Interworking – WLAN Control

1. Interworking – WLAN Control Cheng Hong & Tan Pek Yew Panasonic (WNG-SC) Date : 10th November 2003 Cheng Hong, Tan Pek-Yew, Panasonic

2. Why control in WLAN? • WLAN interworking is a reality in today’s commercial deployments • For a subscribed service, the users are paying for access, hence they would expect certain guarantees. It’s no longer a free trial. • E.g. 3GPP, 3GPP2, etc are developing solutions; hotspot access using same account from the operator is available Wireless Broadband Alliance (www.wirelessbroadbandalliance.com ) • Services available through the interworking requires control of the bearer and provision of end-to-end QoS • E.g. VoIP service for Wi-Fi phone, 3G IMS service over WLAN • Controls in the WLAN are required to support consistent user experience in large scale deployments • User traffic should be treated according to the user subscriptions • User service authorization and admission control requires the WLAN to enforce the result, e.g. allow/block access etc Cheng Hong, Tan Pek-Yew, Panasonic

3. Policy control and Mobility • Policy control mechanisms in the WLAN are necessary for linking local QoS to the end-to-end QoS for interworking • For instance, current IEEE 802.11e controls only have local significance. Utilizing it for end-to-end QoS requires standardization work. • IETF CAPWAP structure makes it possible for more sophisticated control through Access Router; • For a public access WLAN, admission control and user level authorization is important for service level guarantees (terminal behavior regulation) • Service continuation with end-to-end QoS needs Layer 2 support in mobility • Service continuity and seamless mobility require layer 2 support, e.g. movement detection, fast handoff etc • Similar investigation is carried out in the IETF DNA for the layer 2 hint for upper layer mobility support Cheng Hong, Tan Pek-Yew, Panasonic

4. Example: Requirements from 3GPP on traffic enforcement • Traffic from the WLAN UE should be controlled and metered. • Reasons: Inter-operator accounting; user would pay for the traffic accordingly • To access 3G services, UE’s traffic must pass through the 3GPP network. • Security reason; operator accounting reasons; policy control, QoS guarantee. • WLAN needs to support other non-interworking UEs, and UEs not accessing 3G services • i.e. there could be direct data path to external networks or the Internet. Cheng Hong, Tan Pek-Yew, Panasonic

5. Impacts on the WLAN (traffic enforcement) • WLAN needs to differentiate users • Users should be bound to their 3G network subscriptions. • Users roaming from different 3G networks could be treated differently (due to operator roaming agreements). • Necessary information could be obtained through authentication and authorization. • WLAN needs to differentiate UE traffic • Only traffic for accessing 3G services would be routed through the 3GPP network • Traffic destined for the Internet would be sent to Internet directly • WLAN needs to prevent source address spoofing • Traffic should be bound to the correct UE. Cheng Hong, Tan Pek-Yew, Panasonic

6. Work for the WIG • Standardize the mechanism for traffic enforcement at the WLAN AN • E.g. VLAN support , how the QoS is provided etc. • Standardize the interface and relevant information elements for the traffic enforcement control • May be integrated with other functions, e.g. tunneling, policy/QoS control • Study the interaction of this interface with other interfaces • E.g. the authentication and compulsory tunnel, RADIUS extension support, CAPWAP structure, etc Cheng Hong, Tan Pek-Yew, Panasonic