In traditional near-VOD (NVOD), the number of streams required is high if the user delay goal is low (say, 2 minutes). In this paper, we study the use of client buffering to reduce such bandwidth requirement. We first study a scheme based on streaming approach termed "join-and-stream" (JAS), which broadcasts a movie in a staggered manner and uses short unicast streams to recover the time difference between the broadcast point and the arrival time. We show that such a technique is effective for movies with intermediate arrival rate. We then propose a broadcasting scheme for popular movies termed "stream-bundling." The scheme groups (i.e., "bundles") the server streams into channels of incrementally increasing bandwidth. Such high-speed bundled channels are used to deliver the beginning portion of the videos to the clients, so that the clients can merge with an ongoing broadcast stream quickly. By comparing with other previously proposed broadcasting schemes (such as Pyramid Broadcasting, Skyscraper Broadcasting and Harmonic Broadcasting), stream-bundling is shown to achieve similar level of performance with much lower complexity (without many channels to manage and to hop). Using our two schemes, the bandwidth requirement of a system can be reduced significantly (by more than 50% in our examples) as compared with the traditional NVOD, with the cost of only a little client buffering (20% of the movie length).

Abstract-In designing a video broadcasting system, the delay preference of a user is traditionally regarded as unknown. In fact, such preference can be known upon user's arrival by employing some techniques such as i) delay-dependent charging, where users are offered different levels of pay-per-view (PPV) depending on the maximum delay they are willing to tolerate; or ii) reservation, where a user specifies the exact play-time of a movie in advance, and he/she is charged according to the length of the reservation period. We explore, for the first time, the impact of such delay knowledge on request scheduling and system cost in terms of user loss and stream requirement. For delay-dependent charging, we propose "Delay-Aware Broadcasting" (DAB) and its variant based on reservation (DAB-r), where allocation of server streams is driven by the delay tolerance of a user. DAB-r offers differentiated grade of services according to user PPVs (and thereof classes). As compared with a system where user delay preference is not known, our schemes achieve substantially lower user loss rate, higher revenue, and better fairness. Regarding reservation system, we consider a scheme where clients can pre-buffer video data. Unicast streams are used to merge requests back to the on-going broadcast streams. We show that a reservation system achieves substantially lower stream requirement as compared to an on-demand system based on "patching."Index Terms-Delay-aware broadcasting, delay preference, reservation scheme, stream requirement, video broadcasting.

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Exsanguinating neck injury is a rare presentation to the emergency department. However, when such a scenario occurs, emergency physicians should be able to readily employ the various methods available to control the exsanguination. Furthermore, the application of inotrope or vasopressor in a hypotensive traumatic patient despite aggressive fluid/ blood product resuscitation is explored.