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An enhanced and energy efficient communication architecture for Bluetooth wireless PANs

Ad Hoc Networks 2005年第2期3卷 119-140页

作者： Cordeiro, Carlos De M. Abhyankar, Sachin Agrawal, Dharma P. Networking Technologies Lab. Nokia Research Center Tampere Finland Qualcomm Incorporated San Diego CA United States OBR Ctr. Distributed Mobile Comp. Department of ECECS University of Cincinnati Cincinnati OH United States

Bluetooth is a radio technology for Wireless Personal Area Networking (WPAN) operating in the 2.4 GHz ISM frequency band, and allows devices to be connected into short-range ad hoc networks. The Bluetooth medium access control protocol is based on the Master/Slave paradigm wherein any communication between slave devices has to go through the Master. While this model provides for simplicity, it incurs a longer delay between any two slave devices due to far from optimal packet forwarding, the use of double the bandwidth, and also additional energy wastage at the Master. Moreover, if more than two devices want to communicate as a group, this can only be achieved by either multiple unicast transmissions or a piconet-wide broadcast, clearly resulting in inefficiency. In this paper, we propose a novel Dynamic Slot Assignment (DSA) scheme whereby the Master device dynamically assigns slots to Slaves so as to allow them to communicate directly with each other without any Master intervention. This proposed communication architecture also provides for Quality of Service (QoS) requests, admission control, and multi-device conversation by which a multicast-like communication is implemented within a piconet. Through extensive simulation, we observe that DSA drastically enhances Bluetooth performance in terms of delay and throughput, while significantly reducing power consumption at the master and the overall piconet. © 2004 Elsevier B.V. All rights reserved.

关键词： Radio systems

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Effects of contention window and packet size on the energy efficiency of wireless local area network

Effects of contention window and packet size on the energy e...

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IEEE Conference on Wireless Communications and Networking

作者： Xiaodong Wang Jun Yin D.P. Agrawal OBR center for Distributed and mobile computing ECECS University of Cincinnati Cincinnati OH USA

The paper introduces an analytical model to investigate the energy efficiency of the IEEE 802.11 distributed coordinated function (DCF). Many factors, such as the number of contending nodes, packet size, contention window, packet transmission collision probability and channel condition, that affect the energy efficiency of 802.11 DCF have been considered. We determine the packet transmission probability by a method simpler than the existing Markov chain model. The paper identifies the tradeoff in choosing packet size to optimize the energy efficiency of DCF in error-prone environments. The effects of contention window and packet size on the energy efficiency are obtained for both DCF basic mode and DCF with four-way handshaking. It is shown that under error-prone environments, optimal packet size can improve more on the energy efficiency than optimal contention window. Combining both optimal contention window and optimal packet size can achieve the maximum optimization. To validate our analytical results, we have done extensive simulations, and they seem to match very well with the presented analytical results.

关键词： Energy efficiency Wireless LAN Analytical models Batteries Throughput Power control Protocols Multiaccess communication Performance analysis Delay

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A cross-layer approach for efficient flooding in wireless sensor networks

A cross-layer approach for efficient flooding in wireless se...

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IEEE Conference on Wireless Communications and Networking

作者： Xiaodong Wang Jun Yin Qi Zhang D.P. Agrawal OBR Center for Distributed and Mobile Computing ECECS University of Cincinnati Cincinnati OH USA

Due to the high node density and stringent constraints on the energy consumption in wireless sensor networks, designing an energy efficient flooding scheme with high reachability is critical for the operation and the lifetime of sensor networks. Many existing flooding approaches address the needs of general ad hoc networks. In contrast, this paper presents a cross-layer approach tailored specifically to the needs of sensor networks. Without assuming location awareness, a novel MAC layer access-deferring scheme, based on the received signal power, is proposed to reduce the collision possibility and broadcast redundancy. Local neighborhood information is piggybacked onto the broadcast packet, and exploited to enhance the reachability. Simulation results show that compared with probabilistic flooding, this scheme has good performance in terms of reachability, average delay and energy efficiency. Moreover, we examine how the range estimation error and neighborhood information inaccuracy introduced by the fading environment affects the performance of our flooding scheme.

关键词： Wireless sensor networks Energy efficiency Broadcasting Floods Energy consumption Ad hoc networks mobile radio mobility management Redundancy Delay Estimation error

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Dynamic admission control and QoS for 802.16 wireless MAN

Dynamic admission control and QoS for 802.16 wireless MAN

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Wireless Telecommunications Symposium, WTS

作者： H. Wang W. Li D.P. Agrawal OBR Center for Distributed and Mobile Computing ECECS University of Cincinnati Cincinnati OH USA

IEEE 802.16 wireless MAN is expected to revolutionize of the broadband wireless access technology. The grant/request mechanism in IEEE 802.16 MAC provides different quality of service (QoS) for different service flows. In the paper, we discuss the QoS issue in IEEE 802.16 wireless MANs and propose an admission control scheme for services defined in the 802.16 specifications. Our proposed scheme provides the highest priority for UGS flows and maximizes the bandwidth utilization by bandwidth borrowing and degradation. We also develop an analytical model to evaluate the system performance. Some numerical results are included to provide a better understanding of our scheme.

关键词： Admission control Bandwidth Quality of service Control systems Wireless LAN Broadband antennas Wireless networks mobile computing distributed computing System performance

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Challenges in utilizing aggregate logical sensor units for wireless sensory information networks

Challenges in utilizing aggregate logical sensor units for w...

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2005 IEEE 16th International Symposium on Personal, Indoor and mobile Radio Communications, PIMRC 2005

作者： Kumar, Anup Dhekne, P.S. Agrawal, Dharma P. Lab. CECS University of Louisville Louisville KY 40292 Computer Division Mod Lab. BARC Mumbai India OBR Research Center for Distributed and Mobile Computing ECECS University of Cincinnati Cincinnati OH 45221-0030

ISBN: (纸本)3800729091

Historically, a large number of small and cheaper sensors are deployed to form a sensor network. This paper provides rationale behind using an Aggregate Logical Sensor Unit (ALSU) as a building block in a Wireless Sensory Information network (WSIN). In this architecture, a single ALSU is composed of many off-the-shelf sensor nodes in the manner similar to the Beowulf cluster concept. The highly capable, cost effective and flexible ALSUs built in this manner from several smaller physical sensor nodes, would enable high computation power and built-in reliability for sensor applications. The objective of this paper is to provide an alternative where energy and computation is not a limiting factor in order to achieve the operational objectives of WSIN applications. This paper highlights critical issues that need to be addressed in developing a framework where each ALSU could have the capability to perform required operations as dictated by an underlying application. © 2005 IEEE.

关键词： Wireless sensor networks

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Mobility and routing management for heterogeneous multi-hop wireless networks

Mobility and routing management for heterogeneous multi-hop ...

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2nd IEEE International Conference on mobile Ad-hoc and Sensor Systems, MASS 2005

作者： Xie, Bin Kumar, Anup Cavalcanti, Dave Agrawal, Dharma P. Srinivasan, S. Computer Engineering and Computer Science Dept. University of Louisville Louisville KY 40292 United States Computer Information Systems University of Louisville Louisville KY 40292 United States OBR Center for Distributed Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH 45221-0030 United States

ISBN: (纸本)0780394666

This paper proposes a new Heterogeneous Multi-hop Cellular IP (MCIP) network that integrates multi-hop communication with Cellular IP. MCIP increases the coverage of the wireless network and improves the network robustness against adverse propagation phenomena by supporting communication in dead zones and areas with poor radio coverage. MCIP includes three components: location management, connection management and route reconfiguration. Location management is responsible for maintaining the location information for mobile Stations (MSs) in a local domain. Connection management establishes an initial path for data transmission and a route reconfiguration mechanism is proposed to take advantage of various multi-hop connection alternatives available based on terminal interfaces, network accessibility and topology. Our simulation results show that MCIP performs well in networks of various sizes. © 2005 IEEE.

关键词： Wireless telecommunication systems

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A credit-payment scheme for packet forwarding fairness in mobile ad hoc networks

A credit-payment scheme for packet forwarding fairness in mo...

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IEEE International Conference on Communications (ICC)

作者： Younghwan Yoo Sanghyun Ahn D.P. Agrawal OBR Center for Distributed and Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH USA School of Computer Science University of Seoul Seoul South Korea

Routing protocols for mobile ad hoc networks (MANETs) have assumed that all nodes voluntarily participate in forwarding others' packets. This was a reasonable assumption because all nodes in previous MANETs belonged to a single authority. In the near future, however, a MANET may consist of nodes that belong to multiple organizations since various civilian applications are expected to appear. In this situation, mobile nodes may deliberately avoid packet forwarding to save their own energy, resulting in network partition. To make nodes volunteer in packet forwarding we suggest a payment scheme called protocol-independent fairness algorithm (PIFA). In this type of schemes, nodes need credits to transmit their own packets, and this credit can be earned by forwarding others' packets. PIFA can be utilized irrespective of the type of basic routing protocols, while previous methods are compatible only with source routing like DSR. Simulation results show that PIFA can prevent network partition and network performance degradation due to selfish nodes by inducing them to participate in forwarding packets.

关键词： Intelligent networks mobile ad hoc networks Routing protocols Sprites (computer) Carbon capture and storage mobile computing Computer networks distributed computing Computer science Partitioning algorithms

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A cross-layer approach for designing directional routing protocol in MANETs

A cross-layer approach for designing directional routing pro...

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IEEE Conference on Wireless Communications and Networking

作者： H. Gossain T. Joshi C. Cordeiro D.P. Agrawal OBR Center for Distributed and Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH USA Wireless Communications and Networking Department Philips Research Briarcliff Manor NY USA

In this paper, we propose a directional routing protocol (DRP) for MANETs. DRP is an on-demand directional routing protocol which assumes a cross layer interaction between routing and MAC layer. The main features of DRP include an efficient route discovery mechanism, establishment and maintenance of directional routing and directional neighbor tables (DRT and DNT, respectively), and novel directional route recovery mechanisms. We have implemented DRP on top of an existing MAC protocol for directional antennas and have compared its performance with the popular dynamic source routing (DSR) protocol over both omni-directional and directional antenna models. Preliminary, simulation results are found to be very promising.

关键词： Routing protocols mobile ad hoc networks Media Access Protocol Directional antennas Intelligent networks Cross layer design Access protocols Network topology mobile computing Computer networks

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Route recovery mechanisms for ad hoc networks equipped with switched single beam antennas

Route recovery mechanisms for ad hoc networks equipped with ...

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Annual Symposium on Simulation

作者： T. Joshi H. Gossain C. Cordeiro D.P. Agrawal OBR Center for Distributed and Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH USA Wireless Communications Department Philips Research USA Briarcliff Manor NY USA

In this paper we propose a novel three phase route recovery mechanism for routing over switched single beam directional antennas. We enhance the popular dynamic source routing (DSR) protocol to the underlying directional layer and include an improved broadcast mechanism to facilitate an efficient route discovery. In the event of a link failure, our optimized directional routing protocol (DRP) proceeds in three phases to recover the route to the destination: (i) antenna beam handoff (ii) local route recovery and (iii) zonal route recovery. We have compared the performance of DRP with the DSR protocol over both omnidirectional and directional antenna models in conditions of varying network mobility. Our results clearly indicate that DRP is robust to link failures even in highly mobile scenarios.

关键词： Ad hoc networks Directional antennas Routing protocols Deafness Communication switching Media Access Protocol Signal to noise ratio Network topology mobile computing distributed computing

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Connectivity in multi-radio, multi-channel heterogeneous ad hoc networks

Connectivity in multi-radio, multi-channel heterogeneous ad ...

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IEEE International Symposium on Personal, Indoor and mobile Radio Communications (PIMRC)

作者： D. Cavalcanti H. Gossain D. Agrawal OBR Center for Distributed and Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH USA Mesh Research and Development Group Motorola Inc. Maitland FL USA

Future wireless networks are expected to integrate heterogeneous devices equipped with multiple radios and different characteristics. Therefore, it is important to understand how these heterogeneous radios can affect connectivity and overall multi-hop network performance. In this paper, we study the connectivity of a heterogeneous ad hoc network. We consider two types of nodes: nodes equipped with a single communication interface with communication range r, and dual-mode (DM) nodes, equipped with two communication interfaces with two different communication ranges r and r f , respectively, where r f >r. We assume the radios in the DM nodes operate in two different channels. We provide a theoretical analysis of connectivity in a linear network and we present simulation results for the two-dimensional case that show the impact of DM nodes on connectivity, broadcast latency and robustness in static scenarios

关键词： Intelligent networks Ad hoc networks Delta modulation Analytical models Spread spectrum communication Robustness distributed computing Broadcasting Energy consumption Frequency

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