A System Architecture for Managing Mobile Streaming Media Service

A mobile streaming media content delivery network (MSM-CDN) overlay system provides a scalable method for delivering media streams to a large number of clients. With the availability of such a streaming infrastucture, it becomes possible to implement enhanced media services. For example, the wide range and variability of network conditions, as well as processing and display capabilities of these devices will effectively require media streams to be adapted in the network. Each streaming session needs to be tailored to these changing environments in a practical and scalable manner. Media transcoding services can be performed by the servers of the MSM-CDN overlay, providing this flexibility. Due to the computational and bandwidth requirements of real-time video transcoding, these services require management of the placement of these tasks on the most appropriate servers, to make best use of the distributed resources available within the network. In this paper, we address the media service assignment problem using the notion of service-location management (SLM). An effective load balancing system requires appropriate resource monitoring. We propose alternate SLM resource monitoring schemes. Using media transcoding as a representative service, we compare the performance of these schemes on an MSM-CDN testbed. We present our conclusions on which of these alternate implementations is both most reliable and most extensible to serve a large numbers of mobile client requests.