We develop algorithms to provide Quality of Service (QoS) support for prioritized, bandwidth-adaptive and fair media streaming using a multimedia server cluster. We formulate the underlying related problems of prioritized client admission control, redirection to appropriate streaming server, adaptive client quality control, and server load-balancing as one combined optimization. This optimization corresponds to solving a Multiple Choice Multiple Knapsack Problem, which is in general NP hard. By partitioning this optimization into two separate related optimizations we can design several low- complexity algorithms to provide exact and approximate solutions. We select a log-linear utility function that maintains differentiability and captures the video quality to measure the derived client and system benefit. We provide bounds on the performance of these algorithms, and examine the system time evolution in terms of the number of clients supported and QoS provided to each client, over realistic simulation scenarios.

Making high-bandwidth Internet access pervasively available to a large worldwide audience is a difficult challenge, especially in many developing regions. As we wait for the uncertain takeoff of technologies that promise to improve the situation, we propose to explore an approach that is potentially more easily realizable: the use of digital storage media transported by the postal system as a general digital communication mechanism. We shall call such a system a Postmanet . Compared to more conventional wide-area connectivity options, the Postmanet has several important advantages, including wide global reach, great bandwidth potential, low cost, and ease of incremental adoption. While the idea of sending digital content via the postal system is not a new one, none of the existing attempts have turned the postal system into a generic and transparent communication channel that not only can cater to a wide array of applications, but also effectively manage the many idiosyncrasies associated with using the postal system. In the proposed Postmanet, we see two recurring themes at many different levels of the system. One is the simultaneous exploitation of the Internet and the postal system so we can combine their latency and bandwidth advantages. The other is the exploitation of the abundant capacity and bandwidth of the Postmanet to improve its latency, cost, and reliability.

The phenomenon that rural residents and people with low incomes lag behind in Internet access is known as the "digital divide." This problem is particularly acute in developing countries, where most of the world's population lives. Bridging this digital divide, especially by attempting to increase the accessibility of broadband connectivity, can be challenging. The improvement of wide-area connectivity is constrained by factors such as how quickly we can dig ditches to bury fibers in the ground; and the cost of furnishing "last-mile" wiring can be prohibitively high.In this paper, we explore the use of digital storage media transported by the postal system as a general digital communication mechanism. While some companies have used the postal system to deliver software and movies, none of them has turned the postal system into a truly generic digital communication medium supporting a wide variety of applications. We call such a generic system a Postmanet. Compared to traditional wide-area connectivity options, the Postmanet has several important advantages, including wide global reach, great bandwidth potential and low cost.Manually preparing mobile storage devices for shipment may appear deceptively simple, but with many applications, communicating parties and messages, manual management becomes infeasible, and systems support at several levels becomes necessary. We explore the simultaneous exploitation of the Internet and the Postmanet, so we can combine their latency and bandwidth advantages to enable sophisticated bandwidth-intensive applications.