Nitin H. Vaidya

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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)
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)
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)
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)
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)
Wireless technologies, such as IEEE 802.11a, that are used in ad hoc networks provide for multiple non-overlapping channels. Most ad hoc network protocols that are currently available are designed to use a single channel. However, the available network capacity can be increased by using multiple channels. This paper presents new protocols specifically(More)
Multiple channels are available for use in IEEE 802.11. Multiple channels can increase the available network capacity, but require new protocols to exploit the available capacity. This paper studies the problem of improving the capacity of multi-channel wireless networks by using multiple interfaces. We consider the scenario when multiple interfaces are(More)
This paper studies how the capacity of a static multi-channel network scales as the number of nodes, <i>n</i>, increases. Gupta and Kumar have determined the capacity of single-channel networks, and those bounds are applicable to multi-channel networks as well, provided each node in the network has a dedicated interface per channel.In this work, we(More)