Seungjoon Lee

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We introduce PRM (Probabilistic Resilient Multicast): a multicast data recovery scheme that improves data delivery ratios while maintaining low end-to-end latencies. PRM has both a proactive and a reactive component; in this paper we describe how PRM can be used to improve the performance of application-layer multicast protocols, especially when there are(More)
We propose a new link metric called <i>normalized advance (NADV)</i> for geographic routing in multihop wireless networks. NADV selects neighbors with the optimal trade-off between proximity and link cost. Coupled with the local next hop decision in geographic routing, NADV enables an adaptive and efficient cost-aware routing strategy. Depending on the(More)
Network Functions Virtualization (NFV) was recently proposed to improve the flexibility of network service provisioning and reduce the time to market of new services. By leveraging virtualization technologies and commercial off-theshelf programmable hardware, such as general purpose servers, storage and switches, NFV decouples the software implementation of(More)
IPTV service providers offering Video-on-Demand currently use servers at each metropolitan office to store all the videos in their library. With the rapid increase in library sizes, it will soon become infeasible to replicate the entire library at each office. We present an approach for intelligent content placement that scales to large library sizes (e.g.,(More)
Partial packet recovery protocols attempt to repair corrupted packets instead of retransmitting them in their entirety. Recent approaches have used physical layer confidence estimates or additional error detection codes embedded in each transmission to identify corrupt bits, or have applied forward error correction to repair without such explicit knowledge.(More)
Understanding the channel popularity or content popularity is an important step in the workload characterization for modern information distribution systems (e.g., World Wide Web, peer-to-peer file-sharing systems, video-on-demand systems). In this paper, we focus on analyzing the channel popularity in the context of Internet Protocol Television (IPTV). In(More)
We consider the channel assignment problem for multihop wireless networks in which nodes have multiple interfaces. Given the number of interfaces at each node and available channels in the system, we find a feasible channel assignment to improve network performance. Even when routing is given, finding a channel assignment for optimal performance is NP-hard.(More)
Internet Protocol Television (IPTV) has emerged as a new delivery method for TV. In contrast with native broadcast in traditional cable and satellite TV system, video streams in IPTV are encoded in IP packets and distributed using IP unicast and multicast. This new architecture has been strategically embraced by ISPs across the globe, recognizing the(More)