Handover Support for Femtocell Operation in m Document Number: IEEE C802.16m-09/2008 Date Submitted: Source: Inuk Jung Jin Ronny Yongho Kiseon LG Electronics Re:Call for comments for Letter Ballot 30 Venue:IEEE Session#63, Jeju Base Contribution: None Purpose: For member’s review and adoption into P802.16m_D1 Notice: This document does not represent the agreed views of the IEEE 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 Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

2 Motivation  AMS may Handover between CSG femtocells  HO for OSG femtocell BSs follow general HO procedure  CSG femtocell BSs cache/retrieve information of their CSG member AMSs. Also, CSG femtocell BSs share context of an AMS for fast network re-entry.  HO procedure among same CSG femtocell BSs can be simplified (i.e. CSG femtocells share AMS MAC context, operate at same FA etc.)  SOHO environment  A group of same CSG femtocell BSs are expected to be installed within an office  Active mobility is highly expected within an office or workplace.  Frequent HO expected within CSG femtocell network.

3 HO within CSG Femtocell network  Objective  Avoid frequent HO within CSG femtocells  Proposal  CSG femtocell may maintain an Active Set  AMS may omit network re-entry procedure when performing Anchor BS change to another femtocell of same CSG  Definitions  Active Set: A set of femtocell BSs belonging to the same CSG group. Geographically, the BSs in the Active Set are accessible by the AMS. BSs included in the Active Set may measure UL signals of AMSs (snooping). Also context (STID, Flow IDs, Security Context, DL/UL Allocation information) of the AMS is shared among those BSs  Anchor BS: The femtocell BS which the AMS is served by among the Active Set.

4 Active set management  Autonomous management  The CSG femtocells snoop nearby AMS  Any detected AMS’s are reported to the AMS’s anchor BS  The femtocell may form an active set based on the received snooping reports  AMS do not have to update its active set or send any measurement report to the BS

5 CSG Femto HO procedure  Since AMSs context is shared  Synchronization is expected to be good enough upon HO  Serving femtocell BS triggers HO  AMS may omit network re-entry procedure during HO execution at Action time

6 CSG Femto HO singaling procedure  Following procedure may be omitted  Scanning negotiation  AMS HO initiation & HO preparation  Network re-entry

Proposed text Remedy #1 On the 80216m_D1, page 489, line 60, adopt following modification of as follows Start of Text Support for Femto ABS General Description Femto ABS is intended to serve public users like an Open Subscriber Group (OSG), or to serve a Closed Subscriber Group (CSG), that is a set of subscribers authorized by the Femto ABS owner or the network service provider. CSG can be modified by the service level agreement between the subscriber and the network service provider. Femtocell ABSs of a same CSG group may share context of an AMS that is a member of that CSG group. Also, Femtocell ABSs may maintain an active set to allow enhance HO operation for CSG member AMS. An Active Set is a list of Femtocell ABS of a same CSG group and includes snooping reports of CSG member AMS that are detected End of Text Remedy #2 On the 80216m_D1, page 493, line 8, add following section to 15.4 as follows Start of Text Femto ABS Handover Femto ABS HO HO among CSG Femtocell ABSs Upon a HO to a CSG Femtocell ABS, the CSG Femtocell ABS may share AMSs context among other Femtocell ABS of the same CSG. If a CSG Femtocell ABS maintains an Active Set, the AMS may be directed to HO to a neighbor CSG Femtocell ABS with omission of network re-entry procedure End of Text