1. 21-08-0120-00-0000 IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-08-0120-00-0000 Title: Handover Diagrams for Break before Make case Date Submitted: April 17, 2008 Authors or Source(s): Hongseok Jeon, Vivek Gupta, Junghoon Jee, Changmin Park Abstract: The handover diagrams for the break before make case are provided.

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3. 21-08-0120-00-0000 L.4.3 Mobile-initiated handover for Break before Make case - Description Figure L-7 shows a mobile-initiated handover flow chart for Proxy Mobile IPv6 (PMIPv6). In this case the MN looses its connectivity with the serving PoA before the target PoA can be notified of MN decision to handover. However, the MN discovers the target PoA, establishes connectivity with the target PoA and then the target PoA notifies serving PoA of handover completion. PMIPv6 signaling is then completed and the packets are then forwarded to MN's new location. The handover flow operates as follows: 1)MN receives packets through both Mobile Access Gateway (MAG) 1 located in the serving network and Local Mobility Anchor (LMA), which are primary components of the PMIPv6. 2)The MN queries the Information Server to get information about available neighboring networks. This information query can be attempted as soon as the MN attaches to a new serving network or periodically for refreshing the information. 3)MN sends the MIH_MN_HO_Candidate_Query Request message to the Serving PoS for triggering a mobile-initiated handover. This message contains requirements for potential candidate networks. 4)The Serving PoS sends the MIH_N2N_HO_Query_Resource Request messages to the informed Candi-date PoSs (can be more than one) in order to query the availability of the resource at the candidate networks. The Candidate PoS responds by sending the MIH_N2N_HO_Query_Resource Response message to the Serving PoS. The Serving PoS in turn sends MIH_MN_HO_Candidate_Query Response message to the MN. Finally, the MN decides the handover target based on the result of query about resource availability at the candidate networks.

4. 21-08-0120-00-0000 5)The MN unexpectedly looses connectivity with the serving PoS. Upon detecting MN's detachment, PMIPv6 client in the Serving PoS terminates a current binding of the MN via sending Proxy Binding Update with Lifetime set to 0 and requests LMA to buffer packets destined for the MN. 6)Once the MN establishes the layer 2 connection to the Target PoS, the PMIPv6 client as MIH User in the Target PoS registers the current MN's location to LMA by sending Proxy Binding Update message. LMA updates its Binding Cache Entry with the Proxy Binding Update message and then replies with Proxy Bind-ing Acknowledgement message. 7)After receiving the Proxy Binding Acknowledgement message, PMIPv6 clients sends Router Advertise-ment message to the MN. The Router Advertisement is constructed with the MN's information obtained from the policy server and LMA. It can be solicited by Router Solicitation message from the MN or periodically transmitted. MN configures IP addresses on its interface, which is currently used to connect to the Tar-get PoS, with the received Router Advertisement message. Once the PMIPv6 procedures are completed, MN receives packets through both MAG 2 and LMA. 8)After the PMIPv6 execution, the Target PoS sends the MIH_N2N_HO_Complete Request message to the previous Serving PoS. The previous Serving PoS responds the message with MIH_N2N_HO_Complete Response. L.4.3 Mobile-initiated handover for Break before Make case - Description (cont.)

5. 21-08-0120-00-0000 Other Network Resource Availability Check Information Query MAC- WiMAX MAC- WLAN MIHF MIH User UP Entity Mobile Node Serving Network (MAG1, WiMAX) MIH User (PMIPv6 Client) MIH User (PMIPv6 Client ) PoS- WiMAX PoA- WiMAX Other Network Candidate Network 1 (MAG2, WLAN) Candidate Network n (MAGn, WLAN) PoA- WLAN PoS- WLAN MIH User PoA-CnPoS-Cn LMA /AAA Server MIIS Server UP Entity PMIPv6-Domain Traffic flow b/w MN and Serving Network MIH_Get_Information Request MIH_Get_Information Response MIH_MN_HO_Candidate_Query Request MIH_MN_HO_Candidate_Query Response MIH_N2N_HO_Query_Resource Request MIH_N2N_HO_Query_Resource Response MIH_MN_HO_Candidate_Query.indication MIH_N2N_HO_Query_Resource.request MIH_N2N_HO_Query_Resource.indication MIH_N2N_HO_Query_Resource.confirm MIH_MN_HO_Candidate_Query.response MIH_N2N_HO_Query_Resource.response MIH_MN_HO_Candidate_Query.request MIH_Get_Information.request MIH_Get_Information.confirm Traffic flow b/w MAG1 and LMA Link Up Indication MIH_Link_Up.indication Link_Up.indication MIH_Link_Up.indication L.4.3 Mobile-initiated handover for Break before Make case Figure L-6

6. 21-08-0120-00-0000 Resource Release Higher Layer (PMIPv6) Handover Execution MAC- WiMAX MAC- WLAN MIHF MIH User UP Entity Mobile Node Serving Network (MAG1, WiMAX) MIH User (PMIPv6 Client) MIH User (PMIPv6 Client) PoS- WiMAX PoA- WiMAX Other Network Candidate Network 1 (MAG2, WLAN) Candidate Network n (MAGn, WLAN) PoA- WLAN PoS- WLAN MIH User PoA-CnPoS-Cn LMA MIIS Server UP Entity PMIPv6-Domain Proxy Binding Update Proxy Binding Acknowledgement Traffic flow b/w MN and Candidate Network1 Traffic flow b/w MAG2 and LMA MIH_N2N_HO_Complete Request MIH_N2N_HO_Complete Response Detect MN’s Attachment Update BCE and Forward Buffered Packets MIH_N2N_HO_Complete.indication MIH_N2N_HO_Complete.response MIH_N2N_HO_Complete.confirm MIH_N2N_HO_Complete.request (Router Solicitation) Router Advertisement Configure WLAN Interface L.4.3 Mobile-initiated handover for Break before Make case Figure L-6a