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Wireless local area networks (W-LANs) have become increasingly popular due to the recent availability of affordable devices that are capable of communicating at high data rates. These high rates are possible, in part, through new modulation schemes that are optimized for the channel conditions bringing about a dramatic increase in bandwidth efficiency.(More)
This paper proposes a medium access control (MAC) protocol for ad hoc wireless networks that utilizes multiple channels dynamically to improve performance. The IEEE 802.11 standard allows for the use of multiple channels available at the physical layer, but its MAC protocol is designed only for a single channel. A single-channel MAC protocol does not work(More)
A mobile ad hoc network consists of wireless hosts that may move often. Movement of hosts results in a change in routes, requiring some mechanism for determining new routes. Several routing protocols have already been proposed for ad hoc networks. This paper suggests an approach to utilize location information (for instance, obtained using the global(More)
Fairness is an important issue when accessing a shared wireless channel. With <italic>fair scheduling</italic>, it is possible to allocate bandwidth in proportion to <italic>weights</italic>of the packet <italic>flows</italic> sharing the channel. This paper presents a fully <italic>distributed</italic> algorithm for fair scheduling in a wireless LAN. The(More)
Previous research in wireless ad hoc networks typically assumes the use of omnidirectional antennas at all nodes. With omnidirectional antennas, while two nodes are communicating using a given channel, MAC protocols such as IEEE 802.11 require all other nodes in the vicinity to stay silent. With directional antennas, two pairs of nodes located in each(More)
Mobile ad hoc networks have gained a lot of attention lately as a means of providing continuous network connectivity to mobile computing devices regardless of physical location. Recently, a large amount o f r e-search has focused on the routing protocols needed in such a n e n vironment. In this paper, we i n vesti-gate the eeects that link breakage due to(More)
— Using directional antennas can be beneficial for wireless ad hoc networks consisting of a collection of wireless hosts. To best utilize directional antennas, a suitable Medium Access Control (MAC) protocol must be designed. Current MAC protocols, such as the IEEE 802.11 standard, do not benefit when using directional antennas, because these protocols have(More)
— Selfish hosts in wireless networks that fail to adhere to the MAC protocol may obtain an unfair share of the channel bandwidth. We present modifications to the IEEE 802.11 backoff mechanism to simplify detection of such selfish hosts. We also present a correction scheme for penalizing greedy misbehavior which attempts to restrict the misbehaving nodes to(More)
This paper presents a power control MAC protocol based on the IEEE 802.11 standard. Several researchers have proposed a simple modification of IEEE 802.11 to incorporate power control. The main idea of these power control schemes is to use different power levels for RTS-CTS and DATA-ACK. Specifically, maximum transmit power is used for RTS-CTS, and the(More)