The problem Statement of Broadband Wireless Access Technologies

Richard, Tom Taylor, Eva Chang, Tina Tsou

Overview

Wired Access

NAS

AAAAAA Broadband Wireless Access technologies are widely deployed.

WiFi/WiMAX 2G/3G/LTE

When some wired carriers extend their network with wireless access technologies, they prefer to reuse NAS architecture.

Chinese Carriers have deployed hundreds of thousands of WLAN APs.

Special attention to QOS and service control is also required by Broadband Wireless Access Network.

A tighter coordination between NAS and Wireless AN is necessary.

Wireless Access

The Problem Statement

Roaming

Need to track subscriber’s location changes

Need to avoid subscriber re-authentication to improve quality of experience by relaying roaming status to NAS.

Example: WiFi network• NAS authentication method is Portal• UE moves from one AN to another• UE's IP address is usually changes• UE has to be re-authenticated at the

NAS although the second AN understands its roaming status.

If second AN reports roaming information to NAS, re-authentication can be avoided

Subscriber’s roaming experience will be improved.

Wireless AN

NAS

AAAAAA

WTP

Wireless AN

WTP WTP WTP

Roaming scenario

Wireless access protection (Such as WiFi WPA, WPA2)

NAS will inevitably help to negotiate key materials used for air protection, and it should deliver the intermediate key material (called PMK in WiFi) to wireless AN .

• really a HOKEY problem, not ANCP

Specific identification for wireless subscriber

For DSL access technology, a PVC represents a subscriber. But for wireless access technology, many subscribers can access with the same radio. Hence many subscribers may use the same VLAN. So when the subscriber’s information is exchanged , subscriber-specific detailed information needs to be included.

Radio Resource Control

Radio spectrum is a precious and limited resource. Communication between the wireless AN and NAS makes it possible to allocate radio resources more efficiently between different wireless subscribers. For example, by policy, Wireless AN may kick off the inactive subscribers.

The Problem Statement (cont)

Discussion of Candidate Solution

Reuse the general framework and protocol of ANCP

Extend and define wireless specific message types (for discussion)

New wireless capabilities need to be defined for establishment of adjacency relationshipNew wireless subscriber identification needs to be definedNew message type needs to be defined for identifying invalid or unauthenticated user to AN for better radio resource controlNew message type need to be defined for AN to update NAS with roaming user information for better roaming experience