Enhancing Patching Performance Through Double Patching

Patching is an efficient bandwidth-sharing technique for video-on-demand systems. Its performance, however, has limitation: as the time distance to the last regular multicast enlarges, the patching cost for new requests increases and eventually, a new regular multicast must be scheduled to balance the cost. In this paper, we address this problem by proposing a new technique called Double Patching. Our research is based on the observation that a patching stream can be shared by the video requests arriving in the next wp time units if it delivers an additional 2 · wp time units of video data. With these additional data, the patching cost for these requests can be significantly reduced. Our performance study shows that the new technique can dramatically improve, in many workloads double, the performance of the original Patching. While the performance gain is significant, the new technique inherits the same simplicity from the original Patching. In particular, it does not impose any additional requirement on client download bandwidth - the same as the original Patching, the new scheme allows a client to receive data from no more than two video streams at any one time

SON : a framework for Internet TV broadcast with incentive forwarding

In this thesis, we propose a framework, called Subscription Overlay Network (SON), for real-time Internet TV broadcast, where a subscriber can choose to watch at any time. This framework allows the source server to incrementally build a topology graph that contains the network connections not only from the server to each subscriber, but also among the subscribers themselves. With such topology graph in place, we consider efficient overlay multicast for scalable SON services. We first show that idling nodes, which do not receive video data for their own playback, can actually be used for data forwarding to significantly reduce the cost of overlay multicast. In light of this observation, we then propose a novel overlay multicast technique, which distinguishes itself from existing schemes in three aspects. First, the proposed technique is centered on the topology graph and can take advantage of the actual network connections among the subscribing nodes. Second, the new scheme is able to find and incorporate appropriate idling nodes in multicast to reduce network traffic. Third, with our approach, a node can be used in multiple multicast trees for data forwarding to improve the overall system performance. We evaluate the performance of the proposed technique through simulation. Our extensive studies show that the proposed framework has the potential to enable the Internet, a vehicle up to date mainly for transferring text and image data, for large-scale and cost-effective TV broadcast

Tune to Lambda Patching

describes Patching as a technique for reducing server load in a true video-on-demand (TVoD) system. It is a scheme for multicast video transmissions, which outperforms techniques such as Batching in response time and Piggybacking in bandwidth savings for titles of medium popularity, and probably in user satisfaction as well. It achieves TVoD performance by buffering part of the requested video in the receiving endsystem. In a further study, the authors give analytical and simulation details on optimized patching windows under the assumptions of the Grace and Greedy patching techniques. In our view, this does not exploit fully the calculation that was performed in that study. We state that temporal distance between two multicast streams for one movie should not be determined by a client policy or simulation. Rather, it can be calculated by the server on a per video basis, since the server is aware of the average request interarrival time for each video. Since we model the request arrivals as a Poisson process, which is defined by a single variable that is historically called λ, we call this variation “λ Patching”. Furthermore, we present an optimization option “Multistream Patching ” that reduces the server load further. We accept that some near video-on-demand-like traffic is generated with additional patch streams, and achieve additional gains in server load