Ad Hoc Relay Mode for Mobile Coverage Extension and Peer-to-Peer Communications
IEEE 802.16 Presentation Submission
Document Number:
IEEE S802.16m-08/003r1
Date Submitted:
2008-01-16
Source:
Jeff Bonta, Mike Baker, George Calcev, Steve Emeott,
Voice:
Benedito Fonseca, Nitin Mangalvedhe, Nathan Smith
Motorola
E-mail:
jeff.bonta@motorola.com
Venue:
Levi, Finland
IEEE 802.16m-07/047. Contribution pertains to:
Proposed 802.16m Frame Structure with special attention to legacy support
Base Contribution:
IEEE C802.16m-08/003
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 >.
Ad Hoc Relay Mode Defined
• 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
• Self optimization of network performance
• “Ad Hoc Relay” uniquely identifies 802.16m multi-hop relay capabilities:
– Enables self-optimizing multi-hop mesh and P2P communications
– Integrated solution distinguishes itself from the prior IEEE 802.16 Mesh Mode
Ad Hoc Relay enabling
coverage extension via
an MS
RS
BS supervised P2P
utilizing Ad Hoc
Relay enables spatial
reuse
Traffic Channel
Control Link
BS
Legacy
16e node
16m ad hoc
capable node
Internet
2
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 and control
– Peer MS 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
•
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
•
Objective
– Define a frame structure to support coverage extension via an MS and/or P2P
communications utilizing MS nodes
3
Inclusion of an “Ad Hoc Zone” in Frame
• Ad Hoc Zone is a TDM allocation in the UL sub-frame
– Enables meshing of MS nodes in ad hoc relay configurations with peer-to-peer
communications
• Ad hoc Zone would best be defined within the UL sub-frame
– Insures that all peer-to-peer communications occur at the same time as other
UL transmissions within the system
• Mitigates the potential for interference
• Symbols normally allocated to the Ad Hoc Zone are re-allocated to the
IEEE 802.16m UL sub-frames when the Ad Hoc Zone is not present
– The presence of the Ad Hoc Zone is dependent on 16m and ad hoc relay traffic
10 MHz
Frequency
One 5 msec
frame
Subframe
0
Subframe
1
Subframe
2
Subframe
3
Subframe
4
Subframe
5
Subframe
6
Subframe
7
Ad
Hoc
Zone
(opt.)
Time
4
Symbol Definitions of Ad Hoc Zone
•
Subframe
6
Subframe
7
– Data Symbol is logical channel representing
an UAC, ADCH, or DSC
– Optional Preamble Symbol enables physical
layer synchronization for MS peer nodes that
are out of the coverage of the BS
– Guard Symbol provides Tx/Rx turn around
time
Ad
Hoc
Zone
(opt.)
ADCH
•
Same numerology as IEEE 802.16m
– Symbol duration
– Cyclic prefix length
– Sub-carrier spacing
Guard Symbol (opt)
Guard Symbol (opt)
UAC
Ad Hoc Zone
Logical
Channels
Guard Symbol (opt)
Subframe
5
ADCH
Subframe
4
Guard Symbol
Subframe
3
The Ad Hoc Zone utilizes 3 OFDM symbol
types:
UAC
Subframe
2
Subframe
1
Guard Symbol
Subframe
0
Preamble Symbol
DSC
10 MHz
Frequency
One 5 msec
frame
Example Logical Channel Patterns of a 6 symbol Ad Hoc Zone
5
Ad Hoc Zone Logical Channel Definitions
• UAC (Unscheduled Access Channel)
– Means to enable 802.16m Ad Hoc Relay capable MS nodes to communicate
P2P without utilizing the BS and without coordination from the BS
• Multi-access channel for communications between direct MS peers (e.g. resource
negotiations and routing messages)
• ADCH (Ad Hoc Data Channel)
– Unique set of communication resources that enable multiple simultaneous ad
hoc communications
– Traffic resources are negotiated between direct peers of a mesh connection on
UAC
– May occupy one or more adjacent symbols
– BS supervises
• DSC (Distributed Synchronization Channel)
– Means to synchronize and forward control information to MS nodes that are
out of the 802.16m system coverage
• Provides ability for nodes to send a beacon for network synchronization of out-ofcoverage MS nodes
– Always preceded by a Preamble Symbol at start of Ad Hoc Zone
6
Multi-Access Ad Hoc Communications
Logical Control
Channel Example
DSC
UAC
Data and Feedback
Example (e.g. FTP w/ACK)
Data
ACK/Ctrl
VoIP Example
Fwd VoIP
Rev VoIP
Transmitting node A
Transmitting node B
Guard symbol
• Multi-Transmission Opportunities in Ad Hoc Zone
– A single source and destination,
– A single source and multiple destinations, or
– Multiple sources with either single or multiple destinations
• Efficient use of the Ad Hoc Zone would permit:
– Nodes to transmit and receive within the same Ad Hoc Zone
• Permissible logical channel patterns depend on the uplink
permutations and pilot structures
– UL adjacent sub-carrier permutation must permit 3-symbol tiles to
maximize efficiency of Ad Hoc Zone
7
UL Permutation and Ad Hoc Zone Mini-Tiles
AHZ
AHZ
Mini-Tile Mini-Tile
7
Pilot Symbol
– Ad Hoc Zone Mini-Tile is
proposed (3 symbols x18 subcarriers) to:
• Maximize Ad Hoc Zone
Efficiency
• Reduce delay
5
Data Symbol
6
8
9
10 11 12
Slot Format 1
– Referenced contributions
2
3
4
Guard Symbol
(when necessary)
1
Freq
13 14
15 16 17 18
• Example Permutation and
Pilot Structure
1 2 3 4 5 6
• IEEE C802.16m-08/008
• IEEE C802.16m-08/012
Time
8
Ad Hoc Zone Superframe
Example of a heavier loaded
system of Ad Hoc Zones
Distribution
3
4
5
802.16e/m frames
1
2
3
4
6
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
Subframe
0
Subframe
1
Subframe
2
Subframe
3
Subframe
4
Subframe
5
Time
5
6
Example of a lighter loaded
system of Ad Hoc Zones
Distribution
DSC
UAC
ADCH
802.16 frame
10 MHz
2
Frequency
1
802.16 frame
Subframe
6
Subframe
7
Ad
Hoc
Zone
(opt.)
One 5 msec frame
1 or 2 AHZ data symbol types in a sub-frame
Time
• Repetition of the Ad Hoc Zone
– Superframe interval based on minimum periodicity of the DSC
– Minimum of one DSC and one UAC per 20-40 frames
– Repetition and frequency of each channel adaptive to traffic demands
9
Impact to MAC Common Part Sub-Layer Functional
Blocks
• Ad Hoc Self-Organization
– Supports network synchronization procedures related to the configuration and
control of 802.16m MSs that are out of the coverage of the BS
• Ad Hoc Routing
– Manages discovery and maintenance of multi-hop connections through MSs
– Route discovery procedures for path optimization of routes between MS, RS,
and BS
– Route discovery procedures allowing the BS to initiate a path minimization
function to improve resource utilization
• Ad Hoc Mobility Management
– Procedures to enable a multi-hop relay connection via a MS to be handed over
to a PMP connection with the BS, and visa versa
• Ad Hoc Radio Resource Management
– Dynamic configuration of the Ad Hoc superframe periodicity of the Ad Hoc
Zone
• Based on traffic demands for multi-hop relay and P2P
– Procedures for resource negotiations between peer MS nodes
10
Suggested Changes to System Description
Document
• Physical Layer
– Frame Structure (new)
• Ad Hoc Frame Structure (new)
– Optionally insert text from section 2.1.1 of this contribution
• Ad Hoc Zone Logical Channel Definitions (new)
– Optionally insert text from section 2.1.2 of this contribution
• Ad Hoc Superframe (new)
– Optionally insert text from section 2.1.3 of this contribution
• MAC Common Part Sub-Layer
– Resource Control and Management Functions (new)
• Ad Hoc Relay Self-Organization (new)
– Optionally insert text from section 3.1 of this contribution
• Ad Hoc Relay Routing (new)
– Optionally insert text from section 3.2 of this contribution
• Ad Hoc Relay Mobility Management (new)
– Optionally insert text from section 3.3 of this contribution
• Ad Hoc Relay Radio Resource Management (new)
– Optionally insert text from section 3.4 of this contribution
11