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Modifications for location update process when mitigating between a CSG-closed Femto ABS and a multiple-FA supporting Macro ABS

IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number:

IEEE C802.16m-09/1740Date Submitted:

2009-08-29Source:

Chie Ming Chou, Chun-Yen Wang, Frank Ren, Jung-Mao Lin, Yung-Han Chen chieming@itri.org.twITRIWern Ho Sheen whsheen@itri.org.twChaoyang University of Technology / ITRI

Venue:Re : IEEE 802.16m-09/0028r1: “802.16m/D1 letter ballot document”

Target topic: P802.16M/D1 - 15.4.9.1

Purpose:Modify the location update process to support idle mode

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.

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Background

• A multi-FA supporting ABS may not broadcast all paging message on all carriers– The paging message may be transmitted only on one carrier– The distribution of paging message in an ABS may not be the same as

another ABS

• A CSG-closed Femto ABS may support only one FA– A CSG-closed Femto ABS could use the same FA or different FA with

overlapped Macro ABS

• There are 4 possible scenarios when an AMS mitigates between accessible CSG-closed Femto ABS and overlapped Macro ABS

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Scenario 1 (CSG-closed Femto ABS supports different PGID with overlapped Macro ABS)

• No matter same or different FA used by a CSG-closed Femto ABS, an AMS needs to perform location update process when moving between an overlapped Macro ABS and CSG-closed Femto ABS– Cause frequent location update process – No modifications are needed for location update process

Macro ABS (FA1,FA2,FA3)

AMS1

Femto ABS (FA4)

SFH

SFH

SFH

FA1

FA2

FA3

SFH

PGID 4

PGID1

PGID2

PGID3

FA4

Scenario 1

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Scenario 2 (CSG-closed Femto ABS supports different FA with same PGID from overlapped Macro ABS)

• When moving from Macro ABS to CSG-closed Femto ABS– Do the cell reselection and find supporting the same PGID

• Continue listening the paging message in paging listening interval

• When moving from CSG-closed Femto ABS to Macro ABS– Do the cell reselection and may find supporting different PGID in this new FA

• Ex: AMS1 belongs to PGID2, reselect to FA1 and find it only supports PGID1

– AMS will perform location update even other FA supports original PGID• It is a waste to re-assign a new PGID• A modified location update process can resolve this problem (see P5)

Macro ABS (FA1,FA2,FA3)Femto ABS (FA4)

SFH

SFH

SFH

FA1

FA2

FA3

SFH

PGID1,2,3

PGID1

PGID2

PGID3

FA4

AMS1

Scenario 2

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Proposal: Modified location update process

• When an AMS sends AAI_RNG-REQ to request location update, a multiple-FA supporting ABS can determine whether other FAs support this AMS’s original PGID– If no FA support this AMS’s PGID, ABS will notify paging controller and

give AAI_RNG-RSP with new paging information– If one FA support this AMS’s PGID, ABS will give AAI_RNG-RSP with

corresponding physical carrier index to facilitate AMS reselect to this FA

• The notification and re-assignment between paging controller and ABS does not need

• Speedup the location update process

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Scenario 3 (CSG-closed Femto ABS supports same FA with same PGID from overlapped Macro ABS)

• When moving from Macro ABS to CSG-closed Femto ABS– Do the cell reselection and find supporting the same PGID

• Continue listening the paging message in paging listening interval

• When moving from CSG-closed Femto ABS to Macro ABS– Do the cell reselection and may find supporting different PGID in new FA

• Ex: (1) AMS1 goes into idle mode from Macro ABS’s FA2 and be assigned the PGID2 (2) When moving to CSG-closed Femto ABS, reselect FA1 and find supporting same PGID (3) When moving to Macro ABS, reselect to FA1 and find supporting different PGID

– AMS will perform location update even other FA supports the original PGID• Modified location update process can be applied

Macro ABS (FA1,FA2,FA3)Femto ABS (FA1)

SFH

SFH

SFH

FA1

FA2

FA3

SFH

PGID1,2,3

PGID1

PGID2

PGID3

FA1

AMS1

Scenario 3

(1)

(2)

(3)

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Scenario 4 (CSG-closed Femto ABS supports same FA with partial PGID from overlapped Macro ABS)

• When moving from Macro ABS to CSG-closed Femto ABS– Do the cell reselection and may find supporting different PGID

• Ex: AMS1 camps on FA2 and belongs to PGID2• AMS will perform location update after reselecting FA1

• When moving from CSG-closed Femto ABS to Macro ABS– Do the cell reselection and almost reselect the same FA

• Find supporting the same PGID • Continue listening the paging message in paging listening interval

Macro ABS (FA1,FA2,FA3)Femto ABS (FA1)

SFH

SFH

SFH

FA1

FA2

FA3

SFH

PGID1

PGID1

PGID2

PGID3

FA1

AMS1

Scenario 4

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Conclusion• The original location update process can be applied in

scenario 1,4• Modified location update process can facilitate the idle mode

support in scenario 2,3– When an AMS moves out a Femto ABS and detects that the new

preferred ABS does not support its paging group, the AMS shall perform location update. The new preferred ABS may respond the AMS with the physical carrier index of another carrier if the AMS’s paging group is supported on that carrier

• by adding new TLV in AAI_RNG-RSP

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Proposed text[Add the following text in section 15.4.9.1]15.4.9.1 idle mode

When an AMS moves out a CSG-closed Femto ABS and detects that the new preferred ABS does not support its paging group, the AMS shall perform location update. The new preferred ABS may respond the AMS with the physical carrier index of another carrier if the AMS’s paging group is supported on that carrier

[Modify the text in table 683]15.2.6.2 AAI_RNG-RSP

Table 682—parameters for AAI_ RNG-RSP

Name Value Usage

Location Update Response 0x00=Success of Location Update0x01=Failure of Location Update0x02=Reserved0x02=Carrier change0x03=Success of location update and DL traffic pending0x04~0xFF: Reserved

It shall be included when an ABS sends an AAI_RNG-RSP message in response to an AAI_RNG-REQ message used to perform location update

Target carrier index Target carrier index for supporting original PGID It shall be included only if the Location Update Response is set to 0x02

Paging Information New Paging Information assigned to AMS It shall be included only if the Location Update Response is set to 0x00 (Success of Idle Mode Location Update) and the Paging Information has changed