Wireless Networks

Laptops are vulnerable to theft, greatly increasing the likelihood of exposing sensitive files. Unfortunately, storing data in a cryptographic file system does not fully address this problem. Such systems ask the user to imbue them with long-term ...

An ad hoc network is a group of wireless mobile computers (or nodes), in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range. Prior research in ad hoc networking ...

The IEEE 802.11 wireless media access standard supports multiple data rates at the physical layer. Moreover, various auto rate adaptation mechanisms at the medium access layer have been proposed to utilize this multi-rate capability by automatically ...

This paper presents a power control MAC protocol that allows nodes to vary transmit power level on a per-packet basis. Several researchers have proposed simple modifications of IEEE 802.11 to incorporate power control. The main idea of these power ...

Directional antennas can adaptively select radio signals of interest in specific directions, while filtering out unwanted interference from other directions. A couple of medium access protocols based on random access schemes have been proposed for ...

Wireless link losses result in poor TCP throughput since losses are perceived as congestion by TCP, resulting in source throttling. In order to mitigate this effect, 3G wireless link designers have augmented their system with extensive local ...

Due to the availability of a wide variety of wireless access technologies, a mobile host can potentially have subscriptions and access to more than one wireless network at a given time. In this paper, we consider such a multi-homed mobile host, and ...

Understanding usage patterns in wireless local-area networks (WLANs) is critical for those who develop, deploy, and manage WLAN technology, as well as those who develop systems and application software for wireless networks. This paper presents results ...

On many battery-powered mobile computing devices, the wireless network is a significant contributor to the total energy consumption. In this paper, we investigate the interaction between energy-saving protocols and TCP performance for Web-like ...

We consider a problem of broadcast communication in sensor networks, in which samples of a random field are collected at each node, and the goal is for all nodes to obtain an estimate of the entire field within a prescribed distortion value. The main ...

Sink mobility brings new challenges to data dissemination in large sensor networks. It suggests that information about each mobile sink's location be continuously propagated throughout the sensor field in order to keep all sensors informed of the ...

In all-wireless networks, minimizing energy consumption is crucial as in most cases the nodes are battery-operated. We focus on the problem of power-optimal broadcast, for which it is well known that the broadcast nature of radio transmissions can be ...

A key subproblem in the construction of location-aware systems is the determination of the position of a mobile device. This article describes the design, implementation and analysis of a system for determining position inside a building from measured ...