IEEE C802.16m- 10/0521r1
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed text for E-MBS operation for carrier switching mode (16.2.3/16.9.2.2)
Date
Submitted
2010-05-10
Source(s)
Jeongki Kim, Youngsoo Yuk, Kiseon Ryu,
E-mail: jeongki.kim@lge.com,
youngsoo.yuk@lge.com,
kiseon.ryu@lge.com
Jin Sam Kwak
LG Electronics
Re:
Comments on IEEE P802.16m/D5 for IEEE 802.16 WG Letter Ballot Recirc #31a
Abstract
This contribution proposes the texts related to carrier switching mode for E-MBS.
Purpose
To be adopted by TGm for the 802.16m Amendment.
Notice
Release
Patent
Policy
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The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution,
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<http://standards.ieee.org/board/pat>.
1
IEEE C802.16m- 10/0521r1
Proposed text for E-MBS operation for carrier switching mode
(16.2.3/16.9.2.2)
Jeongki Kim, Youngsoo Yuk, Kiseon Ryu, Jin Sam Kwak
LG Electronics
1. Introduction
E-MBS service may be provided by the specific carrier that is not AMS’s primary carrier and an E-MBS AMS
with only one transceiver (i.e., AMS operating Carrier switching mode) in connected state switches from its
primary carrier to the alternative carrier in order to receive E-MBS data bursts, E-MBS configuration message
and E-MBS MAP and switches from the alternative carrier to primary carrier in order to receives the unicast
scheduling from the ABS. According to D5, the E-MBS AMS performs the carrier switching operation based on
E-MBS subscription information of the AMS (E-MBS connection information (i.e., MSTIDs+FIDs) that is
allocated to the AMS during DSA procedure.
In real E-MBS environment, basic(default) E-MBS channels are allocated to all AMSs that subscribe E-MBS
and the number of basic E-MBS channels is much more than that of special E-MBS channels. In this case the
carrier switching method based on the E-MBS subscription information will result in the following problems.
 Restricted unicast scheduling: The ABS will allocate the unicast resource to AMS subscribing E-MBS
during the short and specific period because the ABS cannot know the activated channel information of
the AMS as shown in Figure 1.
E-MBS
carrier
MSI
Primary
carrier
E-MBS MAP
Bursts for default E-MBS
channels/connections
Bursts for special
channels/connections
Unicast scheduling
period for AMSs with
only basic channels
Figure 1

It will also increase the possibility of collision between E-MBS allocations and a certain periodic
allocation (e.g. persistent scheduling) especially.
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IEEE C802.16m- 10/0521r1
 If an AMS subscribes all channels (i.e., the AMS is a premium user in E-MBS), the unicast service
cannot be provided with the AMS until the AMS leaves E-MBS.
2. Proposal
A Carrier Switching-enabled AMS receiving E-MBS can know its activated E-MBS channel information from
application layers (this is implementation issue of AMS and is out of scope in this specification) and the AMS
notifies the ABS of the E-MBS connection information (i.e., MSTIDs+FIDs) related to its activated E-MBS
channels whenever the activated E-MBS connection changes. The channel change by user does not happen
frequently (e.g., more than several ten minutes) and in the worst case it happens per several seconds. Therefore
the report of channel change by Carrier Switching-enabled AMS is not a big overhead. The AMS reports the
start/termination of E-MBS reception. When the Carrier Switching-enabled AMS starts the reception of E-MBS,
the AMS reports the activated E-MBS connection information to ABS. In case of the termination of E-MBS
reception the AMS will not switch from primary carrier to E-MBS carrier and ABS can allocate the unicast
resource to the AMS in a whole primary carrier.
Table 1 shows the AAI_E-MBS-REP message format.
Table 1 –AAI_E-MBS-REP message format
Syntax
Size
Notes
(bit)
AAI_E-MBS-REP_Message_Format()
{
MAC Control Message Type
8
AAI_E-MBS-REP
Action Code
2
0b00: E-MBS reception initiation
0b01:
E-MBS
reception
termination
0b10: E-MBS Connection Change
0b11: reserved
If (Action code == 0b00||Action Code
== 0b10) {
Num_E-MBS_Connections
4
The number of the currently
receiving E-MBS connections.
for
(i
=
0;
Num_E-MBS_Connections; i++) {
E-MBS ID + FID
16
E-MBS connections (E-MBS IDs +
FIDs) which the AMS receives
currently
i<
}
}
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IEEE C802.16m- 10/0521r1
E-MBS
carrier
MSI
MTI
MTS Type =
0b00 for
AMS1
UTI
SG
SG
MTS Type =
0b01 in AMS1
MTS Type =
0b10 in AMS2
E-MBS bursts
E-MBS burst
based on
of AMS_1
subscriptions
* SG: Switching Gap, MTS: MulTi-carrier Switching
E-MBS
MAP
E-MBS
region
E-MBS burst
of AMS_2
Unicast Traffic
Interval (UTI)
E-MBS Traffic
Interval (MTI)
Figure 2
An ABS shall transmit the AAI_E-MBS-RSP message to the E-MBS AMS in response to the reception of
AAI_E-MBS-REP. The Multi-carrier switching type field in AAI_E-MBS-RSP message is available only when
the AAI_E-MBS-RSP message is a response to AAI_E-MBS-REP message with Action Code == 0b00 and it
will set to 0b11 when Action Code in AAI_E-MBS-REP message is not 0b00.
Table 2 –AAI_E-MBS-RSP message format
Syntax
Size
Notes
(bit)
AAI_E-MBS-RSP_Message_Format()
{
MAC Control Message Type
8
AAI_E-MBS-RSP
Multi-carrier switching type
2
Indicates the type of switching from E-MBS
carrier to AMS’s primary carrier.
- 0b00: Switching after all E-MBS allocation in a
MSI. AMS will not report the changed E-MBS
connection information to ABS when the
receiving E-MBS connections are changed.
- 0b01: AMS switches to a primary carrier after
receiving E-MBS MAP and E-MBS bursts for
the AMS
- 0b10: AMS switches to a primary carrier after
receiving E-MBS MAP, switches to a E-MBS
carrier in order to receive E-MBS burst, and
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IEEE C802.16m- 10/0521r1
switches to a primary carrier after receiving
E-MBS burst
0b11: reserved
}
3. References
[1] IEEE P802.16m/D5, “DRAFT Amendment to IEEE Standard for Local and metropolitan area networks”
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IEEE C802.16m- 10/0521r1
4. Text proposal for the 802.16m DRAFT amendment
---------------------------------------------------------Start of the Proposed Text --------------------------------------------------------[Remedy #1: Modify “16.9.2.2 E-MBS Operation in Connected State” section as follows:]
16.9.2.2 E-MBS Operation in Connected State
When an AMS moves across E-MBS zone boundaries in Active Mode or Sleep Mode, the AMS performs the
handover procedure described in 16.2.6.3.
When the AMS transits to a new E-MBS Zone while in Active Mode or Sleep Mode, and the E-MBS service
flow management encodings of the AMS have not been updated, the AMS shall send AAI_RNG-REQ message
with Ranging Purpose Indication Bit#4 is set to 1 at the target ABS and the ABS shall include MSTID and FID
Update in AAI_RNG-RSP parameters to provide updated service flow management encodings for any affected
E-MBS flow as part of the handover procedure.
Once an AMS has received the E-MBS allocation information in the E-MBS-MAPs, it may not listen to the
downlink channels till the next transmission of desired E-MBS flow or the next E-MBS-MAP.
When EMBS data is transmitted on an alternative carrier, i.e. other than the AMS’s primary carrier where
service flows are configured the AMS is redirected to relevant carrier through DSA as described in 16.9.2.1.
During the transmission of EMBS configuration messages and the EMBS data to which AMS is subscribed, the
AMS with only one transceiver may not be available for signaling exchange with ABS on the primary carrier.
The AMS with multiple transceivers may be able to receive EMBS data while communicating with ABS on
primary carrier.
Other EMBS operations in idle and connection states as described in 16.9.2.2 and 16.9.2.3 also applicable to
this scenario.
The AMS does monitor down link channels and follow the entire idle mode and connected mode procedures as
required by other services. While receiving E-MBS data, the AMS may temporary interrupt the reception of
E-MBS packets for any reason, e.g. if time critical scanning is needed, without notifying the ABS.
16.9.2.2.1 E-MBS Operation for Multi-carrier switching support in Connected State
An AMS operating in multi-carrier switching mode shall inform ABS of the start (Action code == 0b00) or
termination (Action code == 0b01) of the E-MBS reception via AAI_E-MBS-REP message.
An ABS shall transmit the AAI_E-MBS-RSP message in response to the reception of AAI_E-MBS-REP.
In multi-carrier switching mode, several MTIs (E-MBS Traffic interval) and UTIs (Unicast Traffic interval) are
repeated, and an AMS shall connect to the primary carrier during UTI. Between two intervals, switching gap
with a length of one subframe shall be located.
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IEEE C802.16m- 10/0521r1
If multi-carrier switching type is set to 0b00, UTI of an AMS starts at the end of all E-MBS bursts for E-MBS
connections (E-MBS IDs and FIDs) allocated to the AMS during DSA procedure and ends at the beginning of
MSI. In this type the AMS is not required to transmit AAI_E-MBS-REP message when the E-MBS connections
that the AMS currently receives are changed.
If multi-carrier switching type is set to 0b01, UTI of an AMS starts at the end of all E-MBS bursts for the
E-MBS connections (E-MBS IDs and FIDs) included in AAI_E-MBS-REP message and ends at the beginning
of MSI. If multi-carrier switching type is set to 0b10, one UTI of an AMS starts at the end of E-MBS MAP and
ends at the beginning of E-MBS burst for the E-MBS connections (E-MBS IDs and FIDs) included in
AAI_E-MBS-REP message and the other UTI of the AMS starts at the end of all E-MBS bursts for the E-MBS
connections (E-MBS IDs and FIDs) included in AAI_E-MBS-REP message and ends at the beginning of
E-MBS MAP. If multi-carrier switching type is set to 0b01 or 0b10, the AMS is required to transmit
AAI_E-MBS-REP message with the list of the E-MBS connections whenever the E-MBS connections that the
AMS currently receives are changed.
Figure xx shows an example of carrier switching of E-MBS AMS according to multi-carrier switching type.
E-MBS
carrier
MSI
MTI
MTS Type =
0b00 for
AMS1
UTI
SG
SG
MTS Type =
0b01 in AMS1
MTS Type =
0b10 in AMS2
E-MBS bursts
E-MBS burst
based on
of AMS_1
subscriptions
* SG: Switching Gap, MTS: MulTi-carrier Switching
E-MBS
MAP
E-MBS
region
E-MBS burst
of AMS_2
Unicast Traffic
Interval (UTI)
E-MBS Traffic
Interval (MTI)
Figure xx. Switching of E-MBS AMS according to multi-carrier switching type
If the Action Code in AAI_E-MBS-REP indicates the E-MBS connection change (0b01), then the AMS shall
perform the carrier switching operation based on the currently receiving E-MBS connection information
included in AAI_E-MBS-REP and the ABS shall allocate the unicast resource to AMS at a primary carrier
based on the E-MBS connection information included in AAI_E-MBS-REP. If the Action Code in
AAI_E-MBS-REP indicates the termination of E-MBS reception (0b10), then the AMS does not switches to
E-MBS carrier any longer and the ABS is able to allocate the unicast resource to AMS on a primary at all time.
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IEEE C802.16m- 10/0521r1
[Remedy #2: Add the following sections at the end of Section 16.2.3:]
16.2.3.xx AAI_E-MBS-REP (E-MBS report) message
The AMS shall transmit the AAI_E-MBS-REP message in order to report the start or termination of E-MBS
reception. The AMS may transmit the AAI_E-MBS-REP message in order to inform the ABS of the
information on the currently receiving E-MBS connections.
Table xxx –AAI_E-MBS-REP message
M/O
Attributes/Array of attributes
Size
(bits)
Value/Notes
M
MAC Control Message Type
8
AAI_E-MBS-REP message
M
Action code
2
0b00: E-MBS reception initiation
0b01: E-MBS reception termination
0b10: E-MBS Connection Change
0b11: reserved
O
Num_E-MBS_Connections (n)
4
The number of the currently receiving E-MBS Present
when
the
connections.
Action code is set to
0b00 or 0b10
O
E-MBS IDs and FIDs
Variable
E-MBS connections (E-MBS IDs + FIDs)
which the AMS receives currently.
Conditions
Present when the
Action code is set to
0b00 or 0b10
16.2.3.xx AAI_E-MBS-RSP (E-MBS response) message
An ABS shall transmit the AAI_E-MBS-RSP message to the E-MBS AMS in response to the reception of
AAI_E-MBS-REP. The Multi-carrier switching type field in AAI_E-MBS-RSP message is available only when
the AAI_E-MBS-RSP message is a response to AAI_E-MBS-REP message with Action Code == 0b00 and it is
ignored when the Action Code in AAI_E-MBS-REP message is not 0b00.
Table yyy –AAI_E-MBS-RSP message format
M/O
Attributes/Array of attributes
Size
(bits)
Value/Notes
M
MAC Control Message Type
8
AAI_E-MBS-RSP message
M
Multi-carrier switching type
2
Indicates the type of switching from E-MBS
carrier to AMS’s primary carrier.
- 0b00: Switching after all E-MBS allocations for
E-MBS connections (E-MBS IDs and FIDs)
allocated to the AMS during DSA procedure. The
AMS shall not report the changed E-MBS
connection information to ABS when the
receiving E-MBS connections are changed.
- 0b01: AMS switches to a primary carrier after
8
Conditions
IEEE C802.16m- 10/0521r1
receiving E-MBS MAP and E-MBS bursts for the
AMS
- 0b10: AMS switches to a primary carrier right
after receiving E-MBS MAP, switches to a
E-MBS carrier in order to receive E-MBS burst,
and switches to a primary carrier right after
receiving E-MBS burst
0b11: reserved
-----------------------------------------------------------End of the Proposed Text
9
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