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We present a practical, measurement-based model that captures the effect of interference in 802.11-based wireless LAN or mesh networks. <i>The goal is to model capacity of any given link in the presence of any given number of interferers in a deployed network, carrying any specified amount of offered load</i>. Central to our modeling approach is a MAC-layer(More)
— The IEEE 802.16 WiMax standard provides a mechanism for creating multi-hop mesh, which can be deployed as a high speed wide-area wireless network. To realize the full potential of such high-speed IEEE 802.16 mesh networks, two efficient wireless radio resource allocation extensions were developed. The objective of this paper is to propose an efficient(More)
Wireless 802.11 hotspots have grown in an uncoordinated fashion with highly variable deployment densities. Such uncoordinated deployments, coupled with the difficulty of implementing coordination protocols, has often led to conflicting configurations (e.g., in choice of transmission power and channel of operation) among the corresponding Access Points(More)
—802.11a, b, and g standards were designed for deployment in cooperative environments, and hence do not include mechanisms to protect from jamming attacks. In this paper, we explore how to protect 802.11 networks from jamming attacks by having the legitimate transmission hop among channels to hide the transmission from the jammer. Using a combination of(More)
—In the recent past, there has been a tremendous increase in the popularity of VoIP services as a result of huge growth in broadband access. The same voice-over-Internet protocol (VoIP) service poses new challenges when deployed over a wireless mesh network, while enabling users to make voice calls using WiFi phones. Packet losses and delay due to(More)
— Performance in multihop wireless networks is known to degrade with the number of hops for both TCP and UDP traffic. For VoIP, the wireless network presents additional challenges as the perceived quality is dependent on both loss and delay. We investigate several methods to improve voice quality and present experimental results from an 802.11b testbed(More)
— MPLS has been proposed as an efficient mechanism for traffic engineering in networks to properly account for and utilize network resources. A fundamental problem in MPLS is to reduce the label space usage by label switched paths (LSPs), while meeting the requirements of the flows traversing the network. Using multipoint-to-point LSP trees has been(More)
—Real-time services such as VoIP are becoming popular and are major revenue earners for network service providers. These services are no longer confined to the wired domain and are being extended over wireless networks. Although some of the existing wireless technologies can support some low-bandwidth applications, the bandwidth demands of many multimedia(More)
— We present SPIDER – a system for fast replication or distribution of large content from a single source to multiple sites interconnected over Internet or via a private network. In order to exploit spatial diversity of the underlying network, SPIDER uses an overlay structure composed of dedicated Transit Nodes (TNs). The data transport mechanism in SPIDER(More)