forward the traffic between two MS nodes. Mesh capable MS can be a source, destination, or a relay • Does not permit modification of mobile stations to be used as relays – Current 802.16j frame cannot manage the asynchronous and dynamic nature of peer-to-peer connections • No ability for peer communications (broadcast, unicast, or multicast) 4 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 frequency 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 5 Inclusion of an “Ad Hoc Zone” in Frame New Ad Hoc Zone D S C Frequency MAP Primary band allocations DL ... U A C UL ... o r A D C H RACH Primary Channel Frame Each logical channel is allocated periodically for direct link/mesh control (e.g. routing and resource negotiation) and traffic. • 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) – • Time 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 6 Ad Hoc Zone Superframe Example of a heavier loaded system of Ad Hoc Zones Distribution 1 2 3 4 5 802.16e/m frames 1 2 3 4 6 802.16 frame 7 8 9 10 11 12 13 14 15 16 17 18 19 20 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time 5 6 Example of a lighter loaded system of Ad Hoc Zones Distribution UAC ADCH MAP Frequency DSC 802.16 frame Primary band allocations DL ... A D C H UL ... RACH 4 symbols per frame Time • Repetition of the Ad Hoc Zone – One DSC and one UAC per 20-40 frames – Ad Hoc Zone can utilize 6 or more symbols from a frame – Repetition and frequency of each channel adaptive to traffic demands 7 Suggested Changes to System Description Document • Mobility Management: – • Ad Hoc Relay Handover Radio Resource Management (RRM): – Ad Hoc Relay Services • • • • MAC Control and Signaling, complement sections on Uplink and Downlink: – Ad Hoc Relay • • • Ad Hoc Relay Physical Layer MIMO Structure, complement sections on Uplink and Downlink: – • Ad Hoc Relay Physical Layer Signal Modulation, complement sections on Uplink and Downlink: – • Ad Hoc Relay Physical Layer Channel Coding, complement sections on Uplink and Downlink: – • Ad Hoc Relay Physical Layer Duplexing Mode, complement sections on Uplink and Downlink: – • Ad Hoc Relay Physical Layer OFDMA Numerology and Frame Structure: – • Common Control Signaling Dedicated Control Signaling Physical Layer Multiple Access Methods, complement sections on Uplink and Downlink: – • Routing Synchronization Resource Negotiation and Allocation Ad Hoc Relay It is envisioned that other existing sections will be impacted 8