Medium access control protocols using directional antennas in ad hoc networks
26 Mar 2000-Vol. 1, pp 13-21
TL;DR: This paper attempts to design new MAC protocols suitable for ad hoc networks based on directional antennas, such as the IEEE 802.11 standard, which do not benefit when using directional antennas because they have been designed for omnidirectional antennas.
Abstract: 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 been designed for omnidirectional antennas. In this paper, we attempt to design new MAC protocols suitable for ad hoc networks based on directional antennas.
Citations
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TL;DR: This paper presents a detailed study on recent advances and open research issues in WMNs, followed by discussing the critical factors influencing protocol design and exploring the state-of-the-art protocols for WMNs.
4,205 citations
Cites background from "Medium access control protocols usi..."
...For directional and smart antennas, many MAC protocols have been proposed for ad hoc networks [144,105,82,36]....
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...However, directional antennas bring challenges to the MAC protocol design [144,105,82,36]....
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...Two major schemes exist in this category: MAC based on directional antenna [82,36] and MAC with power control [112]....
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Patent•
03 Oct 2006
TL;DR: In this paper, the authors propose a method for providing unequal allocation of rights among agents while operating according to fair principles, comprising assigning a hierarchal rank to each agent, providing a synthetic economic value to a first set of agents at the a high level of the hierarchy, allocating portions of the synthetic economy value by the first sets of agents to a second subset of agents, at respectively different hierarchal ranks than the first set, and conducting an auction amongst agents using the synthetic economic values as the currency.
Abstract: A method for providing unequal allocation of rights among agents while operating according to fair principles, comprising assigning a hierarchal rank to each agent; providing a synthetic economic value to a first set of agents at the a high level of the hierarchy; allocating portions of the synthetic economic value by the first set of agents to a second set of agents at respectively different hierarchal rank than the first set of agents; and conducting an auction amongst agents using the synthetic economic value as the currency. A method for allocation among agents, comprising assigning a wealth generation function for generating future wealth to each of a plurality of agents, communicating subjective market information between agents, and transferring wealth generated by the secure wealth generation function between agents in consideration of a market transaction. The method may further comprise the step of transferring at least a portion of the wealth generation function between agents.
850 citations
TL;DR: These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.
Abstract: Recent research results have demonstrated the feasibility of full-duplex wireless communication for short-range links. Although the focus of the previous works has been active cancellation of the self-interference signal, a majority of the overall self-interference suppression is often due to passive suppression, i.e., isolation of the transmit and receive antennas. We present a measurement-based study of the capabilities and limitations of three key mechanisms for passive self-interference suppression: directional isolation, absorptive shielding, and cross-polarization. The study demonstrates that more than 70 dB of passive suppression can be achieved in certain environments, but also establishes two results on the limitations of passive suppression: (1) environmental reflections limit the amount of passive suppression that can be achieved, and (2) passive suppression, in general, increases the frequency selectivity of the residual self-interference signal. These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.
794 citations
23 Sep 2002
TL;DR: The design focuses on using multi-hop RTSs to establish links between distant nodes, and then transmit CTS, DATA and ACK over a single hop, and shows that the directional MAC protocol can perform better than IEEE 802.11, although the performance is dependent on the topology configuration and the flow patterns.
Abstract: 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 other's vicinity may potentially communicate simultaneously, depending on the directions of transmission. This can increase spatial reuse of the wireless channel. In addition, the higher gain of directional antennas allows a node to communicate with other nodes located far away, implying that messages could be delivered to the destination in fewer hops. In this paper, we propose a MAC protocol that exploits the characteristics of directional antennas. Our design focuses on using multi-hop RTSs to establish links between distant nodes, and then transmit CTS, DATA and ACK over a single hop. Results show that our directional MAC protocol can perform better than IEEE 802.11, although we find that the performance is dependent on the topology configuration and the flow patterns in the system.
774 citations
01 Oct 2001
TL;DR: A broad-based examination of this potential, focusing on exploiting the longer ranges as well as the reduced interference that beamforming antennas can provide, considers a number of enhancements to a convectional ad hoc network system, and evaluation the impact of each enhancement using simulation.
Abstract: Beamforming antennas have the potential to provide a fundamental breakthrough in ad hoc network capacity. We present a broad-based examination of this potential, focusing on exploiting the longer ranges as well as the reduced interference that beamforming antennas can provide. We consider a number of enhancements to a convectional ad hoc network system, and evaluation the impact of each enhancement using simulation. Such enhancements include "aggressive" and "conservative" channel access models for beamforming antennas, link power control, and directional neighbor discovery. Our simulations are based on detailed modeling on detailed modeling of steered as well as swiched beams using antenna patterns of varying gains, and a realistic radio and propagation model. For the scenarios studied, our results show that beamforming can yield a 28% to 118% (depending upon the density) improvement in throughput, and up to a factor-of-28 reduction in delay. Our study also tells us which mechanisms are likely to be more effective and under what conditions, which in turn identifies areas where future research is neede
680 citations
Cites background from "Medium access control protocols usi..."
...More recently [3] present several medium access control protocols for xed directional antennas....
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References
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25 Oct 1998
TL;DR: The results of a derailed packet-levelsimulationcomparing fourmulti-hopwirelessad hoc networkroutingprotocols, which cover a range of designchoices: DSDV,TORA, DSR and AODV are presented.
Abstract: An ad hoc networkis a collwtion of wirelessmobilenodes dynamically forminga temporarynetworkwithouttheuseof anyexistingnetworkirrfrastructureor centralizedadministration.Dueto the limitedtransmissionrange of ~vlrelessnenvorkinterfaces,multiplenetwork“hops”maybe neededfor onenodeto exchangedata ivithanotheracrox thenetwork.Inrecentyears, a ttiery of nelvroutingprotocols~geted specificallyat this environment havebeen developed.but little pcrfomrartwinformationon mch protocol and no ralistic performancecomparisonbehvwrrthem ISavailable. ~Is paper presentsthe results of a derailedpacket-levelsimulationcomparing fourmulti-hopwirelessad hoc networkroutingprotocolsthatcovera range of designchoices: DSDV,TORA, DSR and AODV. \Vehave extended the /~r-2networksimulatorto accuratelymodelthe MACandphysical-layer behaviorof the IEEE 802.1I wirelessLANstandard,includinga realistic wtrelesstransmissionchannelmodel, and present the resultsof simulations of net(vorksof 50 mobilenodes.
5,147 citations
"Medium access control protocols usi..." refers methods in this paper
...To evaluate our protocols, we performed simulations using an extended version of the UCB/LBNL network simulator, ns-2[3], [6]....
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25 Oct 1998
TL;DR: An approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks is suggested.
Abstract: 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 report suggests an approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks.
2,854 citations
"Medium access control protocols usi..." refers background in this paper
...For instance, routing performance could be improved by using a directional antenna (for route discovery [10] or for data delivery)....
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01 Jan 1999
TL;DR: The characteristics of Mobile Ad hoc Networks (MANETs), and their idiosyncrasies with respect to traditional, hardwired packet networks, are described, with an emphasis on routing performance evaluation considerations.
Abstract: This memo first describes the characteristics of Mobile Ad hoc Networks (MANETs), and their idiosyncrasies with respect to traditional, hardwired packet networks. It then discusses the effect these differences have on the design and evaluation of network control protocols with an emphasis on routing performance evaluation considerations.
2,115 citations
01 Oct 1994
TL;DR: This paper studies media access protocols for a single channel wireless LAN being developed at Xerox Corporation's Palo Alto Research Center and develops a new protocol, MACAW, which uses an RTS-CTS-DS-DATA-ACK message exchange and includes a significantly different backoff algorithm.
Abstract: In recent years, a wide variety of mobile computing devices has emerged, including portables, palmtops, and personal digital assistants. Providing adequate network connectivity for these devices will require a new generation of wireless LAN technology. In this paper we study media access protocols for a single channel wireless LAN being developed at Xerox Corporation's Palo Alto Research Center. We start with the MACA media access protocol first proposed by Karn [9] and later refined by Biba [3] which uses an RTS-CTS-DATA packet exchange and binary exponential back-off. Using packet-level simulations, we examine various performance and design issues in such protocols. Our analysis leads to a new protocol, MACAW, which uses an RTS-CTS-DS-DATA-ACK message exchange and includes a significantly different backoff algorithm.
2,000 citations
"Medium access control protocols usi..." refers background in this paper
...While modern MAC protocols for omnidirectional antennas have taken this problem into account [4], [8], [16], it is not adequately considered in previous studies of using directional antennas in packet radio networks....
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01 Jan 1990
TL;DR: A new scheme, Multiple Access with Collision Avoidance (MACA), that could greatly relieve problems of the existing Carrier Sense Multiple Access method and also be easily extended to provide automatic transmitter power control.
Abstract: n a The existing Carrier Sense Multiple Access (CSMA) method widely used i mateur packet radio on shared simplex packet radio channels frequently suffers from l the well-known "hidden terminal problem" and the less well known but related prob em of the "exposed terminal." This paper proposes a new scheme, Multiple Access c with Collision Avoidance (MACA), that could greatly relieve these problems. MACA an also be easily extended to provide automatic transmitter power control. This could increase the carrying capacity of a channel substantially.
1,562 citations
"Medium access control protocols usi..." refers background in this paper
...While modern MAC protocols for omnidirectional antennas have taken this problem into account [4], [8], [16], it is not adequately considered in previous studies of using directional antennas in packet radio networks....
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