IEEE C802.16m-08/072
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Using relay station to provide Legacy support in 802.16m
Date
Submitted
January 10, 2008
Source(s)
Kanchei (Ken) Loa, Yi-Hsueh Tsai, TsungYu Tsai, Yung-Ting Lee, Hua-Chiang Yin,
Shiann-Tsong Sheu, Youn-Tai Lee,
loa@iii.org.tw
Institute for Information Industry
Re:
IEEE 802.16m-07/047: Call for Contributions on Project 802.16m System Description
Document (SDD)
Pertains to “Proposed 802.16m Frame Structure with special attention to legacy support”
Abstract
Using relay station to provide Legacy support in 802.16m
Purpose
For discussion and approval by IEEE 802.16 Working Group
(Consideration of using relay station to provide Legacy support in 802.16m)
Notice
Release
Patent
Policy
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Using relay station to provide Legacy support in 802.16m
Introduction
According to IEEE 802.16m system requirements document (IEEE 802.16m-07/002r4), IEEE 802.16m system
shall provide continuing support and interoperability for legacy WirelessMAN-OFDMA reference systems. The
following are backward compatibility requirements:
1.
An IEEE 802.16m MS shall be able to operate with a legacy BS, at a level of performance equivalent to
that of a legacy MS.
2.
Systems based on IEEE 802.16m and the WirelessMAN-OFDMA Reference System shall be able to
operate on the same RF carrier, with the same channel bandwidth; and should be able to operate on the
same RF carrier with different channel bandwidths.
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IEEE C802.16m-08/072
3.
An IEEE 802.16m BS shall support a mix of IEEE 802.16m and legacy MSs when both are operating on
the same RF carrier. The system performance with such a mix should improve with the fraction of IEEE
802.16m MSs attached to the BS.
4.
An IEEE 802.16m BS shall support handover of a legacy MS to and from a legacy BS and to and from
IEEE 802.16m BS, at a level of performance equivalent to handover between two legacy BSs.
5.
An IEEE 802.16m BS shall be able to support a legacy MS while also supporting IEEE 802.16m MSs on
the same RF carrier, at a level of performance equivalent to that a legacy BS provides to a legacy MS.
This contribution provides a concept of using relay station to provide legacy support in 802.16m, which meets
above requirements (see Figure 1).
16m BS
802.16m
Handover
802.16e
802.16m
16m MS
802.16m
802.16m Mode
16m RS
Legacy
16m RS Supporting Mode
802.16m
802.16e
16m MS
16e MS
Figure 1 The architecture of legacy support using relay stations
The proposed architecture may have the following advantages and disadvantages:
Advantages

Simplified 16m-BS design and implementation

On-demand legacy support at the hot spot, thus, RSs are not required in every cell.

Flexible in disabling legacy support

Higher throughput for 16e MS via the 16m-RS
Disadvantage

Both legacy and 16m features are required at the 16m-RS which provides legacy support

Non-uniform coverage for the legacy support
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IEEE C802.16m-08/072
IEEE 802.16m System Architecture
According to C80216m-07/299r2, some terminologies are defined as follows:
1.
IEEE 802.16m Base Station (BS) – A base station that implements the base station functionality of the
IEEE 802.16m specification. IEEE 802.16m BSs supports communications with IEEE 802.16m RSs, IEEE
802.16m MSs, and IEEE 802.16e MSs.
2.
IEEE 802.16m Relay Station (RS) – A relay station that implements the relay station functionality specified
in the IEEE 802.16m specification. IEEE 802.16m RSs support communication with IEEE 802.16m BSs,
IEEE 802.16m MSs, IEEE 802.16m RSs, and IEEE 802.16e MSs.
3.
IEEE 802.16m MS – An MS which supports the mobile station functionality specified in the IEEE
802.16m specification.
4.
IEEE 802.16e MS – An MS which supports the mobile station functionality compliant with the
WirelessMAN-OFDMA Reference System, as specified in IEEE 802.16m System Requirements (IEEE
802.16m-07/002r4).
Figure 2 shows the proposed access network architecture. The 16m BS and regular 16m RS is associated with
16m RSs, and the legacy-support-mode 16m RS is associated with 16e MSs. The R1 interface is specified by the
IEEE 802.16e-2005 standard. The R1m, R1mr interfaces are specified by IEEE 802.16m standard. R1mc
interface applies to the case when more than two hops is supported. Number of hops supported is for further
study.
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IEEE C802.16m-08/072
16m BS
R6
R8
16e MS
R1
16m RS
R1mr
16m BS
R6
Access Service Network
Gateway
R1m
16m MS
R1mc
16m MS
R1m
16m RS
Access Service Network
Layer 1 and Layer 2 protocols to be
specified by 802.16m standard
Figure 2 IEEE 802.16m Access Network Architecture
IEEE 802.16m Frame Structure
According to the IEEE 802.16m system requirement, IEEE 802.16m system shall provide continuing support
and interoperability for legacy WirelessMAN-OFDMA reference systems, i.e., the OFDMA TDD air interface
as profiled in WiMAX Forum System Profile Release 1.0.
1.
An IEEE 802.16m system and the legacy WirelessMAN-OFDMA reference systems should be able to
operate on the same RF carrier, with the same or different channel bandwidths
2.
An IEEE 802.16m BS shall support a mix of 16m and legacy MSs both operating on the same RF carrier
3.
An IEEE 802.16m BS shall support a handover of a legacy MS to and from a legacy BS and to and from a
16m BS
The following frame structures, based on C80216m-07/242r1 provide legacy MSs support. Figure 5(a) and 6(b)
illustrate the frame structure in the TDM mode, whereas Figure 6(a) and 6(b) show the frame structure in the
FDM mode.
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IEEE C802.16m-08/072
16e Legacy Frame
UL subframe
Legacy DL data
New zones for 16m
DL data
Legacy UL data
New zones for
16m UL data
TTG
Compressed MAPs
FCH
16e preamble
Compressed MAPs
16e preamble
16m BS
FCH
DC in view of 16m and legacy MSs
DL subframe
RTG
Figure 3 16m frame structure (TDM)
16m Frame
DL subframe
UL subframe
16m DL zones for
MS
16m UL zones
for MS
TTG
RTG
FCH
Legacy DL data
DL subframe
16e preamble
Compressed
MAPs
FCH
Legacy UL data
TTG
UL subframe
RTG
16e Frame
Figure 4 16m frame structure (TDM)
We proposed two types of frame structure to provide Legacy support in 802.16m using relay station.
5
DC in view of 16m and legacy MSs
16m UL zones
for MS
X-MAPs
16m preamble
X-MAPs
FCH
16m DL zones
for MS
16e preamble
Compressed
MAPs
16m BS
16m preamble
FCH
IEEE C802.16m-08/072
16m Frame
DL subframe
16m UL zones
for RS
TTG
(a)
16e Frame
UL subframe
DL subframe
RTG
Legacy UL
data
Receiving
Legacy DL data
R-TTG
(b) TTG
16e preamble
Compressed
MAPs
16e preamble
Compressed
MAPs
FCH
Transmitting
R-RTG
RTG
Figu
Figure 5 16m frame structure with RS (TDM)
16m Frame
DL subframe
UL subframe
16m DL zones for
RS and MS
16m UL zones
for RS and MS
TTG
For RS
communicating
with Legacy
MSs
For RS communicating with
Legacy MSs
(a) 16m BS frame structure
6
RTG
DC in view of 16m and legacy MSs
16m preamble
16m UL zones
for MS
For RS
communicating
with Legacy MSs
16m DL zones
for MS
16m MAPs
FCH
FCH
16m R-MAPs
16m MAPs
16m preamble
FCH
16m BS
16m RS
FCH
DC in view of 16m and legacy MSs
16m UL zones
for MS
16m DL
zones for RS
16m preamble
16m DL zones
for MS
16m MAPs
FCH
FCH
16m R-MAPs
16m MAPs
16m preamble
16m BS
FCH
UL subframe
Receiving
TTG
Transmitting
RTG
FCH
Legacy UL
data
Legacy DL data
DL subframe
16e preamble
Compressed
MAPs
16e preamble
Compressed
MAPs
FCH
R-TTG
TTG
UL subframe
R-RTG
16e Frame
(b) 16m RS frame structure
Figure 6 16m frame structure with RS (FDM)
7
RTG
DC in view of 16m and legacy MSs
For MR-BS
communicating
with 16m MSs
For MR-BS communicating
with 16m MSs
16m RS
For MR-BS
communicating
with 16m MSs
IEEE C802.16m-08/072