A Multi-channel MAC Layer Protocol with Dynamic Bandwidth Allocation for Ad Hoc Networks PDF Download

Author: Manasi Velhankar
Publisher:
ISBN:
Category : Ad hoc networks (Computer networks)
Languages : en
Pages : 104

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Author: Subir Kumar Sarkar
Publisher: CRC Press
ISBN: 1466514469
Category : Computers
Languages : en
Pages : 353

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Book Description
The military, the research community, emergency services, and industrial environments all rely on ad hoc mobile wireless networks because of their simple infrastructure and minimal central administration. Now in its second edition, Ad Hoc Mobile Wireless Networks: Principles, Protocols, and Applications explains the concepts, mechanism, design, and performance of these highly valued systems. Following an overview of wireless network fundamentals, the book explores MAC layer, routing, multicast, and transport layer protocols for ad hoc mobile wireless networks. Next, it examines quality of service and energy management systems. Additional chapters cover mobility models for multi-hop ad hoc wireless networks as well as cross-layer design issues. Exploring Bluetooth, IrDA (Infrared Data Association), HomeRF, WiFi, WiMax, Wireless Internet, and Mobile IP, the book contains appropriate examples and problems at the end of each chapter to illustrate each concept. This second edition has been completely updated with the latest technology and includes a new chapter on recent developments in the field, including sensor networks, personal area networks (PANs), smart dress, and vehicular ad hoc networks. Self-organized, self-configured, and self-controlled, ad hoc mobile wireless networks will continue to be valued for a range of applications, as they can be set up and deployed anywhere and anytime. This volume captures the current state of the field as well as upcoming challenges awaiting researchers.

Author: Yogita Mehta
Publisher:
ISBN:
Category :
Languages : en
Pages : 94

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Book Description
[Author's abstract] Recent technology advances have opened a new spectrum of communication networks called ad hoc networks. In an ad hoc network, the Media Access Control (MAC) protocol of IEEE 802.11 Distributed Coordination Function (DCF), designed to share a single channel between nodes. This thesis presents a protocol that facilitates use of more than one channel and analytical analysis for the throughput of the network. One of the functions of a MAC layer is to scan all channels. A composite metric (CM) has been proposed for each available channel. The CM depends on the signal to noise ratio, the battery power remaining and the mobility of each node with respect to other nodes in the network. The channels with three higher CMs are selected at each node and are used to build a Preferred Channel List (PCL). During Announcement Traffic Indication Message (ATIM), the PCL is sent by the node intended to communicate with another node. If the PCL of the receiver node has non interfering channels with the PCL of the sender node, it responds with an ATIM ACK with its PCL. If the PCL of both nodes have appropriate channels, then the sender node replies with an ATIM RES indicating that at the end of the ATIM window, the RTS/CTS/DATA/ACK handshake will begin. A mathematical model based on Markov chain process is designed to derive an expression for saturation throughput and evaluate the performance of Composite Metric (CM) based Multi channel MAC (MMAC) against IEEE 802.11 MAC Distributed Co ordination Function (DCF) and Dynamic Channel Allocation (DCA) protocol. IEEE 802.11 MAC, DCA and CM based MMAC protocol works better for large data packets than for small data packets. Simulation results show enhancement of 35 to 95 percent in the overall throughput of the network when the proposed CM based MMAC protocol used over IEEE 802.11 MAC and DCA protocols.

Author: Marzieh Veyseh
Publisher:
ISBN:
Category :
Languages : en
Pages : 394

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Author: Imran Haider Gulam Haider Balsania
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Book Description
A SINR based MAC layer protocol for multi-channel ad-hoc networks is proposed. The protocol provides a distributed solution to a node pair that has to choose the "best" channel amongst the available 'M' channels (M>1). We define "best channel selection" in terms of the least interference power measurement encountered on a particular channel by the receiving station throughout the entire duration of data exchange. Using Medium Access Control (MAC) layer mechanisms for message exchange between the nodes, our algorithm achieves not only interference mitigation but also solves the classical hidden and exposed terminal problems in wireless networks. Simulations performed on the NS-2 platform validate the throughput gain achieved by our algorithm in comparison to IEEE 802.11 MAC scheme alongside two other state-of-the-art multichannel MAC protocols.

Author: Yan Zhang
Publisher: CRC Press
ISBN: 1420013548
Category : Computers
Languages : en
Pages : 610

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Book Description
A promising new technology, wireless mesh networks are playing an increasingly important role in the future generations of wireless mobile networks. Characterized by dynamic self-organization, self-configuration, and self-healing to enable quick deployment, easy maintenance, low cost, high scalability, and reliable services, this technology is beco

Author: Yun-Jung Lu
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Book Description

Author: Yuhan Moon
Publisher:
ISBN:
Category : Ad hoc networks (Computer networks)
Languages : en
Pages : 151

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Book Description
Today, many wireless networks are single-channel systems. However, as the interest in wireless services increases, the contention by nodes to occupy the medium is more intense and interference worsens. One direction with the potential to increase system throughput is multi-channel systems. Multi-channel systems have been shown to reduce collisions and increase concurrency thus producing better bandwidth usage. However, the well-known hidden- and exposed-terminal problems inherited from single-channel systems remain, and a new channel selection problem is introduced. In this dissertation, Multi-channel medium access control (MAC) protocols are proposed for mobile ad hoc networks (MANETs) for nodes equipped with a single half-duplex transceiver, using more sophisticated physical layer technologies. These include code division multiple access (CDMA), orthogonal frequency division multiple access (OFDMA), and diversity. CDMA increases channel reuse, while OFDMA enables communication by multiple users in parallel. There is a challenge to using each technology in MANETs, where there is no fixed infrastructure or centralized control. CDMA suffers from the near-far problem, while OFDMA requires channel synchronization to decode the signal. As a result CDMA and OFDMA are not yet widely used. Cooperative (diversity) mechanisms provide vital information to facilitate communication set-up between source-destination node pairs and help overcome limitations of physical layer technologies in MANETs. In this dissertation, the Cooperative CDMA-based Multi-channel MAC (CCM-MAC) protocol uses CDMA to enable concurrent transmissions on each channel. The Power-controlled CDMA-based Multi-channel MAC (PCC-MAC) protocol uses transmission power control at each node and mitigates collisions of control packets on the control channel by using different sizes of the spreading factor to have different processing gains for the control signals. The Cooperative Dual-access Multi-channel MAC (CDM-MAC) protocol combines the use of OFDMA and CDMA and minimizes channel interference by a resolvable balanced incomplete block design (BIBD). In each protocol, cooperating nodes help reduce the incidence of the multi-channel hidden- and exposed-terminal and help address the near-far problem of CDMA by supplying information. Simulation results show that each of the proposed protocols achieve significantly better system performance when compared to IEEE 802.11, other multi-channel protocols, and another protocol CDMA-based.

Author: 胡麗君
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

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Book Description

Author: Afef Sayadi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Wireless multi-hop ad hoc and sensor networks provide a promising solution to ensure ubiquitous connectivity for the Future Internet. Good network connectivity requires designing a reliable Medium Access Control (MAC) protocol, which is a challenging task in the ad hoc and sensor environments. The broadcast and shared nature of the wireless channel renders the bandwidth resources limited and expose the transmissions to relatively high collisions and loss rates. The necessity to provide guaranteed Quality of Service (QoS) to the upper layers triggered the design of conflict-free MAC protocols. The TDMA synchronization constraint is basically behind the rush of MAC protocol design based on a fixed frame size. This design shows inflexibility towards network variations and creates a network dimensioning issue that leads to a famine risk in case the network is under-dimensioned, and to a waste of resources, otherwise. Moreover, the alternative dynamic protocols provide more adaptive solutions to network topology variations at the expense of a fair access to the channel. Alongside with the efficient channel usage and the fair medium access, reducing the energy consumption represents another challenge for ad hoc and sensor networks. Solutions like node activity scheduling tend to increase the network lifetime while fulfilling the application requirements in terms of throughput and delay, for instance. Our contributions, named OSTR and S-OSTR, address the shortcomings of the medium access control protocol design in the challenging environment of wireless multi-hop ad hoc and sensor networks, respectively. For OSTR the idea consists in adopting a dynamic TDMA frame size that increases slot-by-slot according to the nodes arrival/departure to/from the network, and aiming to achieve a minimum frame size. For this end, OSTR couples three major attributes: (1) performing slot-by-slot frame size increase, (2) providing a spatial reuse scheme that favors the reuse of the same slot if possible, (3) and ensuring an on-demand frame size increase only according to the node requirements in terms of throughput. To tackle different frame sizes co-existence in the network, OSTR brings a cooperative solution that consists in fixing an appointment, a date when the frame size in the network is increased. Concerning S-OSTR, it is an amendment of OSTR for wireless sensor networks. It brings the idea of a dynamic active period, since it deploys a dynamic frame size that is built slot-by-slot according to nodes arrival to the network. S-OSTR enforces the slot-by-slot frame size increase by a node activity scheduling to prolong the inactivity period in the network, and hence prolong the overall network lifetime for wireless sensor networks. Our contributions are both based on the new dynamic TDMA frame size increase that consists in increasing the frame size slot-by-slot aiming to achieve a shorter frame size, and hence improve the channel utilization, and reduce the energy consumption. The performance analysis of OSTR and S-OSTR shows that they present good potentials to support QoS requirements, to provide energy-efficiency, to ensure fair medium access, to accommodate network topology changes and finally, to enhance robustness against scalability. The impact of this new TDMA frame size increase technique on the medium access control protocol performance is highlighted through multiple simulations of OSTR and S-OSTR. Multiple comparative studies are also handled to point out the effectiveness of this new technique and the soundness of our contributions.