Recent years have witnessed an explosive growth in multimedia streaming applications over the Int... more Recent years have witnessed an explosive growth in multimedia streaming applications over the Internet. Notably, Content Delivery Networks (CDN) and Peer-to-Peer (P2P) networks have emerged as two effective paradigms for delivering multimedia contents over the Internet. One salient feature shared between these two networks is the inherent support for path diversity streaming where a receiver receives multiple streams simultaneously on different network paths as a result of having multiple senders. In this paper, we propose a network coding framework for efficient video streaming in CDNs and P2P networks in which, multiple servers/peers are employed to simultaneously stream a video to a single receiver. We show that network coding techniques can (a) eliminate the need for tight synchronization between the senders, (b) be integrated easily with TCP, and (c) reduce server's storage in CDN settings. Importantly, we propose the Hierarchical Network Coding (HNC) technique to be used with scalable video bit stream to combat bandwidth fluctuation on the Internet. Simulations demonstrate that under certain scenarios, our proposed network coding techniques can result in bandwidth saving up to 60% over the traditional schemes.
With the explosive growth of video applications over the Internet, many approaches have been prop... more With the explosive growth of video applications over the Internet, many approaches have been proposed to stream video effectively over packet switched, best-effort networks. Many use techniques from source and channel coding, or implement transport protocols, or modify system architectures in order to deal with delay, loss, and time-varying nature of the Internet. In our previous work , we proposed a framework with a receiver driven protocol to coordinate simultaneous video streaming from multiple senders to a single receiver in order to achieve higher throughput, and to increase tolerance to packet loss and delay due to network congestion. The receiver-driven protocol employs two algorithms: rate allocation and packet partition. The rate allocation algorithm determines the sending rate for each sender; the packet partition algorithm ensures no senders send the same packets, and at the same time, minimizes the probability of late packets. In this paper, we propose a novel rate allocation scheme to be used with Forward Error Correction (FEC) in order to minimize the probability of packet loss in bursty loss environments such as those caused by network congestion. Using both simulations and actual Internet experiments, we demonstrate the effectiveness of our rate allocation scheme in reducing packet loss, and hence, achieving higher visual quality for the streamed video.
In today's heterogeneous network environment, there is a growing demand for distrusted parties to... more In today's heterogeneous network environment, there is a growing demand for distrusted parties to jointly execute distributed algorithms on private data whose secrecy needed to be safeguarded. Protocols that support such kind of joint computation without complete sharing of information are called secure multiparty computation (SMC) protocols. Applying SMC protocols in image processing is a challenging problem. Most of the existing SMC protocols are implemented based on cryptographic primitives like oblivious transfer that are too computational intensive for pixel-based operations. In this paper, we develop two efficient SMC protocols for distributed linear image filtering between two parties, one party with the original image and the other with the image filter. The first protocol is based on a combination of rank reduction and random permutation. The second one uses random perturbation with the help of a non-colluding third party. Experimental results show that both of them execute significantly faster than oblivious-transfer based techniques.
In recent years, Content Delivery Networks (CDN) and Peerto-Peer (P2P) networks have emerged as t... more In recent years, Content Delivery Networks (CDN) and Peerto-Peer (P2P) networks have emerged as two effective paradigms for delivering multimedia contents over the Internet. An important feature in CDN and P2P networks is the data redundancy across multiple servers/peers which enables efficient media delivery. In this paper, we propose a network coding framework for efficient media streaming in either content delivery networks or P2P networks in which, multiple servers/peers are employed to simultaneously stream a video to a single receiver. Unlike previous multi-sender schemes, we show that network coding technique can (a) reduce the redundancy storage, (b) eliminate the need for tight synchronization between the senders, and (c) be integrated easily with TCP. Furthermore, we propose the Hierarchical Network Coding (HNC) technique to be used with scalable video bit stream to combat bandwidth fluctuation on the Internet. Simulation results demonstrate that our proposed scheme can result in bandwidth saving up to 40% for many cases over the traditional schemes.
As broadband Internet becomes widely available, multimedia applications over the Internet become ... more As broadband Internet becomes widely available, multimedia applications over the Internet become increasingly popular. However, packet loss, delay, and time-varying bandwidth of the Internet have remained the major problems for multimedia streaming applications. As such, a number of approaches, including network infrastructure and protocol, source and channel coding have been proposed to either overcome or alleviate these drawbacks of the Internet. In this paper, we propose the MultiTCP system, a receiverdriven, TCP-based system for multimedia streaming over the Internet. Our proposed algorithm aims at providing resilience against SHORT TERM insufficient bandwidth by using MULTIPLE TCP connections for the same application. Furthermore, our proposed system enables the application to achieve and control the desired sending rate during congested periods, which cannot be achieved using traditional TCP. Finally, our proposed system is implemented at the application layer, and hence, no kernel modification to TCP is necessary. We analyze the proposed system, and present simulation results to demonstrate its advantages over the traditional single TCP based approach.
Uploads
Papers by Thinh Nguyen