Download or read book Composite Metric Based Multi channel MAC Protocol for Ad hoc Network written by Yogita Mehta and published by . This book was released on 2005 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: [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.

Download or read book Cooperative Multi channel MAC Protocols for Wireless Ad Hoc Networks written by Yuhan Moon and published by . This book was released on 2010 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A SINR Based MAC Layer Protocol for Multi channel Ad hoc Networks written by Imran Haider Gulam Haider Balsania and published by . This book was released on 2010 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A New Multichannel MAC Protocol for Ad Hoc Networks Based on Two phase Coding with Power Control TPCPC written by and published by . This book was released on with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a new CDMA-based multichannel medium access control protocol for ad hoc networks, which is named as two-phase coding multichannel protocol with power control. The first phase code is used to broaden the area reuse and the second phase code is employed to distinguish between different nodes in one specific area. This algorithm efficiently eliminates hidden terminal and exposed terminal problems during data transmission and greatly increases the throughput. In addition, it has good scalability and can be easily accomplished with GPS. Although many multichannel MAC protocols adopting CDMA techniques have been presented, few have addressed the near-far problem. We incorporate power control in our algorithm and reduce the near-far interference. The implementation of two-phase coding with power control is discussed, and the primary simulation result demonstrates that the proposed protocol offers better performance.

Download or read book Control channel Reuse based Multi channel MAC Protocol for Ad Hoc Networks written by Divya Sardana and published by . This book was released on 2009 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ad hoc networks have become a popular type of wireless network in the present world. In order to match with the increasing demand of ad hoc networks, a lot of research is being done towards solving the issues related to the design of ad hoc networks. The design of a Medium Access Control (MAC) protocol for ad hoc networks is one such issue. Traditional MAC protocols involve the use of a single channel as the wireless medium. However, throughput of a single channel MAC degrades as the node traffic in the system increases. One of the interesting approaches towards alleviating this problem is the use of more than one channel as the underlying medium. The use of multiple channels allows more than one communication to take place simultaneously thereby improving the throughput of the system. Multiple channels have been mostly used in the literature by assigning one of the channels as the control channel used only for control packet transfer and the rest of the channels as data channels used for Data packet transfer. Using such an approach towards designing a multi-channel MAC protocol leads to a poor utilization of the available bandwidth. In this thesis, we propose a multi-channel MAC protocol called as Control-channel Reuse based Multi-channel MAC (CRM-MAC) which aims at improving the overall bandwidth utilization. We illustrate the efficacy of our protocol through elaborate simulations.

Download or read book Multichannel Medium Access Control Protocol with Cooperative Channel Selection for Ad Hoc Networks written by Jai Mondhe and published by . This book was released on 2003 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mobile ad hoc network is a collection of mobile terminals equipped with wireless transceivers that form an autonomous network without any pre-planned infrastructure or centralized administration. Wireless hosts in an ad hoc network typically share a single common channel for communication. The Medium Access Control (MAC) allows the hosts to resolve contention while randomly accessing the channel and plays a key role in determining the efficiency of channel usage in the network. Usage of multiple channels improves the throughput of the MAC protocol in ad hoc networks by allowing multiple nodes to transmit concurrently on different non-overlapping channels. Efficient channel selection schemes can reduce the contention in each channel leading to smaller number of collisions, backoffs, and retransmissions. This research explores a new channel selection scheme that is based on maximizing the signal to interference ratio at the receiver as well as minimizing the interference caused to all other active receivers in the vicinity of the sender. An implementation of this "cooperative" channel selection technique is proposed employing receiver-initiated busy-tones and signal power measurements at the sending and receiving nodes respectively. Simulation based performance results are presented.

Download or read book Multi channel MAC Protocols for Wireless Ad Hoc Networks written by Mehdi Ait Tahar and published by . This book was released on 2003 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Cluster based Routing and Multi channel MAC Protocols for Vehicular Ad Hoc Networks written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New cluster-based routing and multi-channel MAC protocols for vehicular ad hoc networks.

Download or read book A New Multi channel MAC Protocol for Wireless Ad Hoc Networks with Single Transceiver written by Musa Aykut Canbolat and published by . This book was released on 2007 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although IEEE 802.11a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. There are some papers challenging this problem. Some of them have requirements that will increase the cost, like requirement of multiple transceivers. Some others address the problem with single transceivers, but are very hard to be employed in highly mobile Ad Hoc networks due to network-wide synchronization requirements. In this Thesis, multiple channel use in a wireless network with single transceiver nodes is addressed, and attempted to be solved with a new efficient Ad Hoc network MAC protocol, which intends to remove the requirement of network-wide synchronization.

Download or read book Throughput Analysis and Enhancement of Multi Channel MAC Protocol in Ad Hoc Networks written by 高譓翔 and published by . This book was released on 2006 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Multi channel MAC Layer Protocol with Dynamic Bandwidth Allocation for Ad Hoc Networks written by Manasi Velhankar and published by . This book was released on 2007 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distributed Dynamic Channel Assignment of Multi channel MAC Protocol in Ad Hoc Network written by 胡麗君 and published by . This book was released on 2007 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Ubiquitous Networking 2 written by Rachid El-Azouzi and published by Springer. This book was released on 2016-11-03 with total page 693 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers the proceedings of the 2nd UNet conference, held in Casablanca May 30 - June 1, 2016. It presents new trends and findings in hot topics related to ubiquitous computing/networking, covered in three tracks and three special sessions: Main Track 1: Context-Awareness and Autonomy Paradigms Track Main Track 2: Mobile Edge Networking and Virtualization Track Main Track 3: Enablers, Challenges and Applications Special Session 1: Smart Cities and Urban Informatics for Sustainable Development Special Session 2: Unmanned Aerial Vehicles From Theory to Applications Special Session 3: From Data to Knowledge: Big Data applications and solutions

Download or read book Multi channel Mac Protocols with Bandwidth Utilization Enhancement in Wireless Ad Hoc Networks written by Yun-Jung Lu and published by . This book was released on 2012 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Medium Access Protocol MAC Design for Wireless Multi hop Ad Hoc and Sensor Networks written by Afef Sayadi and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Overhead Analysis of Location aware Two phase Coding Multi channel MAC Protocol LA TPCMMP for MANETs written by and published by . This book was released on with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a novel location-aware multi-channel medium access control (MAC) protocol for large-scale dense mobile ad hoc networks (MANETs) based on a scalable two-phase coding scheme, where the first-phase code is used to differentiate adjacent cells and the second-phase code is employed to distinguish nodes in one specific cell. It eliminates the hidden terminal problem (HTP) during data transmission without requiring periodical exchange of neighborhood information. Furthermore, we introduce a collision resolution mechanism in the control channel. We analyze the performance of the proposed protocol in terms of control overhead. Its theoretical results are confirmed by simulations and it is demonstrated that the new protocol significantly outperforms the classical code division multiple access (CDMA) based multi-channel MAC protocols.

Download or read book Cluster adaptive Two phase Coding Multi channel MAC Protocol CA TPCMMP for MANETs written by and published by . This book was released on with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper introduces a novel joint clustering and multi-channel medium access control (MAC) protocol for mobile ad hoc networks (MANETs) based on a scalable two-phase coding scheme, where the first-phase code is used for differentiating the clusters and the second-phase code is employed to distinguish the nodes in a specific cluster. It mitigates the hidden terminal problem (HTP) during data transmission and efficiently incorporates the procedure of code assignment with adaptive clustering. We also introduce the connection detection and confliction resolution mechanisms for the allocation of the first-phase code in the control channel. Simulation results show that substantial improvement in terms of control overhead can be achieved by the proposed protocol over the traditional distributed code division multiple access (CDMA) based multi-channel MAC algorithms with clustering or without clustering.