1. WiMAX_NWG_Stage2 & Stage3

1. 1. WiMAX_NWG_Stage2 & Stage3

2. WiMAX Forum The WiMAX Forum is a nonprofit organization formed in 2001 to enhance the compatibility and interoperability of equipment based on the IEEE 802.16 family of standards WiMAX Forum_Network Working Group (NWG) define Stage 1: use case scenarios and service requirements and defined along with Service Provider Working Group Stage 2: Architecture Tenets, Reference Model and Reference Points Stage 3: Detailed Protocols and Procedures

3. WiMAX Working Group ‧Application Working Group (AWG) ‧Certification Working Group (CWG) ‧Evolutionary Technical Working Group (ETWG) ‧Global Roaming Working Group (GRWG) ‧Marketing Working Group (MWG)

4. WiMAX Working Group ‧Network Working Group (NWG) ‧Regulatory Working Group (RWG) ‧Service Provider Working Group (SPWG) ‧Technical Working Group (TWG)

5. Relationship between the scopes of WiMAX NWG and 802.16 From IEEE 802.16 to WiMAX NWG build an interoperable broadband wireless network. Interoperable networks involve end-to-end service such as IP connectivity and session management, security, QoS, and mobility.

6. WiMAX Network Reference Model(1/2)

7. Decomposed ASN into BS and ASN GW entities

8. Entities of the WiMAX Network Reference Model (1/2) ASN: Access Serving Network Logical representation of the functions of a NAP, e.g. 802.16 interface network entry and handover Radio Resource Management & Admission ctrl. L2 Session/mobility management QoS and Policy Enforcement Foreign Agent (FA) Forwarding to selected CSN

9. Entities of the WiMAX Network Reference Model (2/2) CSN: Connectivity Serving Network Logical representation of the functions of a NSP, e.g. Connectivity to the Internet, ASPs Authentication, authorization and accounting IP address management L3 Mobility and roaming between ASNs Policy & QoS management based on a SLA

10. Network Reference point (1/2) R1: Reference point between MS and BS: implements IEEE 802.16e-2005. R2: Reference point between MS and ASN-GW or CSN: logical interface used for authentication, authorization, IP host configuration and mobility management. R3: Reference point between ASN and CSN: supports AAA, policy enforcement, and mobility –management capabilities. Implements tunnel between ASN and CSN. R4: Reference point between ASN and ASN: used for MS mobility across ASNs.

11. Reference point (2/2) R5: Reference point between CSN and CSN: used for internetworking between home and visited network. R6: Reference point between BS and ASN: implements intra-ASN tunnels and used for control plane signaling. R7: Reference point between data and control plane in ASN-GW: used for coordination between data and control plane in ASN-GW. R8: Reference point between BS and BS: used for fast and seamless handover.

12. WiMAX Network Reference Model(2/2)

13. ASN Network & GW

14. ASN-GW Reference model

15. Internetworking with 3GPP Scope WiMAX-3GPP Interworking refers to the integration of a WiMAX Access Network to an existing 3GPP core network.

16. 802.16e network entry In a WiMAX network, a full network entry includes four steps: a. Network Discovery and Selection b. Access Authentication c. Connection Setup d. Data Transfer

17. 802.16 TDD Frame Structure

18. Network entry • A WiMAX subscriber station has to complete the network entry process , in order to communicate on the network. • Steps: • Scan for DL channel and establish synchronization with the BS • Obtain transmit parameters (form UCD message) • Perform initial ranging • Negotiate basic capabilities • Authorize MS and perform key exchange • Establish IP connectivity • Establish time of day • Transfer operational parameters optional • Set up connections

19. a)Downlink Channel Synchronization: • When an SS wants to communicate on a WiMAX network, it first scans for available channels in the defined frequency list. On finding a DL channel, it tries to synchronize at the PHY level using the periodic frame preamble. Information on modulation and other DL and UL parameters is obtained by observing the DL Channel Descriptor (DCD) and the UL channel descriptor (UCD) of the DL channel.

20. Ranging(1/2) • b) Initial Ranging: • An SS starts an Initial ranging process by sending a ranging request MAC message using the minimum transmission power. If no response is received from the BS, the SS resends the message on a subsequent frame using a higher transmission power. The response either indicates power and timing corrections that the SS must make or indicates success. • Purpose: • The process by which the SS and BS maintain the quality of RF communication link between them.

21. Ranging(2/2) • Periodic ranging • Allows SS to adjust transmission parameters and maintain uplink communication with the BS.

22. c) Exchanging Capabilities: • After successful completion of the initial ranging step, the SS sends capability request message indicating the supported modulation level, coding scheme and rates and duplexing methods.

23. d) Authentication: • After capability negotiation, the BS authenticates the SS, determines the ciphering algorithm to be used, and sends an authentication response to the SS. • e) Registration: • After authentication, the SS sends a registration request message to the BS and the BS sends a registration response.

24. f) IP Connectivity: • After registration, the SS gets the IP address via DHCP. The SS also downloads other operational parameters using TFTP. • g) Connection Creation: • After completing the IP connectivity step, transport connections are created. For preprovisioned service flows, the BS sends a dynamic service flow addition request message to the SS and SS confirms the creation of connection. For non-preprovisioned service flows, connection creation is initiated by the SS by sending a dynamic service flow addition request message to the BS. The BS responds with the confirmation.

26. Network Discovery and Selection NAP discovery NSP discovery NSP Enumeration and selection ASN attachment based on NSP Selection

27. NSP Discovery

28. ASN Attachment based on NSP Selection

29. Connection setup • The ASN setup • Access Authentication • Binding of MS flow to intra-ASN DATA PATH • MIP req / resp • PMIP4 / CMIP4 / CMIP6 • MIP tunnel

30. Connection setup procedure( DHCP proxy )

31. Connection setup procedure( CMIPv4 )

32. Connection Setup Procedure (CMIP6 )

33. Mobility management The WiMAX mobility solution consists of two mobility levels Intra-ASN mobility ASN Anchored Mobility inter-ASN mobility ASN-anchor (based on profile A & C) CSN Anchored Mobility

34. ASN Anchored Mobility Management(1/4) • ASN Anchored Mobility Management is defined as mobility of an MS not involving a CoA update (MIP re-registration)

35. ASN anchor Mobility (2/4)

36. ASN anchored mobility (3/4)

37. CSN Anchor mobility( R3-mobility ) Re-anchoring of the current FA to a new FA and the consequent binding updates to update the upstream and downstream data forwarding paths.

38. Authentication, Authorization and Accounting The WiMAX AAA framework is based on IETF specifications. The term AAA is used to refer to the AAA protocols, Radius or Diameter. The AAA framework provides the following services to WiMAX: Authentication Services These include MS, user, or combined MS and user authentication. Authorization Services These include the delivery of information to configure the session for access, mobility, QoS and other applications. Accounting Services These include the delivery of information for the purpose of billing (both prepaid and post paid billing) and information that can be used to audit session activity by both the home NSP and visited NSP.

39. Accounting Architecture

40. QOS IEEE 802.16 MAC is connection oriented. Each connection, upon establishment, subscribes to one of the scheduled services Resource allocation, admission, and scheduling is controlled the base station

41. QoS Functional Elements • Service Flow Management (SFM) • responsible for the creation, admission, activation, modification and deletion of 802.16 service flows. • Service Flow Authorization (SFA) • Evaluate any service request against user QoS profile. • AF: Application Function • e.g., SIP Proxy • PF: Policy Function • Maintained information includes H-NSP's general policy rules • LPF: Local Policy Function • enforce admission control based on available resources

42. Handoff Function The following types of handovers are supported by the handoff function. Mobile initiated handovers at a given serving Base-Station. Network initiated handovers. FBSS and MDHO (possibility to support MDHO SHOULD be further discussed) The Handoff Function can be further classified by its roles in handover operation as follows Serving HO Function Relaying HO Function Target HO Function

43. IEEE 802.16e Handoff Process The stages of Handoff Process • Handoff decision stage • Handoff planning stage • Handoff execution stage

44. HO Function Network Transaction

45. Reference Wimax forum WiMAX End-to-End Network Systems Architecture (Stage 3: Detailed Protocols and Procedures) Wimax forum WiMAX End-to-End Network Systems Architecture (Stage 2)