IEEE C802.16n-11/0130r1
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Frame Structure for Talk-around Direct Communications
Date
Submitted
2011-07-19
Source(s)
Young-Ho Jung, Jihoon Choi
E-mail:
jihoon@kau.ac.kr, yhjung@kau.ac.kr
Korea Aerospace University
scchang@etri.re.kr
Sungcheol Chang, Eunkyung Kim,
Sungkyung Kim, Won-Ik Kim, Miyoung
Yun, Hyun Lee, Chulsik Yoon, Kwangjae
Lim
ETRI
Re:
Call for Comments on the 802.16n AWD
Abstract
This provides AWD text proposals for frame structure of talk-around direct communications
Purpose
To be discussed and adopted by 802.16 TGn
Notice
Release
Patent
Policy
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.
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
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<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>.
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IEEE C802.16n-11/0130r1
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Frame Structure for Talk-around Direct Communications
2
Young-Ho Jung, Jihoon Choi
Korea Aerospace University
Sungcheol Chang, Eunkyung Kim, Sungkyung Kim, Won-Ik Kim, Miyoung Yun, Hyun Lee, Chulsik
Yoon, Kwangjae Lim
ETRI
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1. Introductions
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To support direct communication in IEEE 802.16n, some dedicated resources can be assigned as described in
[1]. By dedicatedly reserving a part of communication resources for infra-structure communications, the
reserved resources are used to provide multiple pairs of direct communication in OFDMA (orthogonal
frequency division multiple access) manner with contention based transmission.
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In this contribution, we propose the frame structure for talk-around direct communications in IEEE 802.16n,
and define physical channels for talk-around direct communications. We propose the separate proposals for
details of physical channels for talk-around direct communications in [2] and [3].
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2. Frame structure for talk-around direct communications
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For talk-around direct communication, two types of infra-structure communication resources are dedicatedly
assigned:
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Common Direct Mode Zone: set of PRUs with fixed size and positions which are commonly assigned to
all cells (must be CRU)
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23
-
Cell Specific Direct Mode Zone: additionally assigned direct-mode resource blocks independently
assigned by each HR-BS (CRU or DRU) and information to receive cell specific direct mode region can
be obtained from common direct mode zone
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25
26
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Figure 1 shows an example of talk-around direct communication resource allocation. In the figure, some part
of uplink infra structure resources are assigned for common direct mode zone, and some part of uplink and
downlink infra structure communication resources are assigned for cell specific direct mode zone. By assigning
the same physical resources for common direct mode zone the following benefits can be obtained:
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Reduce the overhead of control channels to transmit allocation information of resources for direct-mode
communication
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Reduce the computation complexity and power to obtain synchronization for direct communication,
specially for the HR-MSs in the outside of HR-BS coverage
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IEEE C802.16n-11/0130r1
CSDMZ
cell-specific direct mode zone
common direct mode region
CSDMZ
CDMZ
CSDMZ
CSDMZ
cell-specific direct mode zone
common direct mode zone
CSDMZ
CDMZ
cell-specific direct mode zone
CSDMZ
cell-specific direct mode zone
CSDMZ
common direct mode zone
common direct mode zone
common direct mode zone
common direct mode zone
CSDMZ
CSDMZ
CSDMZ
CDMZ
CDMZ
CDMZ
Direct-mode S-preamble
Direct-mode P-preamble
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2
Figure 1. An example of talk-around direct communication resource allocation
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In [4] we proposed to assign four PRUs with highest PRU indices for each bandwidth option for common
direct mode zone. These four PRUs are always assigned for sub-band based PRUs except of DSAC = 0 or
USAC = 0, and because the sub-band based PRUs are always assigned for CRUs, these four PRUs can be
commonly assigned for direct communication zone for all cells without effecting the resource permutation of
infra-structure communication resources.
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As discussed in [1], if some of uplink resources are utilized for direct communication, the main victims of
mutual interference between direct communication and cellular communication are HR-MSs, however, if some
of downlink resources are utilized for direct communication, the main victims of mutual interference between
direct communication and cellular communication are cellular mode MSs. Therefore we propose to assign the
uplink part of PRUs with highest PRU indices for each bandwidth option for common direct mode zone. The
downlink parts of these PRUs can be preferentially assigned for cell specific direct mode region when some of
downlink resources are assigned for cell specific direct mode region.
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Logical frame of common direct mode zone is composed by collecting all resources of common direct mode
zone in a superframe as shown in Figure 2. In the example, there are three uplink subframes for each 5msec
frame. Frame structure of cell specific direct mode zone is extension of common direct mode frame structure
and it will be proposed in the next meeting.
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IEEE C802.16n-11/0130r1
Super frame
Direct mode
zone
Super frame
Direct mode
zone
Super frame
Direct mode
zone
Slot 1
Direct mode
zone
Slot 2
subframe
Synchronization
Channel
1
2
Dedicated
Channel
Supplementary
Channel
Figure 2. An example of common direct mode logical frame construction
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There are three physical channels for talk-around direct communication:
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Synchronization Channel (Sync-CH)
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Dedicated Channel(Ded-CH)
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Supplementary Channel(Sup-CH)
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The first subframe of the common direct mode frame is occupied by synchronization channel. All the HRMSs receives the synchronization signal on the Synchronization channel except HR-MSs transmitting the
synchronization signals. The HR-MSs are synchronized to the received synchronization signal if the signal
timing has priority to HR-MS’s synchronization timing itself. The details of timing priority is FFS. Some HRMSs sends the synchronization signal on the Synchronization channel at selected subframes. HR-MS selects its
slots for sending synchronization timing in distributed way. The details of how to select is FFS. The
synchronization channel is composed of two parts: synchronization channel preamble part and synchronization
channel message part. The synchronization channel preamble part is used for acquiring time and frequency
synchronization, and synchronization channel preamble part is used for transmitting some information including
frame structure information, hop count, transmitter ID et. al. The detailed design of synchronization channel is
discussed in [2].
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25
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Resources excluding the first subframe assigned for synchronization channel are assigned for dedicated
channels and supplementary channels. A Dedicated channel is a resource to send direct communication packets
for two HR-MSs or a group of HR-MSs. An HR-MS sends a packet on one or more than one subchannels of
dedicated channel and the other HR-MSs receives the packet on it. If two HR-MSs and a group of HR-MSs are
involved, the transmissions are unicast and multicast, respectively. How to configure the resource of dedicated
channel is discussed in [3]. The resources for dedicated channel is divided into small size sub-blocks (mRB:
mini-Resource Block), as shown in Figure 3. One mRB is composed of 6 subcarriers-by-6 OFDM symbols, and
a dedicated subchannel is composed of a collection of nine mRBs distributed across the entire frequency region.
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IEEE C802.16n-11/0130r1
Super frame
Super frame
CDMZ
CDMZ
Super frame
CDMZ
1
2
mRB
3-3
mRB
3-4
mRB
3-5
mRB
3-6
mRB
3-7
mRB
3-8
mRB
3-9
mRB
3-10
mRB
3-11
mRB
3-12
mRB
4-3
mRB
4-4
mRB
4-5
mRB
4-6
mRB
4-7
mRB
4-8
mRB
4-9
mRB
4-10
mRB
4-11
mRB
4-12
mRB
5-3
mRB
5-4
mRB
5-5
mRB
5-6
mRB
5-7
mRB
5-8
mRB
5-9
mRB
5-10
mRB
5-11
mRB
5-12
mRB
6-3
mRB
6-4
mRB
6-5
mRB
6-6
mRB
6-7
mRB
6-8
mRB
6-9
mRB
6-10
mRB
6-11
mRB
6-12
subframe
time
time
frequency
mRB
2-3
mRB
2-4
mRB
2-5
mRB
2-6
mRB
2-7
mRB
2-8
mRB
2-9
mRB
2-10
mRB
2-11
mRB
2-12
Slot 2
frequency
Sync-Ch preamble
Sync-Ch message
Slot 1
CDMZ
…
half-mRB
mRB (mini-resource block)
Figure 3. An example of common direct mode zone resource segmentation and construction of mRB
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A supplementary sub-channel is one-to-one mapped with each dedicated sub-channel. By using the
supplementary sub-channel, the following MAC messages, PHY signalings and short feedback messages related
with the corresponding dedicated subchannel are transmitted.
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- MAC messages: RTS, CTS, MCS information, ranging response et. al.
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- PHY signalings: periodic ranging sequence, sounding signal et. al.
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- Short feedback messages: ACK, NACK, CQI, CSI, RI (rank information) et. al.
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An mRB for supplementary sub-channel is divided into two half-mRB as shown in Figure 3, and a half mRB
is composed of 3 subcarriers-by- 5 OFDM symbols. Since all HR-MSs should listen the supplementary
channels, to obtain Tx. And Rx. Switching time, no signal is transmitted in the last OFDM symbol of
supplementary channel (6th OFDM symbol). The details of supplementary channel design are discussed in [3].
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4. References
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[1] IEEE C802.16n-11/0051r2, “Dedicated resources allocation for direct communications in IEEE 802.16n,” March 2011.
[2] IEEE C802.16n-11/0131, “Synchronization channels for talk-around direct communications,” July 2011.
[3] IEEE C802.16n-11/0132, “Dedicated channels and supplementary channels for talk-around direct communications,” July 2011.
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IEEE C802.16n-11/0130r1
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5. Proposed Text for the 802.16n Amendment Working Document (AWD)
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Note:
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The text in BLACK color: the existing text in the 802.16n Amendment Draft Standard
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The text in RED color: the removal of existing 802.16n Amendment Draft Standard Text
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The text in BLUE color: the new text added to the 802.16n Amendment Draft Standard Text
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[-------------------------------------------------Start of Text Proposal---------------------------------------------------]
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[Remedy1: Adapt the following change in Section 17.3.2.6 in the 802.16n AWD]
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17.3.2.6 Talk-around Direct Communication
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[note: This contribution provides text proposals for the following sections:
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17.3.2.6.2 Physical layer
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17.3.2.6.2.1 Frame structure
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17.3.2.6.2.2 Physical structure
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17.3.2.6.2.3 Control structure]
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17.3.2.6.2.1 Frame structure
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For talk-around direct communication, two types of infra-structure communication resources are dedicatedly
assigned:
19
20
-
Common Direct Mode Zone (CDMZ): set of PRUs with fixed size and positions which are commonly
assigned to all cells (must be CRU)
21
22
23
-
Cell Specific Direct Mode Zone (CSDMZ): additionally assigned direct-mode resource blocks
independently assigned by each HR-BS (CRU or DRU) and information to receive cell specific direct
mode region can be obtained from common direct mode zone
24
25
26
27
Figure xxx shows an example of talk-around direct communication resource allocation. In the figure, some
part of uplink infra structure resources are assigned for common direct mode zone, and some part of uplink and
downlink infra structure communication resources are assigned for cell specific direct mode zone. By assigning
the same physical resources for common direct mode zone the following benefits can be obtained:
28
29
-
Reduce the overhead of control channels to transmit allocation information of resources for direct-mode
communication
30
31
-
Reduce the computation complexity and power to obtain synchronization for direct communication,
specially for the HR-MSs in the outside of HR-BS coverage
6
IEEE C802.16n-11/0130r1
CSDMZ
cell-specific direct mode zone
common direct mode region
CSDMZ
CDMZ
CSDMZ
CSDMZ
cell-specific direct mode zone
common direct mode zone
CSDMZ
CDMZ
cell-specific direct mode zone
CSDMZ
cell-specific direct mode zone
CSDMZ
common direct mode zone
common direct mode zone
common direct mode zone
common direct mode zone
CSDMZ
CSDMZ
CSDMZ
CDMZ
CDMZ
CDMZ
Direct-mode S-preamble
Direct-mode P-preamble
1
2
Figure xxx. An example of talk-around direct communication resource allocation
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6
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The highest four PRUs of uplink resources are assigned for Common Direct Mode Zone (CDMZ). For FFT
size = 512, PRU 20, 21, 22, 23 are assigned for CDMZ, for FFT size = 1024, PRU 44, 45, 46, 47 are assigned
for CDMZ, and for FFT size = 2048, PRU 92, 93, 94, 95 are assigned for CDMZ. The resources for Cell
Specific Direct Mode Zone (CSDMZ) are determined by each HR-BS independently and the assignment
information is transmitted in the CDMZ.
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Logical frame of common direct mode zone is composed by collecting all resources of CDMZ in a
superframe as shown in Figure yyy. In the example, there are three uplink subframes for each 5msec frame.
Frame structure of cell specific direct mode zone is extension of common direct mode frame structure and the
details are FFS.
Super frame
Direct mode
zone
Super frame
Direct mode
zone
Slot 1
Super frame
Direct mode
zone
Direct mode
zone
Slot 2
subframe
13
14
Synchronization
Channel
Dedicated
Channel
Supplementary
Channel
Figure yyy. An example of common direct mode logical frame construction
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IEEE C802.16n-11/0130r1
1
2
There are three physical channels for talk-around direct communication:
3
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Synchronization Channel (Sync-CH)
4
-
Dedicated Channel(Ded-CH)
5
-
Supplementary Channel(Sup-CH)
6
7
8
9
10
11
12
13
14
15
16
17
The first subframe of the common direct mode frame is occupied by synchronization channel. All the HRMSs receives the synchronization signal on the Synchronization channel except HR-MSs transmitting the
synchronization signals. The HR-MSs are synchronized to the received synchronization signal if the signal
timing has priority to HR-MS’s synchronization timing itself. The details of timing priority is FFS. Some HRMSs sends the synchronization signal on the Synchronization channel at selected subframes. HR-MS selects its
slots for sending synchronization timing in distributed way. The details of how to select is FFS. The
synchronization channel is composed of two parts: synchronization channel preamble part and synchronization
message part. The synchronization channel preamble part is used for acquiring time and frequency
synchronization, and synchronization sequence part is used for transmitting some information including frame
structure information, hop count, transmitter ID et. al. The detailed design of synchronization channel is
described in 17.3.2.6.2.3.1
18
19
20
21
22
23
24
25
26
Resources excluding the first subframe assigned for synchronization channel are assigned for dedicated
channels and supplementary channels. A Dedicated channel is a resource to send direct communication packets
for two HR-MSs or a group of HR-MSs. An HR-MS sends a packet on one or more than one subchannels of
dedicated channel and the other HR-MSs receives the packet on it. If two HR-MSs and a group of HR-MSs are
involved, the transmissions are unicast and multicast, respectively. How to configure the resource of dedicated
channel is discussed in described in 17.3.2.6.2.3.2. The resources for dedicated channel is divided into small
size sub-blocks (mRB: mini-Resource Block), as shown in Figure zzz. One mRB is composed of 6 subcarriersby-6 OFDM symbols, and there are 12 mRBs for each subframe (4PRU/ 1/3 PRU = 12). A dedicated
subchannel is composed of a collection of 9 mRBs distributed across the entire frequency region in the slot.
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IEEE C802.16n-11/0130r1
Super frame
Super frame
CDMZ
CDMZ
Super frame
CDMZ
1
2
mRB
3-3
mRB
3-4
mRB
3-5
mRB
3-6
mRB
3-7
mRB
3-8
mRB
3-9
mRB
3-10
mRB
3-11
mRB
3-12
mRB
4-3
mRB
4-4
mRB
4-5
mRB
4-6
mRB
4-7
mRB
4-8
mRB
4-9
mRB
4-10
mRB
4-11
mRB
4-12
mRB
5-3
mRB
5-4
mRB
5-5
mRB
5-6
mRB
5-7
mRB
5-8
mRB
5-9
mRB
5-10
mRB
5-11
mRB
5-12
mRB
6-3
mRB
6-4
mRB
6-5
mRB
6-6
mRB
6-7
mRB
6-8
mRB
6-9
mRB
6-10
mRB
6-11
mRB
6-12
subframe
time
time
frequency
mRB
2-3
mRB
2-4
mRB
2-5
mRB
2-6
mRB
2-7
mRB
2-8
mRB
2-9
mRB
2-10
mRB
2-11
mRB
2-12
Slot 2
frequency
Sync-Ch preamble
Sync-Ch message
Slot 1
CDMZ
…
half-mRB
mRB (mini-resource block)
Figure zzz. An example of common direct mode zone resource segmentation and construction of mRB
3
4
5
6
A supplementary sub-channel is one-to-one mapped with each dedicated sub-channel. By using the
supplementary sub-channel, the following MAC messages, PHY signalings and short feedback messages related
with the corresponding dedicated subchannel are transmitted.
7
8
al.
9
10
- MAC messages: RTS, CTS for corresponding dedicated subchannel, MCS information, ranging response et.
- PHY signalings: periodic ranging sequence, sounding signal et. al.
- Short feedback messages: ACK, NACK, CQI, CSI, RI (rank information) et. al.
11
12
13
14
15
16
An mRB for supplementary sub-channel is divided into two half-mRB as shown in Figure zzz, and a half
mRB is composed of 3 subcarriers-by- 5 OFDM symbols. Since all HR-MSs should listen the supplementary
channels, to obtain Tx. And Rx. Switching time, no signal is transmitted in the last OFDM symbol of
supplementary channel (6th OFDM symbol). The details of supplementary channel design are discussed in
described in 17.3.2.6.2.3.3.
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[-------------------------------------------------End of Text Proposal----------------------------------------------------]
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