The present invention provides a method of handing off a mobile unit that supports multiple quality-of-service (QoS) application layer clients that operate according to multiple wireless access technologies in a packet-switched communication system. The method includes receiving information indicating a request to hand off the mobile unit from a first access network that operates according to a first wireless access technology to a second access network that operates according to a second wireless access technology. The mobile unit established a first session according to the first wireless access technology at a first QoS level. The method also includes establishing, concurrently with the first session and in response to receiving the handoff request, a second session according to the second wireless access technology at the first QoS level. The method further includes communicating with the mobile unit at the first QoS level using the first and second sessions.