1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN:21-06-0689-00-0000 Title: IE Use Cases Date Submitted: July 14, 2006 Presented at IEEE 802.21 session in San Diego Authors or Source(s): Subir Das and Yoshihiro Ohba Abstract: This document describes the use case scenarios for LB1 comment # 324.

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3. LB1 Comment #324 In general, it is not clear from the current draft how this information could be used/why some IEs are useful etc. The draft would benefit from more descriptive text to aid understanding of why certain pieces of information are useful (e.g. in some sort of more detailed informative section).

4. Suggested Remedy Adopt the use case scenarios in this document and add them as informative section in the current draft

5. Scenario #1 Proactive Handover Optimization using Information Service –In this scenario, a mobile station has two interfaces (e.g., Wi-Fi and Cellular access) and connected to cellular network. While roaming to a particular location, mobile station experiences a poor network connectivity and its policy indicates to switch to a Wi-Fi interface if the network is available. However, due to power management, it does not allow to power on the Wi- Fi interface and explore the availability of Wi Fi networks as an ad hoc fashion. Instead, mobile station uses the MIH Information Service to obtain the neighbouring network information. In order to obtain the such information, mobile station uses MIH IS primitives to query the information server using Information Elements (IEs) such as Type_IE_Network, Type_IE_Operator_ID, etc via the cellular network. Mobile station then uses these information for making intelligent handover decision and network selection. Figure below describes a sequence of example message flows that can typically happen while a mobile station performs a proactive (make – before-break) handover for mobility optimization.

6. MIH_Get_Info_Request_Frame MIH_Get_Info_Response_frame MIH_Get_Info.request [InfoQuerytype: TLV Infoqueryparameters: TYPE_IE_LIST_OF_NETWORKS] MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: LinK_Type= WLAN [19]] Satus: 1 Power on WLAN MIH_Get_Info.confirm linK_Detected_Indication MIH_Get_Info.request [InfoQuerytype: TLV Infoqueryparameters: TYPE_IE_OPERATOR_ID] MIH_Get_Info_Request_Frame MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: OPERATOR_ID=XYZ Satus: 1] MIH_Get_Info.confirm Local MIHF Local MIHF User Remote MIHF User Remote MIHF MIH_Event_Indication MIH_Get_Info_Response_Frame Mobile Assisted handover MIH_Handover_Initiate _Indication MIH_Handover_Initiate _Request CurrentLinkType = 3G HandoverAck = 1 (Initiate Handover) PreferredLinkType = WLAN PreferredPoA = MAC of AP MIH_Handover_Prepare (?) MIH_Link_Detected_Frame MIH_Link_Detected_Indication MIH_Handover_Initiate_Request_Frame [LinkType = WLAN POA MAC Address=ABC Network Identifier= Operator ID] Figure 1: Proactive Handover Message Flows using IS MIH_Handover_Prepare_confirm

7. CurrentLinkType = 3G NewLinkType = WLAN NewPoA = MAC of AP(x) CurrentLinkAction = LINK_NO_ACTION MIH_Handover_initiate_Response_Frame MIH_Handover_Commit_Request_frame MIH_Handover_Initiate _Response MIH_handover_intiate _confirm MIH_Handover_commit _request MIH_Handover_Commit _Indication CurrentLinkType = 3G HandoverAck = 1 (Initiate Handover) PreferredLinkType = WLAN PreferredPoA = MAC of AP(x ) New Link establishment MIH_Handover_Commit _Response MIH_Handover_Complete_Request_Frame MIH_handover_Commit _confirm CurrentLinkType = 3G CurrentLinkAction = Link_low_Power NewLinkType=WLAN POA Address= ABC Handover Status = 1 ( Handover Performed) Mobility management Signaling MIH_Switch MIH_Handover_Complete _Request MIH_handover_Complete _Indication MIH_handover_Complete _Response MIH_Handover_Complete_Request_Frame MIH_Handover_Complete _Confrim Local MIHF Local MIHF User Remote MIHF User Remote MIHF Contd. Figure 1 : Proactive Handover Message Flows using IS

8. Scenario #2 Proactive Handover Optimization using Information Service –In this scenario, a mobile station has three interfaces (e.g., Wi-Fi, WiMAX, and Cellular access) and is connected to a cellular network. While roaming to a particular location, mobile station has experienced a poor network connectivity and its policy indicates to switch to a Wi-Fi and WiMAX s respectively. As described in scenario 1, mobile station uses the MIH Information Service to obtain the neighbouring network information first before powering on the other interface. Mobile station uses MIH IS primitives to query the neighbouring network information using IEs such as, Type_IE_Network, Type_Operator_ID, Type_Roaming_Partner, etc. via the cellular network. Since the mobile stations policy has preference on Wi-Fi network, it powers on the Wi-Fi interface first but with a subsequent query mobile station learns that Wi-Fi network is not a roaming partner. It then powers on the Wi-MAX interface and uses other information for making intelligent handover decision and network selection. Figure below describes a sequence of example message flows that can typically happen while a mobile station performs a proactive (make –before-break) handover for mobility optimization.

9. MIH_Get_Info_Request_Frame MIH_Get_Info_Response_frame MIH_Get_Info.request [InfoQuerytype: TLV Infoqueryparameters: TYPE_IE_LIST_OF_NETWORKS Location: (X,Y)] MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: LinK_Type= WLAN [19], WiMAX[24] Satus: 1 Power on WLAN MIH_Get_Info.confirm linK_Detected_Indication MIH_Get_Info.request [InfoQuerytype: TLV Infoqueryparameters: TYPE_IE_OPERATOR_ID TYPE_IE_Roaming Partner LinkType: WLAN] MIH_Get_Info_Request_Frame MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: OPERATOR_ID=XYZ Roaming Partner:=No] MIH_Get_Info.confirm Local MIHF Local MIHF User Remote MIHF User Remote MIHF MIH_Event_Indication MIH_Get_Info_Response_Frame MIH_Get_info_Request MIH_Get_Info_Request_Frame [InfoQuerytype: TLV Infoqueryparameters: TYPE_IE_OPERATOR_ID TYPE_IE_Roaming _Partner LinkType: WiMAX] Power on WiMAX linK_Detected_IndicationMIH_Event_Indication MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: OPERATOR_ID=DEF Roaming Partner= Yes] MIH_Get_Info.confirm Figure 2 : Proactive Handover Message Flows using IS

10. [InfoQuerytype: TLV Infoqueryparameters: OPERATOR_ID:DEF TYPE_IE_COST TYPE_IE_QoS LinkType: WiMAX] Mobile Assisted handover MIH_Get_info_Request MIH_Get_Info_Request_Frame MIH_Get_Info.Indication MIH_Get_Info.Response [InfoQuerytype: TLV MIH_report: OPERATOR_ID=DEF Cost=$$/hour QOS=Premium MIH_Get_Info.confirm MIH_Handover_Initiate _Indication MIH_Handover_Initiate _Request CurrentLinkType = UMTS[23] HandoverAck = 1 (Initiate Handover) PreferredLinkType = WIMAX PreferredPoA = BSID MIH_Handover_Prepare (?) MIH_Link_Detected_Frame MIH_Link_Detected_Indication MIH_Handover_Initiate_Request_Frame [LinkType = WiMAX POA ID = Base Station ID Network Identifier= DEF] Execute Handover {Network Controlled] as shown in Figure 2 Contd. Figure 2 : Proactive Handover Message Flows using IS Local MIHF Local MIHF User Remote MIHF User Remote MIHF WMAX MIH_Handover_Prepare_confirm