Guest Editorial the First Paper of the Special Issue Is Entitled ''real-time Multimedia Processing in Video Sensor Networks (vsn)'', and Authored the Second Paper ''multiple Description Video Coding Using Coefficients Ordering and Interpola- Tion'', By

The successful development of video-based services and applications in mobile environments requires adopting integrative approaches that jointly address video signal processing and networking issues. Multimedia data characteristics, coding standards and functionalities, as well as network protocols performance and channel behavior are some of the key aspects that need to be carefully examined in the design of new mobile communication applications that will enable video telephony, interactive gaming, digital television, or immersive communications in virtual environments, for example. Recent advances in video processing and coding (e.g. H.264 and Scalable Video Coding), jointly with novel networking protocols and technologies such as IEEE 802.11 (infrastructured, mesh, and sensor networks), 802.15, 802.16, UWB, DVB-H, Bluetooth, Mobile IP and its variants, lay the ground for the development of new and efficient mobile video services. This Special Issue reports the results of recent advances in the field by presenting a collection of articles that address problems related to coding, signal processing, transmission, protocols, for robust and efficient video delivery over wireless and mobile communication channels. Some of these papers are extensions of papers that were presented at the Mobile Multimedia Communications Conference (MobiMedia 2006) that was held in Alghero, Italy. The first paper of the special issue is entitled ‘‘Real-Time Multimedia Processing in Video Sensor Networks (VSN)’’, and authored by Yaoyao Gu, Yuan Tian, and Eylem Ekici. It investigates the problems of in-network processing, task mapping and scheduling in VSN, and presents an application-independent solution in multi-hop VSNs. The proposed algorithm provides real-time guarantees to process video feeds and schedules communication and computation tasks of an application with minimum energy consumption, subject to delay constraints. It is based on the high-level application