Recent advances in communications technologies have witnessed a growing and evolving multimedia content delivery market based on information gathering, manipulation, and dissemination. It is a fact that personal communications, computing, broadcasting, entertainment, etc. have turned into streams of multimedia content, and the various communication and network technologies have become the means to carry that content to a wide variety of terminals. Unlike traditional communication systems, a fundamental challenge for present and future communication systems is the ability to transport multimedia content over a variety of networks in an energy efficient manner at different channel conditions and bandwidth capacities with various requirements of QoS. There are many issues that need to be addressed such as signal processing, collaborations, power management, flexible delivery, specialization of new content, dynamic access, telecommunications, networking, etc., because of the multidisciplinary nature of the applications in advanced multimedia communications.
The goal of this issue is to bring together the state-of-the-art research contribution that describes original and unpublished work addressing the new emerging techniques on multimedia communications. Especially, we solicit research papers on addressing challenging issues existing for enabling mobile multimedia communications over heterogeneous infrastructure for realizing next generation networking and computing. For example, ubiquitous multimedia is a requirement in next generation networks, such as multimedia adaption in wireless network; multimedia services in ubiquitous circumstance; and improving distributed multimedia communication through location awareness, action awareness, user awareness, etc. On the other hand, because of the limited computational power, memory, and battery energy in wireless and portable terminals, power-efficient design also plays an important role in next-generation mobile multimedia applications.
We have received a large number of papers from both academia and industries that covered a variety of interesting topics related to multimedia communications. Two rounds of careful review by the guest editors and experts in the field led to nine papers for inclusion in this issue.
The first paper 'Tournament-based congestion control protocol for multimedia streaming in ubiquitous sensor networks' by Lee et al., addresses the issue of congestion and latency, which have impact on energy efficiency, memory size, buffer size, and throughput in the ubiquitous sensor network. The authors propose a new method, called TCCP (tournament-based congestion control protocol), where the winner is the stream with the highest importance level in the competition of ubiquitous sensor networks. In general, there are a lot of congestion and delay in the continuous streaming of multimedia streams with lower importance level. The proposed method consists of three parts: tournament decision, best-fit control strategy, and service differentiation. The final winner in the tournament controls congestion effectively, minimizes packet loss because of congestion, decreases energy consumption, and improves QoS. The simulation result shows that the proposed