Unfortunately, there are still many problems within 3G/WLAN interworking, such as authentication efficiency, billing mechanism, non-repudiation service and user identity privacy etc.

• 然而，现今3G及WLAN的整合仍存在著许多问题，例如：认证机制的安全性和效率问题、计费机制、不可否认性服务、 使用者匿名性的保护以及提供连续性的服务等；