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:
2007-11-09
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.
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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 unscheduled
asynchronous 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
3 or more symbols in a frame
UL
...
RACH
Time
• Repetition of the Ad Hoc Zone
– One DSC and one UAC per 20-40 frames
– Ad Hoc Zone can utilize 3 or more symbols from a frame
– Repetition and frequency of each channel adaptive to traffic demands
7
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
• Physical Layer MIMO Structure
– Ad Hoc Relay
• It is envisioned that other existing sections will be impacted
8