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Novel Protocols To Improve Broadcasting Efficiency Over Switched Single Beam Antenna In A Mobile Ad Hoc Network
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Book Synopsis Novel Protocols to Improve Broadcasting Efficiency Over Switched Single Beam Antenna in a Mobile Ad-hoc Network by :
Download or read book Novel Protocols to Improve Broadcasting Efficiency Over Switched Single Beam Antenna in a Mobile Ad-hoc Network written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to fully exploit the benefits of directional communication at upper layers, it is of paramount importance to investigate the issues related to directional broadcasting. Directional antennas offer an increased spatial reuse and a larger coverage range as transmitted power is concentrated in a small angular region. However, in a switched single beam antenna model broadcasting is achieved by sequentially steering the antenna beam across all pre-defined directions resulting in a sweeping delay. In this thesis we study suggested techniques to alleviate broadcast storm problems in ad hoc networks, point out their shortcomings, and propose two new schemes, namely, the New Enhanced Directional Flooding (NEDF) and the Probabilistic Relay Broadcasting (PRB). We thoroughly compare the performance of these protocols with present directional broadcast schemes including omni directional flooding over six, twelve and eighteen antenna beam models. The results indicate that directional broadcasting provides excellent connectivity in the regions of sparse density as compared to omni directional broadcasting. Finally, the proposed schemes are shown to outperform the existing schemes with respect to connectivity, latency and redundancy over a wide spectrum of network topologies and node densities.
Download or read book Proceedings written by and published by . This book was released on 2005 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Hiding Switching Delay and Improving Broadcast Efficiency in Multichannel Multi-interface Wireless Ad Hoc Networks by : Xavier R. Franco
Download or read book Hiding Switching Delay and Improving Broadcast Efficiency in Multichannel Multi-interface Wireless Ad Hoc Networks written by Xavier R. Franco and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multichannel multiradio wireless networks allow one to utilize the available spectrum more efficiently to improve network performance. When nodes operate with multiple channels, the contention among the nodes operating in a particular channel is reduced, which translates to more opportunities to transmit and consequently improved throughput. Among the architectures proposed to implement a multichannel network, the hybrid multichannel protocol has been shown to outperform other strategies with respect to throughput. However, there are still some open problems that have not been studied in detail. One of these is how to improve the efficiency of broadcasting, since currently the hybrid multichannel protocol performs broadcasting by flooding on each channel. Another area that has not been studied enough is the benefits of hiding the switching delay. In this thesis we first propose a smart probabilistic protocol for broadcasting in a multichannel multiradio (MC-MR) wireless network, operating with the hybrid multichannel protocol. We present simulation results that show that our protocol can significantly reduce redundant traffic while keeping the delivery ratio at useful levels. In the second part we study the benefits of hiding the switching delay by using two switchable interfaces with the constraint that only one interface can transmit at a time.
Book Synopsis Efficient Broadcasting in Mobile Ad Hoc and Wireless Sensor Networks by :
Download or read book Efficient Broadcasting in Mobile Ad Hoc and Wireless Sensor Networks written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In mobile ad hoc networks (MANETs)[1], a mobile station (MS) can communicate with nodes outside of its transmission range by employing intermediate nodes as relays. To find a path to a specific destination node, the source node broadcasts route request packets that are forwarded to all other nodes. A simple flooding scheme is employed in AODV[2], where every node rebroadcasts these route request packets even if some of its neighbors have already broadcast the requests and thus the rebroadcasts may reach no additional nodes. In MANETs, broadcasting is extensively used in route discovery, address resolution, and many other network services. The efficiency of broadcasting protocol can dramatically affect the performance of the entire network. Appropriate use of a probabilistic method can reduce the number of rebroadcasting, therefore reduce the chance of contention and collision among neighboring nodes. A good probabilistic broadcast protocol can achieve higher throughput and lower energy consumption, without sacrificing reachability or having any significant degradation. In this research, we study the problem of using probabilistic approaches to improve broadcasting and route discovery performance in wireless ad hoc and sensor networks. Our contributions can be summarized as follows. First, we propose a selfish node based approach. In this approach, we categorize MSs into normal nodes and selfish nodes. Normal nodes forward packets for other nodes while selfish nodes do not. The advantage of using selfish nodes is that the total rebroadcast traffic can be reduced. The disadvantage is that we may miss the optimal route and suffer from a low delivery rate. In this approach, we use a probabilistic method to set up a proper number of selfish nodes. Using a combination of gossiping and dominating set, we can reduce the route discovery cost by minimizing the number of rebroadcasts, while achieving higher delivery rate due to the reduction of rebroadcast traffic, thereby reducing the number of collisions. Second, we propose a leveled probabilistic approach. In this approach, we use a pre-assigned probability model to avoid redundant packet relays. In our protocol, a MS probabilistically sends relay packets (rebroadcasts) according to its neighborhood information. Our approach categorizes MSs into four groups. For each group of nodes, we assign a specified value of rebroadcasting probability. The MSs with more neighbors are given higher rebroadcasting probability. Using this method, we can reduce routing cost by minimizing the number of rebroadcasts in route discovery phase without significantly affecting the network connectivity. Third, we propose a dynamic probabilistic approach. In this approach, we dynamically adjust the rebroadcasting probability as per the node distribution and node movement. This is conducted based on locally available information. In addition, our approach does not require any assistance from accurate distance measurements or exact location determination. This approach can further reduce routing cost by adapting its behavior according to the environment changes. Fourth, we compare MANETs and WSNs (wireless sensor networks). We realize the difference between MANETs and WSNs in terms of the node characteristics, energy consumption, mobility model and the traffic model. We also evaluate sensing coverage and communication coverage for different sensor range or communication range. Fifth, we propose a broadcasting scheme using connecting areas. We assign/select connecting areas during the network start up period. Only the connecting area head node located inside one of the connecting areas is responsible to rebroadcast the packet while the nodes outside the connecting areas do not rebroadcast. By choosing the size of the connecting area and the placement of the connecting areas, we can reduce the rebroadcasting cost while maintaining the reachability. Sixth, we propose a scheme that is based on redundant degree of each sensor. In this approach, we evaluate the redundant degree value of each sensor node and use this value to decide whether to rebroadcast packet or not. The rebroadcast from a node with high degree of redundancy has high possibility to be redundant. We set up a threshold to allow nodes with low enough degree connectivity to rebroadcast packets. In this work, we first describe the details of our protocols, comparing them with AODV and other protocols, and presenting evaluation results in MANETs. Analytical and simulation results show that our approaches outperform the AODV protocol on several metrics in most cases, including the average number of rebroadcasts, average number of packet collisions, end-to-end delay, and the throughput. We propose broadcasting protocols in wireless sensor networks, and explore other methods to further improve the performance of broadcasting and route discovery in MANETs and WSNs.
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Network Wide Broadcasting Protocols for Mobile Ad Hoc Networks by : Bradley B. Williams
Download or read book Network Wide Broadcasting Protocols for Mobile Ad Hoc Networks written by Bradley B. Williams and published by . This book was released on 2002 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Broadcast Protocols in Mobile Ad Hoc Networks by : Abdelmajid Khelil
Download or read book Broadcast Protocols in Mobile Ad Hoc Networks written by Abdelmajid Khelil and published by . This book was released on 2008-10-01 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of an Efficient Ad Hoc Broadcasting Scheme for Critical Networking Environments by : Ahmed Ghulam Mustafa Saber Karam
Download or read book Development of an Efficient Ad Hoc Broadcasting Scheme for Critical Networking Environments written by Ahmed Ghulam Mustafa Saber Karam and published by . This book was released on 2016 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile ad hoc network has been widely deployed in support of the communications in hostile environment without conventional networking infrastructure, especially in the environments with critical conditions such as emergency rescue activities in burning building or earth quick evacuation. However, most of the existing ad hoc based broadcasting schemes either rely on GPS location or topology information or angle-of-arrival (AoA) calculation or combination of some or all to achieve high reachability. Therefore, these broadcasting schemes cannot be directly used in critical environments such as battlefield, sensor networks and natural disasters due to lack of node location and topology information in such critical environments. This research work first begins by analyzing the broadcast coverage problem and node displacement form ideal locations problem in ad hoc networks using theoretical analysis. Then, this research work proposes an efficient broadcast relaying scheme, called Random Directional Broadcasting Relay (RDBR), which greatly reduces the number of retransmitting nodes and end-to-end delay while achieving high reachability. This is done by selecting a subset of neighboring nodes to relay the packet using directional antennas without relying on node location, network topology and complex angle-of-arrival (AoA) calculations. To further improve the performance of the RDBR scheme in complex environments with high node density, high node mobility and high traffic rate, an improved RDBR scheme is proposed. The improved RDBR scheme utilizes the concept of gaps between neighboring sectors to minimize the overlap between selected relaying nodes in high density environments. The concept of gaps greatly reduces both contention and collision and at the same time achieves high reachability. The performance of the proposed RDBR schemes has been evaluated by comparing them against flooding and Distance-based schemes. Simulation results show that both proposed RDBR schemes achieve high reachability while reducing the number of retransmitting nodes and end-to-end delay especially in high density environments. Furthermore, the improved RDBR scheme achieves better performance than RDBR in high density and high traffic environment in terms of reachability, end-to-end delay and the number of retransmitting nodes.
Book Synopsis Association of Asian Studies. Monographs and Papers by :
Download or read book Association of Asian Studies. Monographs and Papers written by and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of New Broadcast Protocols in a Mobile Ad Hoc Network Based on Machine Learning by : Fuat Bilgin
Download or read book Development of New Broadcast Protocols in a Mobile Ad Hoc Network Based on Machine Learning written by Fuat Bilgin and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cooperative Protocols in Dense Wireless Networks for Broadcast and Consensus by : Shrut Kirti
Download or read book Cooperative Protocols in Dense Wireless Networks for Broadcast and Consensus written by Shrut Kirti and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Network congestion is a communication bottleneck in large wireless networks which use packet-switched communications, impeding their performance in critical applications like network broadcast and in-network data processing. This forms the motivation for this thesis. We propose low complexity physical layer communication protocols that use cooperative transmission to ameliorate this problem. We show that cooperation at the physical layer can significantly improve performance with relatively small coordination overheads by exploiting the broadcast nature of the wireless channel. In the first part of the thesis, we address congestion in broadcast and propose decode and forward protocols that can accommodate multiple users broadcasting their content simultaneously. These protocols incorporate state of the art techniques like power control, successive interference cancellation, use of sideinformation for decoding, and interference alignment. By considering the two user linear network in depth we obtain the necessary conditions for the successful broadcast of the content of multiple users. It is shown that these physical layer cooperative protocols achieve lower broadcast latency than packet-switched flooding protocols and are suitable for broadcast in environments with fading. Additionally, we examine the performance of single user broadcast in the presence of decoding errors and show that the errors in its information flow need not be catastrophic. Supporting numerical results are included. In the second part of the thesis, we employ a similar approach and propose an efficient physical layer architecture for average consensus gossiping algorithms which perform in-network computation. This architecture relies on structured codes which combine channel and source coding. These codes result in consensus updates that are data driven, where transmissions are scheduled based on the states of the nodes rather than their index. Through this simple strategy we show that in spite of bandwidth and power limitations, nodes in an increasingly dense network can converge to the average with bounded delay and precision. Simulations show that this strategy outperforms packet-switched protocols even for moderately sized networks.
Book Synopsis Spectrum and Energy Efficient Medium Access Control for Wireless Ad Hoc Networks by : Kamal Rahimi Malekshan
Download or read book Spectrum and Energy Efficient Medium Access Control for Wireless Ad Hoc Networks written by Kamal Rahimi Malekshan and published by . This book was released on 2016 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasingly growing number of mobile devices and volume of mobile data traffic necessitate establishing an effective self-organizing wireless ad hoc network to efficiently utilize radio spectrum and energy. The transmissions time and bandwidth should be dynamically coordinated based on instantaneous traffic load of the links in the network. Energy consumption in a mobile device can be reduced by putting the radio interface into a sleep mode. However, the mobile device cannot receive incoming data packets in the sleep mode. Thus, awake and sleep times of radio interfaces should be carefully planned to avoid missing incoming packets. In a wireless network, links that are far apart in distance can simultaneously transmit using the same bandwidth without interfering reception at destination nodes. Concurrent transmissions should be properly scheduled to maximize spatial spectrum utilization. Also, the transmission power level of each link should be optimized to enhance spectrum and energy efficiencies. First, we present a new energy-efficient medium access control (MAC) scheme for a fully connected wireless ad hoc network. Energy consumption is reduced by periodically putting radio interfaces in the sleep mode and by reducing transmission collisions. The network throughput and average packet transmission delay are also improved because of lower collision and contention overhead. The proposed MAC scheme can achieve energy saving for realtime traffic which requires a low packet transmission delay. An analytical model is established to evaluate the performance of the proposed MAC scheme. Analytical and simulation results demonstrate that the proposed scheme has a significantly lower energy consumption, achieves higher throughput, and has a lower packet transmission delay in comparison with existing power saving MAC protocols. Second, we present a novel distributed MAC scheme based on dynamic space-reservation to effectively coordinate transmissions in a wireless ad hoc network. A set of coordinator nodes distributed over the network area are employed to collect and exchange local network information and to periodically schedule links for transmission in a distributed manner. For each scheduled transmission, a proper space area around the receiver node is reserved to enhance spatial spectrum reuse. Also, the data transmission times are deterministic to minimize idle-listening radio interface energy consumption. Simulation results demonstrate that the proposed scheme achieves substantially higher throughput and has significantly lower energy consumption in comparison with existing schemes. We study joint scheduling and transmission power control in a wireless ad hoc network. We analyze the asymptotic joint optimal scheduling and transmission power control, and determine the maximum spectrum and energy efficiencies in a wireless network. Based on the asymptotic analysis, we propose a novel scheduling and transmission power control scheme to approach the maximum spectrum efficiency, subject to an energy consumption constraint. Simulation results show that the proposed distributed scheme achieves 40% higher throughput than existing schemes. Indeed, the scheduling efficiency of our proposed scheme is about 70% of the asymptotic optimal scheduling and transmission power control. Also, the energy consumption of the proposed scheme is about 20% of the energy consumed using existing MAC protocols. The proposed MAC, scheduling and transmission power control schemes provide effective spectrum sharing and energy management for future wireless hotspot and peer-to-peer communication networks. The presented asymptotic analysis determines the maximum spectrum and energy efficiencies in a wireless network and provides an effective means to efficiently utilize spectrum and energy resources based on network traffic load and energy consumption constrains.
Book Synopsis Protocols for Multi-antenna Ad-hoc Wireless Networking in Interference Environments by : Danielle Ayodele Hinton
Download or read book Protocols for Multi-antenna Ad-hoc Wireless Networking in Interference Environments written by Danielle Ayodele Hinton and published by . This book was released on 2010 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fundamental question for the design of future wireless networks concerns the nature of spectrum management and the protocols that govern use of the spectrum. In the oligopoly model, spectrum is owned and centrally managed, and the protocols tend to reflect this centralized nature. In the common's model, spectrum is a public good, and protocols must support ad hoc communication. This work presents the design, tradeoffs and parameter optimization for a new protocol (Simultaneous Transmissions in Interference (STI-MAC)) for ad hoc wireless networks. The key idea behind the STI-MAC protocol is 'channel stuffing, ' that is, allowing network nodes to more efficiently use spatial, time and frequency degrees of freedom. This is achieved in three key ways. First, 'channel stuffing' is achieved through multiple antennas that are used at the receiver to mitigate interference using Minimum-Mean-Squared-Error (MMSE) receivers, allowing network nodes to transmit simultaneously in interference limited environments. The protocol also supports the use of multiple transmit antennas to beamform to the target receiver. Secondly, 'channel stuffing' is achieved through the use of a control channel that is orthogonal in time to the data channel, where nodes contend in order to participate on the data channel. And thirdly, 'channel stuffing' is achieved through a protest scheme that prevents data channel overloading. The STI-MAC protocol is analyzed via Monte-Carlo simulations in which transmitter nodes are uniformly distributed in a plane, each at a fixed distance from their target receiver; and as a function of network parameters including the number of transmit and receive antennas, the distance between a transmitter-receiver pair (link-length), the average number of transmitters whose received signal is stronger at a given receiver than its target transmitter (link-rank), number of transmitter-receiver pairs, the distribution on the requested rate, the offered load, and the transmit scheme. The STI-MAC protocol is benchmarked relative to simulations of the 802.11(n) (Wi-Fi) protocol. The key results of this work show a 3X gain in throughput relative to 802.11(n) in typical multi-antenna wireless networks that have 20 transmitter-receiver pairs, a link-length of 10 meters, four receive antennas and a single transmit antenna. We also show a reduction in delay by a factor of two when the networks are heavily loaded. We find that the link-rank is a key parameter affecting STIMAC gains over Wi-Fi. In simulations of networks with 40 transmit-receiver pairs, link-rank of three, a link-length of 10 meters, and eight transmit and receive antennas in which the transmitter beamforms to its target receiver in its strongest target channel mode, we find gains in throughput of at least 5X over the 802.11(n) protocol.
Download or read book Chinese Journal of Electronics written by and published by . This book was released on 2005 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An efficient reliable broadcast protocol for mobile ad-hoc networks by : Einar Vollset
Download or read book An efficient reliable broadcast protocol for mobile ad-hoc networks written by Einar Vollset and published by . This book was released on 2003 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Network Protocols for Ad-hoc Networks with Smart Antennas by : Karthikeyan Sundaresan
Download or read book Network Protocols for Ad-hoc Networks with Smart Antennas written by Karthikeyan Sundaresan and published by . This book was released on 2006 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: For heterogeneous smart antenna networks, we develop theoretical performance bounds by studying the impact of increasing degree of heterogeneity on network throughput performance. Given that the antenna technologies are already unified in the network, unified solutions are not required. However, we do develop efficient MAC and routing protocols to best leverage the available heterogeneous capabilities present in the network. We also design efficient cooperation strategies that will further help the communication protocols in exploiting the available heterogeneous capabilities in the network to the best possible extent.
Book Synopsis Efficient Broadcast in Mobile Ad Hoc Networks Utilizing Rateless Coding by : Jason Douglas Pitts
Download or read book Efficient Broadcast in Mobile Ad Hoc Networks Utilizing Rateless Coding written by Jason Douglas Pitts and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
