At the recent RAN2 meeting (May 20-24, 2013), the discussions focused mainly on access network selection and traffic steering in 3GPP-WLAN interworking scenarios. The proposed solutions addressed the following cases:
UE is within UTRAN/E-UTRAN coverage, is using 3GPP and goes into WLAN AP coverage
B. UE is within UTRAN/E-UTRAN and WLAN coverage, is using WLAN and goes out of WLAN AP coverage
C. UE is within the coverage area of both, UE using WLAN, all or a subset of the UE’s traffic should be routed via UTRAN/E-UTRAN instead
D. UE is within the coverage area of both, UE using UTRAN/E-UTRAN, all or a subset of the UE’s traffic should be routed via WLAN instead
E. UE using both accesses and should be connected to only one (WLAN or UTRAN/E-UTRAN) or some traffic should be moved to the other access
In broad terms, there are 3 solutions currently being discussed in RAN2:
Solution 1: 3GPP RAN provides UE with information that assists in network selection and traffic steering. This information may be combined with ANDSF rules and/or UE configuration to decide whether to connect to a WLAN, if one is available, and to steer one or more flows to the WiFi link.
Solution 2: 3GPP RAN provides the access network selection parameters, based on which the UE decides when to connect to a WLAN. These parameters may includes thresholds, priorities, rules etc.
Solution 3: UE reports available WLAN(s) based on measurements configured by 3GPP RAN and the decisions related to WLAN selection as well as traffic steering are taken by the network.
In the next post, I will discuss each of these solutions in more detail.