Regenerative and Adaptive schemes Based on Network Coding for Wireless Relay Network

Recent technological advances in wireless communications offer new opportunities and challenges for relay network.To enhance system performance, Demodulate-Network Coding (Dm-NC) scheme has been examined at relay node; it works directly to De-map the received signals and after that forward the mixture to the destination. Simulation analysis has been proven that the performance of Dm-NC has superiority over analog-NC. In addition, the Quantize-Decode-NC scheme (QDF-NC) has been introduced. The presented simulation results clearly provide that the QDF-NC perform better than analog-NC. The toggle between analogNC and QDF-NC is simulated in order to investigate delay and power consumption reduction at relay node.Comment: 11 pages, 8 figures, International Journal of Computer Networks & Communications (IJCNC), Vol.4, No.3, May 201

Adaptive multi-channel MAC protocol for dense VANET with directional antennas

Directional antennas in Ad hoc networks offer more benefits than the traditional antennas with omni-directional mode. With directional antennas, it can increase the spatial reuse of the wireless channel. A higher gain of directional antennas makes terminals a further transmission range and fewer hops to the destination. This paper presents the design, implementation and simulation results of a multi-channel Medium Access Control (MAC) protocols for dense Vehicular Ad hoc Networks using directional antennas with local beam tables. Numeric results show that our protocol performs better than the existing multichannel protocols in vehicular environment

Relay selection for multiple access relay channel with decode-forward and analog network coding

This paper presents a relay selection for decode-and-forward based on network coding (DF-NC) and analog-NC protocols in general scheme of cellular network system. In the propose scheme the two source node simultaneously transmit their own information to all the relays as well as the destination node, and then, a single relay i.e. best with a minimum symbol error rate (SER) will be selected to forward the new version of the received signal. Simulation results show that, the DF-NC scheme with considerable performance has exactness over analog-NC scheme. To improve the system performance, optimal power allocation between the two sources and the best relay is determined based on the asymptotic SER. By increasing the number of relays node, the optimum power allocation achieve better performance than asymptotic SER.Comment: 11 pages, 5 figures; International Journal of Distributed and Parallel Systems (IJDPS) Vol.3, No.2, March 201

Understanding Social Characteristic from Spatial Proximity in Mobile Social Network

Over the past decades, cities as gathering places of millions of people rapidly evolved in all aspects of population, society, and environments. As one recent trend, location-based social networking applications on mobile devices are becoming increasingly popular. Such mobile devices also become data repositories of massive human activities. Compared with sensing applications in traditional sensor network, Social sensing application in mobile social network, as in which all individuals are regarded as numerous sensors, would result in the fusion of mobile, social and sensor data. In particular, it has been observed that the fusion of these data can be a very powerful tool for series mining purposes. A clear knowledge about the interaction between individual mobility and social networks is essential for improving the existing individual activity model in this paper. We first propose a new measurement called geographic community for clustering spatial proximity in mobile social networks. A novel approach for detecting these geographic communities in mobile social networks has been proposed. Through developing a spatial proximity matrix, an improved symmetric nonnegative matrix factorization method (SNMF) is used to detect geographic communities in mobile social networks. By a real dataset containing thousands of mobile phone users in a provincial capital of China, the correlation between geographic community and common social properties of users have been tested. While exploring shared individual movement patterns, we propose a hybrid approach that utilizes spatial proximity and social proximity of individuals for mining network structure in mobile social networks. Several experimental results have been shown to verify the feasibility of this proposed hybrid approach based on the MIT dataset

Distributed Asynchronous Game Theoretic Solutions for Precoding Strategies in Multiuser MIMO Systems

ABSTRACT In this paper, we proposed and illustrated a distributed low-complex algorithm for precoding strategy selection in a multi-user Multiple-input Multiple-output (MU-MIMO) wireless system using noncooperative games. We formulate the game as a non-cooperative game for an asynchronous distributed system in multi-user MIMO system known as Partially asynchronous distributed algorithm (PADA) and the convergence (Nash Equilibrium (NE) point) of the game. Mathematical framework providing sufficient conditions guaranteeing the uniqueness of the NE and the convergence of the proposed algorithm is presented. (NE) which possess at least one pure strategy Nash equilibrium (NE) and the optimal strategy profile which maximizes the sum rate provides the solution for the existence and uniqueness of the game. The main focus is on non-cooperation of interference multi-user MIMO channel. Analysis of the proposed partially asynchronous distributed low-complex algorithm for precoding strategy selection in a multi-user MIMO wireless system using non-cooperative games is illustrated

COSR: A Reputation-Based Secure Route Protocol in MANET

<p/> <p>Now, the route protocols defined in the Mobile Ad Hoc Network (MANET) are constructed in a common assumption which all nodes contained in such networks are trustworthy and cooperative. Once malicious or selfish nodes exist, all route paths built by these protocols must be broken immediately. According to the secure problems within MANET, this paper proposes Cooperative On-demand Secure Route (COSR), a novel secure source route protocol, against malicious and selfish behaviors. COSR measures node reputation (NR) and route reputation (RR) by contribution, Capability of Forwarding (CoF) and recommendation upon Dynamic Source Route (DSR) and uses RR to balance load to avoid hotpoint. Furthermore, COSR defines path collection algorithm by NR to enhance efficiency of protocol. At last, we verify COSR through GloMoSim. Results show that COSR is secure and stable.</p