Results 1 - 10 of 2,772

OAR: An Opportunistic Auto-rate Media Access

by B. Sadeghi, V. Kanodia, A. Sabharwal, E. Knightly - ACM Mobicom , 2005
"... 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 adapting the transmission rate to best match the c ..."
Abstract - Cited by 40 (1 self) - Add to MetaCart
the channel conditions. In this paper, we introduce the Opportunistic Auto Rate (OAR) protocol to better exploit durations of high-quality channels conditions. The key mechanism of the OAR protocol is to opportunistically send multiple back-to-back data packets whenever the channel quality is good. As channel

MOAR: A Multi-channel Opportunistic Auto-rate Media Access Protocol for Ad Hoc Networks

by V. Kanodia, A. Sabharwal, E. Knightly
"... The IEEE 802.11 wireless media standard supports multiple frequency channels as well as multiple data rates at the physical (PHY) layer. Moreover, various auto rate adaptation mechanisms at the medium access layer have been proposed to exploit the multi-rate capabilities of IEEE 802.11. In this pape ..."
Abstract - Cited by 39 (1 self) - Add to MetaCart
.11. In this paper we introduce Multichannel Opportunistic Auto Rate (MOAR), an enhanced MAC protocol for multi-channel and multi-rate IEEE 802.11 enabled wireless ad hoc networks to opportunistically exploit the presence of frequency diversity (in the form of multiple frequency channels). The key mechanism of MOAR

Opportunistic Media Access for Multirate Ad Hoc Networks

by B. Sadeghi, V. Kanodia, A. Sabharwal, E. Knightly , 2002
"... 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 adapting the transmission rate to best match the c ..."
Abstract - Cited by 332 (12 self) - Add to MetaCart
the channel conditions. In this paper, we introduce the Opportunistic Auto Rate (OAR) protocol to better exploit durations of high-quality channels conditions. The key mechanism of the OAR protocol is to opportunistically send multiple back-to-back data packets whenever the channel quality is good. As channel

ExOR: Opportunistic Multi-Hop Routing for Wireless Networks

by Sanjit Biswas, Robert Morris - in SIGCOMM , 2005
"... This paper describes ExOR, an integrated routing and MAC protocol that increases the throughput of large unicast transfers in multi-hop wireless networks. ExOR chooses each hop of a packet’s route after the transmission for that hop, so that the choice can reflect which intermediate nodes actually r ..."
Abstract - Cited by 457 (0 self) - Add to MetaCart
received the transmission. This deferred choice gives each transmission multiple opportunities to make progress. As a result ExOR can use long radio links with high loss rates, which would be avoided by traditional routing. ExOR increases a connection’s throughput while using no more network capacity than

A Rate-Adaptive MAC Protocol for Multi-Hop Wireless Networks

by Gavin Holland, Nitin H. Vaidya, Paramvir Bahl , 2001
"... 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 bring ..."
Abstract - Cited by 484 (5 self) - Add to MetaCart
relatively few proposals for W-LANs. In this paper we present a rate adaptive MAC protocol called the Receiver-Based AutoRate (RBAR) protocol. The novelty of RBAR is that its rate adaptation mechanism is in the receiver instead of in the sender. This is in contrast to existing schemes in devices like

Opportunistic spectral usage: Bounds and a multi-band CSMA/CA protocol

by Ashutosh Sabharwal, Ahmad Khoshnevis, Edward Knightly - IEEE/ACM Transactions on Networking , 2006
"... Abstract — In this paper, we study the gains from opportunistic spectrum usage when neither sender or receiver are aware of the current channel conditions in different frequency bands. Hence to select the best band for sending data, nodes first need to measure the channel in different bands which ta ..."
Abstract - Cited by 63 (1 self) - Add to MetaCart
beneficial in low signal to noise scenarios, which are typically the cases when the node throughput in single-band (no opportunism) system is the minimum. To study the impact of opportunism on network throughput, we devise a CSMA/CA protocol, Multiband Opportunistic Auto Rate (MOAR), which implements

ABSTRACT Opportunistic Media Access for Multirate

by B. Sadeghi, V. Kanodia, A. Sabharwal, E. Knightly
"... 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 adapting the transmission rate to best match the c ..."
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the channel conditions. In this paper, we introduce the Opportunistic Auto Rate (OAR) protocol to better exploit durations of high-quality channels conditions. The key mechanism of the OAR protocol is to opportunistically send multiple back-to-back data packets whenever the channel quality is good. As channel

Robust rate adaptation for 802.11 wireless networks

by Starsky H. Y. Wong, Hao Yang, Songwu Lu, Vaduvur Bharghavan - in ACM Mobicom , 2006
"... Rate adaptation is a mechanism unspecified by the 802.11 standards, yet critical to the system performance by exploiting the multi-rate capability at the physical layer. In this paper, we conduct a systematic and experimental study on rate adaptation over 802.11 wireless networks. Our main contribut ..."
Abstract - Cited by 191 (3 self) - Add to MetaCart
must accurately estimate the channel condition despite the presence of various dynamics caused by fading, mobility and hidden terminals. Second, we design and implement a new Robust Rate Adaptation Algorithm (RRAA) that addresses the above challenge. RRAA uses short-term loss ratio to opportunistically

A Congestion-aware Medium Access Control Protocol for Multi-rate Ad-hoc Networks

by Timo Zauner, Luke Haslett
"... This paper investigates the problem of how to improve TCP performance in multi-rate Ad-hoc networks with congested links. To improve network performance, different rate adaptation algorithms, such as Automatic Rate Fallback (ARF) and Receiver-Based AutoRate (RBAR), have been proposed to adapt the da ..."
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the data rate according to the current channel quality. Opportunistic Auto Rate (OAR) protocol is an optimisation for any existing rate adaptation algorithm which leads to a significant performance gain by providing temporal fairness. We analyze the reasons for the high performance gain obtained using OAR

Opportunistic Fair Scheduling over Multiple Wireless Channels

by Yonghe Liu, Edward Knightly , 2003
"... Emerging spread spectrum high-speed data networks utilize multiple channels via orthogonal codes or frequency-hopping patterns such that multiple users can transmit concurrently. In this paper, we develop a framework for opportunistic scheduling over multiple wireless channels. With a realistic chan ..."
Abstract - Cited by 111 (4 self) - Add to MetaCart
Emerging spread spectrum high-speed data networks utilize multiple channels via orthogonal codes or frequency-hopping patterns such that multiple users can transmit concurrently. In this paper, we develop a framework for opportunistic scheduling over multiple wireless channels. With a realistic
Results 1 - 10 of 2,772