Network Discovery and Selection/Re-selection

2 OUTLINE Network Model Use-case Scenario Solution IP Addressing

3 Network Model ASN: Access Service Network – A ASN contains BSs and ASN-GWs. NAP: Network Access Provider – A NAP contains one or more ASNs. NSP: Network Service Provider

4 Network Model

5 Deployment case NAP Sharing – More than one NSPs shares the same NAP NAP+NSP

6 Use-case Scenario 1.First-time use 2.Initial network entry 3.Network Re-entry – The same as handoff within the same WiMAX NAP 4.MSS transitions across NAP coverage areas – Due to user movement or confounding factor, MSS elects to transition another NAP

7 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 Two WiMAX network selection modes are defined, automatic and manual.

8 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 [x1]

9 Solution (2) NSP Access Discovery – 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.

10 Solution (3) NSP Enumeration and Selection – 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

11 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., – MS_2 needs to construct a decorated NAI (e.g., – [RFC4282]

12 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. – 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.

13 Configuration Information in SS/MSS User/Operator controlled NAP Identifier list – Determining priority order of performing NSP Access Discovery procedure among if there are more than one available NAP. User/Operator controlled NSP Identifier list – The lists are used to select a NSP. NAP/NSP mapping list – Indicating the supported NSPs per NAP NSP Count – Indicating whether the list of supported NSPs for a NAP is changed Physical information: – Information useful in NAP Discovery including channel, center frequency, and PHY profile Network deployment mode – Indicating the Network deployment mode of each NAP, i.e. NAP+NSP mode or NAP sharing mode.

14 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

15 IP configuration setup The functional entity residing in ASN-GW is a DHCP relay. Access authentication: – the network assigning the PoA address is determined.