1. 21-06-xxxx-00-0000 IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-06-0630-00-0000 Title: The amendment for the MIH_Scan primitive Date Submitted: April, 20, 2006 Presented at IEEE 802.21 session #15 in San Diego Authors or Source(s): Liu Yuan, Dong Pei Ying Abstract: This contribution suggests some amendments to the primitive MIH_Scan. It extends the parameter Scan Request Sets for more request information. It also amends the parameter Scan Response Sets to provide more information for making handover decisions.

2. 21-06-xxxx-00-0000 IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) 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 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 802.21. The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> Section 6.3 of the IEEE-SA Standards Board Operations Manualhttp://standards.ieee.org/guides/opman/sect6.html#6.3 http://standards.ieee.org/board/pat/guide.html

3. 21-06-xxxx-00-0000 In the current draft, MIH_Scan is issued by upper layers to discover neighboring POAs. A MIH_Scan command may get information for more than one link type, and the parameter Scan Request Sets is defined as the link types (Section 8.5.3.7) that upper layers want to discover. It will be useful to extend the parameter Scan Request Sets for more information. The scan request can include three parts, Scan Link Identifier, Scan PoA Sets and Scan Command. The Scan PoA Sets is defined as a list of PoAs that upper layers expect to scan. Only the PoAs specified in the Scan PoA Sets are scanned and the scan results for them will report to upper layers. This may improve the efficiency of scanning. The Scan Command is the request command for the specified link and defined in related SDOs. The MIHF may carry this parameter to the link layer for media depended link scan. Background

4. 21-06-xxxx-00-0000 Amendment to the current draft MIH_Scan.request (Source Identifier, Destination Identifier, Scan Request Sets ) NameTypeValid RangeDescription Source IdentifierIdentifierAny valid individual or group identifier The identifier of entity where the request is initiated.The field may be optionally left empty if the command is local. Destination IdentifierIdentifierMIH_LOCAL MIH_REMOTE The destination identifier of request or response. This is the identifier of local or peer MIH Function. Scan Request SetsN/AList of scan request. The scan request includes the identifier of the link to scan, PoAs specified to scan and scan command for each link.

5. 21-06-xxxx-00-0000 NameTypeValid RangeDescription Scan Link IdentifierLINK IDN/AThe identifier of the specified link to scan. Scan PoA Sets (optional) N/AList of PoAs the upper layers expect to scan. If this parameter is null, all potential PoAs should be scanned. Scan Command (optional) N/AScan command for the specified link. This command can be media dependent and defined in related SDOs. The scan request can be composed of the three parts as follows. The address of specified PoA in Scan Link Identifier must be null. Amendment to the current draft The information of PoA as the element in Scan PoA Sets is defined as follows: NameTypeValid RangeDescription LINK_IDLINK IDN/AThe identifier and address of PoA specified to scan.

6. 21-06-xxxx-00-0000 Background In 802.21, heterogenous network handovers can be initiated by terminal or network, and the initiator of handover should know the parameters of radio environment around the terminal, such as the addresses and signal strength of the PoAs that terminal can detect. Without these information, the initiator can’t select the proper candidates for handover. For an example, in GSM system, handover between different cells is initiated and controlled by BSC and terminal provides information for assistance. The terminal measures the parameters of radio environment of its neighboring cells and reports the results to the serving BSC periodically. The BSC makes the handover decision according to these reports and initiates the handover to the terminal and MSC.

7. 21-06-xxxx-00-0000 Background UMA system is also an example. During the handover from UMAN (Unlicensed Mobile Access Network), MN will send a URR HANDOVER REQUIRED message to the network including the list of target cell identifiers and the received signal strength of each cell. Currently there is no right way for initiators of handover to get dynamic radio information of terminal. The Link_Parameters_Change, MIH_Get_Status or MIH_Link_Parameters_Report can only report the parameters of the current link or links that have been established. The MIH_Scan response is only used to get the potential PoAs’ address information and can not provide dynamic radio environment parameters such as signal strength (Section 8.5.3.8). So it is necessary to extend MIH_Scan response to provide more information for making handover decision.

8. 21-06-xxxx-00-0000 Background An another problem is the MIH_Scan response can only report the PoAs scanned, not including the PoAs that can not be detected. Network may need to know that the terminal has moved out from some PoAs’ coverage areas and can not listen to beacons, so it will not consider these PoAs when choosing handover candidates.

9. 21-06-xxxx-00-0000 Amendment to the current draft MIH_Scan.response (SourceIdentifier, DestinationIdentifier, Scan Response Sets, Scan Not Detect Sets) NameTypeValid RangeDescription Source IdentifierIdentifierAny valid individual or group identifier The identifier of entity where the request is initiated. This field may be optionally left empty if the command is local Destination IdentifierIdentifierMIH_LOCAL MIH_REMOTE The destination identifier of request or response. This is the identifier of local or peer MIH Function Scan Response SetsN/AList of scanned PoAs and related information. Scan Not Detect SetsN/AList of PoAs that exist in the previous scan but can not be detected in the current scan.

10. 21-06-xxxx-00-0000 The information of detected PoAs may include the static and dynamic parts as follows: Amendment to the current draft NameTypeValid RangeDescription LINK_IDLINK IDN/AThe identifier of the scanned link. SIGNAL_STRENGTHIntegerN/AThe signal strength of the scanned PoA. Extended Information (optional) N/AThe extended media dependent information defined in related SDOs. The parameter Scan Not Detect Sets represents the sets of PoAs’ information that exist in the previous scan but can not be detected in the current scan. The PoA’s information are as follows: NameTypeValid RangeDescription LINK_IDLINK IDN/AThe link type and address of the PoA that exists in the previous scan but can not be detected in the current scan