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We present an experimental performance evaluation study of WiFi links in an open-space outdoor environment. We consider a large scale wireless sensor network scenario of seismic data collection from sensors that are buried in ground and a set of access points (APs) form the hierarchical aggregation layer and the backbone of the network. We conduct two(More)
—We conduct the first detailed measurement analysis of network resource usage and subscriber behavior using a large-scale data set collected inside a nationwide 3G cellular data network. The data set tracks close to a million subscribers over thousands of base stations. We analyze individual subscriber behaviors and observe a significant variation in(More)
Wireless interference is the major cause of degradation of capacity in 802.11 wireless networks. We present an approach to estimate the interference between nodes and links in a live wireless network by passive monitoring of wireless traffic. This does not require any controlled experiments, injection of probe traffic in the network, or even access to the(More)
Cellular data networks are experiencing a serious capacity crunch in the face of exponential increase in mobile data traffic volume. New traffic management techniques are needed to improve network and user perceived performance. In this work, we consider the existence of a higher-layer, agent-based scheduling system that could potentially delay scheduling(More)
—We conduct a detailed measurement analysis to investigate the spatial characteristics of network resource usage using a large-scale data set collected 'in situ' in a nationwide 3G cellular data network. The data set spans over thousands of base stations. We first characterize the spatial correlation in radio resource usage using different statistical(More)
We present a tool to estimate the interference between nodes and links in a live wireless network by passive monitoring of wireless traffic. This tool does not require any controlled experiments, injection of probe traffic in the network, or even access to the network nodes. Our approach requires deploying multiple sniffers across the network to capture(More)
With the advent of programmability in radios, it is becoming easier for wireless network nodes to cheat to obtain an unfair share of the bandwidth. In this work we study the widely used 802.11 protocol and present a solution to detect selfish carrier-sensing behavior where a node raises the CCA (clear channel assessment) threshold for carrier-sensing, or(More)
Given the exponential increase in broadband cellular traffic it is imperative that scalable traffic measurement and monitoring techniques be developed to aid various resource management methods. In this paper, we use a machine learning technique to learn the underlying conditional dependence and independence structure in the base station traffic loads to(More)
—We present an experimental performance evaluation study of WiFi links in an open-space outdoor environment. We consider a large scale wireless sensor network scenario of seismic data collection from sensors that are buried in ground and a set of access points (APs) form the hierarchical aggregation layer and the backbone of the network. We conduct two(More)
Wireless Sensor network (WSN) has added a new dimension in the field of wireless communication. As the sensor nodes are placed at remote places and are equipped with limited sources of battery power, proper energy efficient routing algorithms as well as clustering protocols are highly needed to make the system more energy efficient. Such an energy efficient(More)