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Network Discovery and Selection/Re-selection OUTLINE 2 Network Model Use-case Scenario Solution IP Addressing Network Model ASN: Access Service Network – NAP: Network Access Provider – 3 A ASN contains BSs and ASN-GWs. A NAP contains one or more ASNs. NSP: Network Service Provider Network Model Visited NSP R2 Home NSP R2 R3 R1 SS/ MSS R5 ASN CSN CSN SS R4, Another ASN NAP 4 ASP Network OR Internet ASP Network OR Internet Deployment case NAP Sharing – 5 More than one NSPs shares the same NAP NAP+NSP Use-case Scenario 1.First-time use 2.Initial network entry 3.Network Re-entry – 4.MSS transitions across NAP coverage areas – 6 The same as handoff within the same WiMAX NAP Due to user movement or confounding factor, MSS elects to transition another NAP Solution In a WiMAX network, a full network discovery and selection procedure includes four steps: 1.WiMAX NAP Discovery 2.NSP Access Discovery 3.NSP Enummeration and Selection 4.ASN Attachment based on NSP selection 7 Two WiMAX network selection modes are defined, automatic and manual. Solution (1) WiMAX NAP Discovery – – – An SS/MS detects available NAPs by scanning and decoding DL-MAP of ASN on detected channel. The most significant 24-bit value of “operator ID” within the “BS ID” parameter in the DL-MAP message is the NAP Identifier. In NAP+NSP deployment case, NAP identifier shall be identical with NSP identifier. NAP discovery is based on the procedures defined in IEEE Std 802.16-2004 [x1] 8 Solution (2) NSP Access Discovery – – – 9 The SS/MS shall sequentially perform association with each NAP for the purpose of discovering the supported NSPs The ASN transmits the NSP ID list message no less than once every five seconds. For SS/MS with configuration information that includes a list of NAP + NSP unitary mappings, WiMAX NAP Discovery of the NAP Identifier is sufficient to provide NAP and NSP. Solution (3) NSP Enumeration and Selection – – – 10 Manaul or Automatic mode If displayed, NSPs from the list of available NSPs shall be presented in the following order: a) Home NSP b) NSPs in the "User Controlled NSP Identifier list" data file in the SS/MS c) NSPs in the "Operator Controlled NSP Identifier list" data file d) Any other NSP in random order The signal quality shall not be used as a parameter for NSP Selection Solution (4) ASN Attachment based on NSP selection An SS/MS indicates its NSP selection by attaching to an ASN associated with the selected NSP, and by providing its identity and home NSP domain in form of NAI. – The ASN uses the NAI to determine the next AAA hop to where the MS’s AAA packets should be routed. NAI (Network Access Identifier) Example: – MS_1 uses a normal/root NAI (i.e., user-name@NSP_1.com) – MS_2 needs to construct a decorated NAI (e.g., NSP_4!user-name @NSP_1.com) ASN Sharing – – [RFC4282] ASN of NAP_1 MSS_1 of NSP_1 11 MSS_2 of NSP_4 CSN of NSP_1 CSN of NSP_2 CSN of NSP_3 CSN of NSP_4 Solution (5) NSP Access Discovery(2) and NSP Enumeration(3) and Selection may well occur concurrent to WiMAX NAP Discovery(1) . There is no requirement that an SS/MS discover all NAPs and NSPs. – 12 An SS/MS may stop the discovery process on discovery of a NAP and NSP meeting the SS/MS NSP Enumeration and Selection criteria and proceed to ASN Attachment. Configuration Information in SS/MSS User/Operator controlled NAP Identifier list – User/Operator controlled NSP Identifier list – The lists are used to select a NSP. NAP/NSP mapping list – Information useful in NAP Discovery including channel, center frequency, and PHY profile Network deployment mode – 13 Indicating whether the list of supported NSPs for a NAP is changed Physical information: – Indicating the supported NSPs per NAP NSP Count – Determining priority order of performing NSP Access Discovery procedure among if there are more than one available NAP. Indicating the Network deployment mode of each NAP, i.e. NAP+NSP mode or NAP sharing mode. IP Addressing The functional entity residing in ASN-GW is a DHCP relay. Functional Decomposition for PoA from Visited NSP Functional Decomposition for PoA from Home NSP 14 IP configuration setup The functional entity residing in ASN-GW is a DHCP relay. Access authentication: – the network assigning the PoA address is determined. MSS BS Access Authentication DHCP Proxy Relay DHCP Server H-AAA Access Authentication (DHCP Server @) 1) Access Authentication 2) DHCP Discove r 3) DHCP Discove r (giaddr) 4) DHCP Offer (MSS IP@) 5) DHCP offer (MSS IP@ ) 6) DHCP Reques t 7) DHCP Reques t 8) DHCP Ack 15 DHCP Gating 9) DHCP Ack Through DHCP or AAA at Authorization time