Signaling for multimedia conferencing in 4G: the case of integrated 3G/MANETs

Fourth-generation wireless systems are composed of coexisting and cooperating legacy and new networks. Mobile ad hoc networks are examples of new networks. They have several attractive characteristics and are gaining more and more momentum. Their integration with legacy third-generation networks is now being contemplated. Multimedia conferencing is the basis of a wealth of applications, including video conferences, multiparty games, and distance learning. Signaling is the central nerve of multimedia conferencing. It establishes, modifies, and tears down multimedia conferencing applications. This article is devoted to the signaling aspects of multimedia conferencing in 4G and focuses on the specific case of integrated 3G/MANETs. It reviews the standard 3G architecture and the emerging architectures for MANETs. This review shows that none of them is suitable for integrated 3G/MANETs. We propose a new architecture based on application-level clusters and conference gateways. We have implemented a prototype using the session initiation protocol (SIP) technology.

Introduction

Standardization of fourth-generation (4G) wireless systems has not yet begun. However, there is a broad consensus around the vision of the Wireless World Research Forum (WWRF) [1]. The WWRF foresees 4G wireless systems as being made up of both legacy and new networks coexisting and cooperating. Third-generation networks (3G) are the prime legacy networks, as they continue to be deployed. Mobile ad hoc networks (MANETs) are emerging as new networks, and they are gaining more and more momentum. MANETs can be defined as transient networks formed dynamically by a collection of arbitrarily located wireless mobile nodes without relying on any existing network infrastructure or centralized administration [2]. They are flexible and easy to deploy, which makes their coexistence and cooperation with 3G networks an interesting topic for investigation. However, thus far research has been focused on lower-layer integration and related issues.