Ioannis Kriaras

Wireless VoIP: Opportunities and Challenges

Next generation wireless networks are going to use IP capable mobile terminals and support both voice/multimedia and data services. VoIP is a promising technology allowing a converged core network for all services, and provides a service platform for easier and quicker service creation. Application of VoIP in wireless networks, however, is not so straightforward as people may expect. Among other issues, mobility support is perhaps the most challenging one. The different levels of mobility support (terminal, personal and service mobility) highlight the gap between the existing VoIP framework, which is so far focusing on fixed networks, and the requirements in a wireless environment. After analyzing the existing solutions/proposals for this problem, a framework is proposed in which the mobility-related services are decomposed into several levels so that mobility support is made available to many applications. This layered approach would help to lead to a mobility enabled wireless IP infrastructure in which voice service is just an application.

RSSP: RSVP session set-up protocol for RSVP-incapable multimedia applications

RSVP is the QoS signalling protocol used with Integrated Service Framework for QoS provisioning in IP networks. The existing RSVP mechanism requires that an RSVP daemon be embedded with the applications so as to initiate RSVP sessions. This requirement has been envisaged to be a major limitation over the use of RSVP and the associated QoS control mechanisms for those applications or platforms which are either RSVP-incapable or impossible to be modified to introduce a built-in RSVP capability. This paper introduces a mechanism, RSVP Session Set-up Protocol, which overcomes the limitations of existing RSVP implementations by initiating RSVP sessions for RSVP-incapable applications running on different platforms. The proposed mechanism features application and platform independence and eliminates the need for built-in RSVP processing capability for those applications or terminals of short battery life and limited processing power. Moreover it facilitates dynamic QoS provision for wireless mobile devices during hand-off control.