IEEE C80216m-09/1533
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed AWD Text on the Scheduling Procedure for Group Resource Allocation
Date
Submitted
2009-07-06
Source(s)
Jeongki Kim, Youngsoo Yuk, Kiseon Ryu,
Yongho Kim, Jin Sam Kwak
E-mail: {chegal, sixs, ksryu, ronnykim}@lge.com
LG Electronics
Re:
Category: AWD comments/Area: Chapter 15.2.8 (Group Resource Allocation)
“Comments on AWD 15.2.8 Group Resource Allocation”
Abstract
Proposed text on MAC procedure for Group Resource Allocation
Purpose
To be discussed and adopted by TGm for the 802.16m amendment.
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 discretion
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acknowledges and accepts that this contribution may be made public by IEEE 802.16.
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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>.
1
IEEE C80216m-09/1533
Proposed AWD Text on the Scheduling Procedure for Group Resource
Allocation
Jeongki Kim, Youngsoo Yuk, Kiseon Ryu, Yongho Ronny Kim, Jin Sam Kwak
LG Electronics.
Introduction
This contribution proposes the text on Scheduling procedure for Group Resource allocation section to be
included in IEEE 802.16m AWD.
References
[1] IEEE P802.16 Rev2/D8, “Draft IEEE Standard for Local and Metropolitan Area Networks: Air Interface
for Broadband Wireless Access,” Dec. 2008.
[2] IEEE 802.16m-07/002r7, “802.16m System Requirements”
[3] IEEE 802.16m-08/003r6, “The Draft IEEE 802.16m System Description Document”
[4] IEEE 802.16m-08/043, “Style guide for writing the IEEE 802.16m amendment”
2
IEEE C80216m-09/1533
Text proposal for inclusion in the 802.16m amendment
[Add the texts and figures marked in blue and remove the texts and figures marked in red in the IEEE
802.16m-09/0010r2]
------------------------------- Start of Proposed Text #1--------------------------------------------------[Remedy 2. Modify the texts in chapter 15.2.8.3.3 as follows:]
15.2.8.3.3 Bitmaps in Group Resource Allocation [TBD]
GRA uses of bitmaps to signal resource allocation information for usersAMSs within a group. These bitmaps are sent in the
Group Resource Allocation IE. The first bitmap is the User Bitmap which uses 1 bit per AMS to signal which users are
scheduled in the frame.
The second bitmap is MIMO Bitmap which areis used to indicate the assigned MIMO mode, when multiple MIMO
modes and SM parameters are supported in the group. The existence of second bitmap and the length of bits per
scheduled AMS are listed in Table 31 and Table 32.
MIMO
Mode Set
Existence
of second
bitmap
Table 31 – SecondMIMO Bitmap Information for DL
Length of bit
MIMO mode indication
per scheduled
AMS
0b00
No
-
OL SU-MIMO (SFBC with non-adaptive precoder)
0b01
Yes
1
0b0: OL SU-MIMO (SFBC with non-adaptive precoder)
0b1: OL SU-MIMO (SM with non-adaptive precoder) with Mt=2
0b10
No
-
CL SU-MIMO with Mt=1
0b11
Yes
1
0b0: CL SU-MIMO with Mt=1
0b1: CL MU-MIMO with Mt=1, Nt=2
MIMO
Mode Set
Existence
of second
bitmap
Table 32 – SecondMIMO Bitmap Information for UL
Length of bit
MIMO mode indication
per scheduled
AMS
0b00
No
-
OL SU-MIMO (SFBC with non-adaptive precoder)
0b01
Yes
1
0b0: OL SU-MIMO (SFBC with non-adaptive precoder) with Mt=2
0b1: OL SU-MIMO (SM with non-adaptive precoder) with Mt=2
0b10
No
-
OL MU-MIMO with Mt=1, TNS=2
0b11
Yes
1
0b0: CL SU-MIMO with Mt=1
0b1: CL MU-MIMO with Mt=1, TNS=2
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IEEE C80216m-09/1533
When MIMO Mode Set of the group contains MU-MIMO, PSI Bitmap and Pairing Bitmap are appeared to determine
AMS pair sharing same resource. PSI Bitmap uses 1 bit per scheduled AMS to indicate the assigned pilot stream
index(PSI).
Pairing Bitmap uses to indicate a pair of two AMSs using different PSI. The number of bits per pair in the Pairing Bitmap
depends on the total number of pairs in the group. If there are n pairs in the group, the number of bits per pair is p =
ceil[log2(n)]. The AMSs using PSI=0 is assigned an index starting from 0 to n – 1 in the same order in which they appear
in the bitmap. Every p bits in the pairing bitmap are assigned to the AMS using PSI=1 in the same order in which they
appear in the PSI Bitmap. These p bits carry the index of AMS with PSI=0 that is paired with corresponding AMS with
PSI=1.
The third bitmap is the Resource Allocation bitmap which uses n bits per AMS to signal MCS Burst Size and Resource Size
for the scheduled AMS in the subframe or extended subframe that are scheduled in the frame. The scheduled AMSs may
have different number of bits in the third bitmap when they are assigned different MIMO mode and SM parameter.
The bit length used for a scheduled AMS is determined by the total number of effective combinations for MCS and
resource size for the assigned MIMO mode with SM parameter. Effective combinations are derived by subtracting useless
combinations among all possible combinations. The following steps are needed to find the effective combinations.

Step 1: List all possible combination set C={ C(0,0), C(0,1), …, C(M,B) }
Table 33-Combination indexes
MCS/ HARQ data
burst size
1
2
…
B (Highest burst
size)
1
C(1,1)
C(1,2)
…
C(1,B)
2
C(2,1)
C(2,2)
…
C(2,B)
…
…
…
…
…
M (Highest MCS)
C(M,1)
C(M,2)
…
C(M,B)
C(m,b): Combination index for MCS m, HARQ data burst size b

Step 2: For each HARQ data burst size, useless combination is chosen when it requires same resource size with a lower MCS
level comparing to others due to the resource granularity. For b∈IB, m∈IM, n∈IM, and m>n,
{C(m,b)} U1 if N(m,b) = N(n,b)
Where
U1 : Useless combination set type 1
IM : Group MCS set
IB : Group HARQ burst size set
N(m,b) : Required number of RUs for MCS m, HARQ data burst size b

Step 3: For a given MCS, useless combination is chosen when it requires same resource size supporting a smaller HARQ data
burst size than others due to the resource granularity. For m∈IM, b∈IB, d∈IB, and b>d,
{C(m,b)} U2 if N(m,b) = N(m,d)
Where U2 is useless combination set type 2
4
IEEE C80216m-09/1533

Step 4: Derive effective combination set (E) which is
E = C-U1-U2
• Step 1: List all possible combination set C={ C(0,0), C(0,1), …, C(M,B) }
•
Step 1: List All possible combination set C={ C(0,0,0), C(0,0,1), … , C(I_sizeoffset, HARQ burst size,
Allocation size(NLRU)) }
– Group configuration IE includes
• I_sizeoffset information: Minimum I_size offset and Maximum I_sizeoffset
• HARQ burst size set
– AMS can get all possible allocation size based on I_sizeoffset and HARQ burst size set information
– AMS configures the combination table , C(I_sizeoffset, HARQ burst size, Allocation size(NLRU)), as
shown in Table 33
Table 33-Combination indices
HARQ
Allocation
size (NLRU)
Burst Size
I_sizeoffset
0
1
…
m (Highest value)
0 (lowest
value)
0 (highest
value)
C(0, 0, 0)
C(1, 0, 0)
…
C(m, 0, 0)
0
1
C(0,0, 1)
C(1, 0, 1)
…
C(m, 0, 1)
…
…
…
…
…
…
0
a (lowest
value)
C(0, 0, a)
C(1, 0, a)
…
C(m, 0, a)
1
0 (highest
value)
C(0,1, 0)
C(1, 0, 0)
…
C(m,1, 0)
1
1
C(0, 1, 1)
C(1, 1, 1)
…
C(m,1, 1)
…
…
…
…
…
…
n (highest
value)
z (lowest
value)
C(0, n, z)
C(1, n, z)
…
C(m, n, z)
C(m, n, z): Combination index for I_sizeoffset m, HARQ data burst size n, Allocation size z
Upon receiving a Group configuration A-MAP IE, an AMS can easily know the spectral efficiency value (Modulation Value (M) *
coding rate (R)) corresponding to all possible combinations as shown in table xx-1.
Table xx-1- Spectral efficiency values for all possible combination indices
HARQ
Allocation
size
Burst Size
(NLRU)
I_sizeoffset
1
…
m
value)
0 (lowest 0 (highest SE(0, 0, 0)
value)
value)
SE(1, 0, 0)
…
SE(m, 0, 0)
0
SE(1, 0, 1)
…
SE(m, 0, 1)
1
0
SE(0,0, 1)
5
(Highest
IEEE C80216m-09/1533
…
…
0
…
…
…
…
a
(lowest SE(0, 0, a)
value)
SE(1, 0, a)
…
SE(m, 0, a)
1
0 (highest SE(0,1, 0)
value)
SE(1, 0, 0)
…
SE(m,1, 0)
1
1
SE(0, 1, 1)
SE(1, 1, 1)
…
SE(m,1, 1)
…
…
…
…
…
…
SE(1, n, z)
…
SE(m, n, z)
n (highest z
(lowest SE(0, n, z)
value)
value)
SE(m,n,z): Spectral efficiency value for C(m, n, z)

Step 2: A Spectral efficiency (SE) difference value is used to reduce the RAB overhead. The SE difference value is delivered to
AMSs by Group configuration A-MAP IE. For each HARQ data burst size, efficient combinations are selected by using SE
difference as follows.
Initial SE: Lowest SE
E.g.) SE (0, 0, 0), SE (0, 1, 0), ……, SE (0, n, 0) for each HARQ burst size (n)
Last SE: Highest SE
E.g.) SE (m, 0, a), SE (m, 1, b), ……, SE (m, n, z) for each HARQ burst size (n)
For (i=Initial SE; i < last SE; i = Next SE) {
Next SE = MIN ({SE} >= i + SE difference)
{C(I, b, a)} -> U1, if i < {SE (I, b,a)} < Next SE
}
Where

b∈IB, I∈IM, a∈IA
U1: Useless combination set type 1
IM: Group I_SizeOffset set
IA: Group Allocation sizes (N_LRU), Depends on Group I_sizeoffset set and Group HARQ burst size set
IB: Group HARQ burst size set
SE (I, b, a ): Spectral efficiency value (M * R) for I_sizeoffset I, Allocation size(N_LRU) a, and HARQ
data burst size b
Step 3: Derive effective combination set (E) which is
E = C-U1
An index code is identified to each effective combination from lower MCS level and lower HARQ data burst size where n is
determined by Ceil{log2(Total number of effective combinations)}.
Examples of the utilizing bitmaps are shown in Figure 399-, Figure 400-, and Figure 401- and Figure 402-.
1
1
0
1
0
1
1
0
1
0
1
1
User Bitmap
0
0
1
1
1
1
Resource Allocation Bitmap
Figure 399–Example of Bitmaps with Group MIMO Mode Set: DL (0b00, 0b10), UL(0b00)
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IEEE C80216m-09/1533
1
1
0
1
1
0
1
0
1
0
1
0
0
1
User Bitmap
MIMO Bitmap
1
0
0
1
1
1
Resource Allocation Bitmap
Figure 400–Example of Bitmaps for Group MIMO Mode Set: DL (0b01), UL(0b01)
1
1
0
1
0
1
1
0
0
1
0
PSI Bitmap
(for MU-MIMO)
Pairing Pairing
ID: 00 ID: 01
1
0
1
1
User Bitmap
0
0
1
0
Pairing Bitmap
(for MU-MIMO with PSI=1)
Pairing
ID: 10
0
1
1
1
0
Resource Allocation Bitmap
for MU-MIMO
0
Figure 401–Example of Bitmaps for Group MIMOMode Set: UL(0b10)
7
IEEE C80216m-09/1533
1
1
0
1
0
1
1
0
1
1
0
1
0
1
PSI Bitmap
(for MU-MIMO)
0
1
Pairing
ID: 0
1
1
1
User Bitmap
MIMO Bitmap
0
Pairing Bitmap
(for MU-MIMO with PSI=1)
1
Pairing
ID: 1
0
1
1
1
0
0
Resource Allocation Bitmap
for MU-MIMO
Figure 402–Example of Bitmaps for Group MIMO Mode Set: DL(0b11), UL(0b11)
------------------------------- End of Proposed Text #1 --------------------------------------------------------------------------------- Start of Proposed Text #2 --------------------------------------------------[Remedy 2. Insert the below columns in Chapter 15.2.8.4.]
15.2.8.4 Error Handling Procedure
In the case of the addition of AMS to group, the ABS shall include HARQ Feedback Allocation for the A-MAP IE in the
Group configuration A-MAP IE. If an AMS successfully decodes the Group Configuration A-MAP IE, the AMS shall
transmit ACK via HARQ ACK/NACK channel indicated in the Group configuration A-MAP IE. Upon receiving the
HARQ ACK for the Group Configuration A-MAP IE, ABS shall start the group resource allocation using DL GRA
A-MAP IE or UL GRA A-MAP IE. In the absence (NULL detection) of an ACK for the Group configuration A-MAP IE,
the ABS shall assume that the corresponding AMS has not received the Group configuration A-MAP IE and the ABS
may transmit the Group configuration A-MAP IE again for fast group configuration.
In the case of the deletion of AMS from group, the ABS shall include HARQ Feedback Allocation for the A-MAP IE in
the DL/UL GRA A-MAP IE. If an AMS successfully decodes the DL/UL GRA A-MAP IE for the deletion of itself from
the group, the AMS shall transmit ACK via HARQ ACK/NACK channel indicated in the A-MAP IE. Upon receiving the
HARQ ACK for the GRA A-MAP IE, the ABS shall delete the AMS from the group and the corresponding AMS will
delete the parameters (e.g. User bitmap index, group ID, etc.) related to the group. In the absence (NULL detection) of an
ACK for the GRA A-MAP IE to delete AMS from the group, the ABS shall assume that the corresponding AMS has not
received the GRA A-MAP IE and the ABS may transmit the Group configuration A-MAP IE again for fast group
configuration.
------------------------------- End of Proposed Text #2 --------------------------------------------------------------------------------- Start of Proposed Text #3 --------------------------------------------------[Remedy 2. Insert the below texts and figures after Chapter 15.2.8.3.2]
8
IEEE C80216m-09/1533
15.2.8.3.3 Reconfiguration of User Bitmap Index
An ABS may reconfigure the User Bitmap indices of a group by sending the User Bitmap to AMSs.
15.2.8.3.3.1 ABS Operation
An ABS may reconfigure the User Bitmap indices of multiple AMSs in a subframe. To reconfigure the User Bitmap indices in a group,
an ABS shall include the User Bitmap in the Group Resource Allocation A-MAP IE. In the User Bitmap “1” indicates a scheduled
AMS or an unscheduled AMS in a group and “0” indicates an unused bitmap index or a deleted AMS. If the Shifting indicator is set to
1 and the retransmission flag is set to 0, the De-allocation bitmap consists of “0”s of User Bitmap or the length of De-allocated AMS
index is determined according to the number of “0”s of User Bitmap. Figure xx shows the example of the initial User Bitmap to
reconfigure the User Bitmap indices when there is de-allocated AMSs in a group. In Figure x, the bitmap indices of AMS #5 and AMS
#7 are shifted.
De-allocation
Bitmap
AMS
#1
AMS
#2
AMS
#3
AMS
#4
AMS
#5
AMS
#6
AMS
#7
AMS
#8
1
1
0
0
1
0
1
0
User Bitmap
0
1
0
1
0
0
1
Scheduled
User Bitmap
0
Figure xx: Example of an initial User Bitmap with De-allocation Bitmap
If the User Bitmap is retransmitted (i.e. retransmission flag == 1), the bitmap has the same structure as the previous User Bitmap of
the group and ABS shall include the ReTX Bitmap in Group Resource Allocation A-MAP IE to indicates which AMSs should shift
their indices at the frame. If the Shifting indicator is set to 1 and the retransmission flag is set to 1, the De-allocation bitmap consists of
“0”s of Scheduled User Bitmap or the length of De-allocated AMS index is determined according to the number of “0”s of Scheduled
User Bitmap. Figure xx shows the example of the User Bitmap retransmitted to reconfigure the User Bitmap indices when there are
de-allocated AMSs in a group.
AMS
#1
AMS
#2
AMS
#3
AMS
#4
AMS
#5
AMS
#6
AMS
#7
AMS
#8
1
1
0
0
1
0
1
0
User Bitmap
ReTx
Bitmap
1
0
1
0
0
1
Scheduled
User Bitmap
1
0
De-allocation
Bitmap
Figure xx: Example of a retransmitted User Bitmap with De-allocation Bitmap
9
IEEE C80216m-09/1533
After sending the shifting index information, the ABS shall wait for an ACK from the AMS.
15.2.8.3.3.2 AMS Operation
After decoding a Group Resource Allocation A-MAP IE including a User Bitmap, an AMS can know which AMSs should shift their
bitmap indices by scanning the User Bitmap. If an AMS finds that its bitmap index should be shifted, then the AMS shall shift its
bitmap index and the AMS shall send an ACK to the ABS for signaling that the AMS has successfully received the shifting
information. When an AMS receives the GRA A-MAP IE including the retransmitted User Bitmap (i.e. retransmission flag == 1), if
the AMS did not received the User Bitmap at the previous time, the AMS assumes that the AMS has lost the pervious GRA A-MAP IE
including User Bitmap and the AMS shall shift its bitmap index and send ACK to ABS via HARQ feedback channel. When an AMS
receives the GRA A-MAP IE including the retransmitted User Bitmap, if the AMS has received the User Bitmap successfully at the
previous time, the AMS shall not shift its bitmap index.
15.2.8.3.43 Bitmaps in Group Resource Allocation
------------------------------- End of Proposed Text #3 ---------------------------------------------------
10