Cooperative Medium Access Control Protocol Design in Distributed Wireless Network PDF Download

Author: 鐘國峰
Publisher:
ISBN:
Category :
Languages : en
Pages : 134

View

Book Description

Author: Wei Song
Publisher: Springer
ISBN: 3319477269
Category : Technology & Engineering
Languages : en
Pages : 135

View

Book Description
This book focuses on the design and analysis of protocols for cooperative wireless networks, especially at the medium access control (MAC) layer and for crosslayer design between the MAC layer and the physical layer. It highlights two main points that are often neglected in other books: energy-efficiency and spatial random distribution of wireless devices. Effective methods in stochastic geometry for the design and analysis of wireless networks are also explored. After providing a comprehensive review of existing studies in the literature, the authors point out the challenges that are worth further investigation. Then, they introduce several novel solutions for cooperative wireless network protocols that reduce energy consumption and address spatial random distribution of wireless nodes. For each solution, the book offers a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate the analysis and examine the performance under various conditions. The last section of this book reveals several potential directions for the research on cooperative wireless networks that deserve future exploration. Researchers, professionals, engineers, and consultants in wireless communication and mobile networks will find this book valuable. It is also helpful for technical staff in mobile network operations, wireless equipment manufacturers, wireless communication standardization bodies, and governmental regulation agencies.

Author: Angelos Antonopoulos
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

View

Book Description
The introduction of third generation (3G) technologies has caused a vast proliferation of wireless devices and networks, generating an increasing demand for high level Quality of Service (QoS). The wide spread of mobile applications has further reinforced the user need for communication, motivating at the same time the concepts of user cooperation and data dissemination. However, this trend towards continuous exchange of information and ubiquitous connectivity is inherently restricted by the energy-greedy functionalities of high-end devices. These limitations, along with the pressure exerted on the Information and Communications Technology (ICT) industry towards energy awareness, have induced the design of novel energy efficient schemes and algorithms. In this context, the Medium Access Control (MAC) layer plays a key role, since it is mainly responsible for the channel access regulation, the transmission scheduling and the resource allocation, thus constituting an appropriate point to effectively address energy efficiency issues that arise due to the users overcrowding. This dissertation provides a contribution to the design, analysis and evaluation of novel MAC protocols for cooperative wireless networks. In our attempt to design energy efficient MAC schemes, we were extensively assisted by the introduction of new techniques, such as Network Coding (NC), that intrinsically bring considerable gains in system performance. The main thesis contributions are divided into two parts. The first part presents NCCARQ, a novel NC-aided Cooperative Automatic Repeat reQuest (ARQ) MAC protocol for wireless networks. NCCARQ introduces a new access paradigm for cooperative ARQ schemes, exploiting NC benefits in bidirectional communication among wireless users. The NCCARQ performance in terms of QoS and energy efficiency is assessed by means of analytical probabilistic models and extensive computer-based simulations, revealing the significant gains we can achieve compared to standardized MAC solutions. In addition, the impact of realistic wireless channel conditions on the MAC protocol operation further motivated us to study the NCCARQ performance in wireless links affected by correlated shadowing, showing that the channel correlation may adversely affect the distributed cooperation benefits. The second part of the thesis is dedicated to the investigation of MAC issues in wireless data dissemination scenarios. In particular, the existence of multiple source nodes in such scenarios generates conflicting situations, considering the selfish behavior of the wireless devices that want to maximize their battery lifetime. Bearing in mind the energy efficiency importance, we propose game theoretic medium access strategies, applying energy-based utility functions which inherently imply energy awareness. In addition, Random Linear NC (RLNC) techniques are adopted to eliminate the need of exchanging excessive control packets, while Analog NC (ANC) is employed to efface the impact of collisions throughout the communication. During the elaboration of this thesis, two general key conclusions have been extracted. First, there is a fundamental requirement for implementation of new MAC protocols in order to effectively deal with state-of-the-art techniques (e.g., NC), recently introduced to enhance both the performance and the energy efficiency of the network. Second, we highlight the importance of designing novel energy efficient MAC protocols, taking into account that traditional approaches - designed mainly to assist the collision avoidance in wireless networks - tend to be obsolete.

Author: Sithembiso G. Gama
Publisher:
ISBN:
Category : Code division multiple access
Languages : en
Pages : 174

View

Book Description

Author: Peijian Ju
Publisher:
ISBN:
Category : Telecommunications Relay Service
Languages : en
Pages : 0

View

Book Description
In the past decade, cooperative wireless networks have emerged as a promising technology that allows wireless devices to take advantage of diversity and link adaptation. In this thesis, we focus on the design and analysis of the medium access control (MAC) layer for the cooperative wireless networks, aiming at two main issues in this field: relay selection under mobility and incentive-based allocation for relaying packets. Specifically, we proposed and analysed 1) an intelligent cooperative MAC protocol to select stable helpers to provide better throughput; 2) two coordination schemes for multiple helpers to tradeoff the diversity advantage and transmission delay; 3) a moneyless incentive scheme which can stimulate the agreement of cooperation; and 4) three monetary incentive allocation mechanisms to stimulate cooperative relaying while maintaining the desired properties. Firstly, our proposed cooperative MAC protocol, referred as PTCoopMAC, can make use of the out-of-date information from the overheard signals to select the optimal stable helper to improve the system throughput. Secondly, we analysed the unconditional relaying success probability for a wireless diversity system with multiple random moving helpers. One Aloha-based and one timer-based coordination schemes were designed to balance the success probability and transmission delay. Thirdly, the moneyless incentive scheme for one cooperative pair transmission can tune up and down the channel access probability of the helper and the source as the reward and payment, respectively. We further provided the conditions on how to select the tuning factors to reach the cooperation agreement. Finally, we proposed three monetary incentive allocation mechanisms towards different design goals. The Vickrey-Clarke-Groves (VCG)-based mechanism aims at efficiency in social welfare; the probabilistic entrance auction (PEA) mechanism targets at lowering the computational effort; and the randomized (RND) mechanism attempts to strike a balance between the two mechanisms. All the proposed solutions were extensively evaluated by simulations. The results demonstrated that our solutions successfully addressed the challenges posed by user mobility and incentive for the cooperative wireless networks. The quality of service (QoS) can be significantly improved by properly incorporating cooperation among user devices.

Author: Md. Rajibul Islam
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Cooperative diversity is proposed to combat the detrimental effects of channel fading. In this thesis, we investigate the effectiveness of cooperative diversity in interference limited ad hoc networks. The throughput performance of ad hoc networks that employ cooperative diversity techniques is examined. The negative effects of relay transmission blocking and extra time delay due to using the relay node, on the network throughput are investigated. We show that cooperative diversity based ad hoc networks inherits relay blocking problem which causes net network throughput degradation. To solve the relay blocking problem, we propose a new cooperative medium-access-control (MAC) protocol where each relay is equipped with directive antennas and the transmitter-relay-receiver transmission mode is designed using two frequency channels. Furthermore, we discuss the throughput performance considering single and multiple relay scenarios and analyze the effect of interference on the throughput. Then we investigate the throughput performance of the proposed cooperative MAC protocol in the presence of position estimation errors. In the literature, a perfect position estimation of all nodes is commonly assumed. Here, we focus on the throughput performance of the cooperative network when taking into consideration the effect of directional-of-arrival (DOA) error caused by imperfect global-positioning system (GPS) position estimation. Our results show that using adaptive antennas at the relay becomes advantageous when the DOA error is less than 20 degrees. We noted that increasing the number of antennas (at the relay station) can improve the throughput performance but, on the other hand, the effect of node position error becomes more substantial.

Author: Lakshmi Narasimhan Kannan
Publisher:
ISBN:
Category : Ad hoc networks (Computer networks)
Languages : en
Pages : 468

View

Book Description
Wireless transmission medium suffers from channel impairments like fading and path loss leading to performance degradations in terms of reduced throughput and increased latency. Medium access control protocols designed for wireless networking today provide multiple retransmissions as a way to account for frame losses caused by the channel. By retransmitting in the same channel, effectiveness of retransmissions can be reduced due to prolonged periods of channel impairments like obstacles in the line of sight of communication. Spatial diversity provides statistically different channels that can compensate for frame losses. Wireless medium being broadcast in nature paves way to achieve spatial diversity by asking neighboring nodes that can overhear transmissions to retransmit the frames. This procedure is termed cooperation. The nodes that help in successful communication between two other nodes are called relays. Medium access control protocols that are designed to account for cooperation are called cooperative medium access control protocols. This thesis presents one such cooperative protocol. The cooperative protocol presented in this thesis is unique in that the relays are opportunistic in nature. Relays here only help the source that is transmitting frames to a destination when a transmission failure occurs. A metric to find a suitable relay is presented and heurisitic algorithms to find transmission rate pairs for links in the cooperative setup are also presented. The thesis also shows that the cooperative protocol proposed can also be used in multi-hop networks. A cross layer routing metric to jointly perform route and relay selection in multi-hop networks is also presented. Simulation and analytical studies were carried out and results are presented in this thesis comparing the performance of the cooperative protocol presented here and the standard protocol it is based on. Performance improvements in terms of throughput and latency are brought about by using opportunistic cooperation. The performance improvements depend on careful selection of relays and transmission rates used for the links in the cooperative setup. The gains perceived in single hop networks were also seen in multi-hop networks but the magnitude of gains in multi-hop scenarios were dependent on network topology.

Author: Jesús Alonso Zárate
Publisher:
ISBN: 9788469447994
Category :
Languages : en
Pages :

View

Book Description

Author: Alphan Ulusoy
Publisher: LAP Lambert Academic Publishing
ISBN: 9783843373999
Category :
Languages : en
Pages : 92

View

Book Description
Owing to their distributed architecture, networked control systems are proven to be feasible in scenarios where a spatially distributed control system is required. However, basic networked control systems cannot operate over general purpose wireless networks since the stability of the system is compromised due to unbounded delays and unpredictable packet losses that are typical in the wireless medium. Approaching the wireless networked control problem from two perspectives, this book introduces a novel wireless networked control system and a realistic cooperative medium access control protocol implementation that work jointly to achieve decent control even under unbounded delay, bursts of packet loss and ambient wireless traffic. The proposed system is implemented and thoroughly evaluated on a dedicated test platform under numerous scenarios and is shown to be operational under bursts of packet loss and ambient wireless traffic levels which are intolerable for basic networked control systems. The methods covered in this book should assist in developing various wireless networked control systems and should be especially useful to practicing control engineers.

Author: Kezhu Hong
Publisher:
ISBN:
Category : Computer network protocols
Languages : en
Pages : 286

View

Book Description