Mobile converged networks [Guest Editorial]

Driven by the ever increasing popularity and demand of multimedia contents, wireless traffic is expected to increase 1000 times in the next 10 years. A looming problem is how to identify a frequency band, from the already scarce spectrum resources, to fulfill this requirement. A feasible cost-efficient solution is to integrate several existing network resources, which have been allocated for different services, to form a single mobile converged network. These existing networks operate independently on different frequency bands, including the cellular network, video broadcast, wireless sensor network (WSN), and wireless local area network (WLAN). Each of them, alone, has its own historic justification, but suffers certain drawbacks in one way or another. For instance, the cellular network was originally designed to offer voice service, lacking an efficient means of broadcasting multimedia contents. Clearly, integrating these heterogeneous networks will constitute a much more powerful unified framework able to fully exploit the capability and radio resources of all the individual networks, provide a platform for the Internet of Things, and enable users to enjoy a uniform service everywhere by using a software-defined radio device. The benefits of converged networks are promising; however, the road to success is filled with challenges. The networks integration necessitates a harmonious interaction among heterogeneous networks at different levels, thus requiring a careful design of network architecture, coordination protocols, and resource allocation algorithms for efficient operation of the converged network.