Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 5 Articles
To reduce the energy cost of underwater acoustic sensor networks (UWSNs), the duty cycle (i.e., periodic wake-up\nand sleep) concept has been used in several medium access control (MAC) protocols. Although these\nprotocols are energy efficient, they sacrifice bandwidth utilization, which leads to lower transmission rate. In\norder to solve this problem, asynchronous duty cycle with network-coding Asynchronous Duty Cycle with\nNetwork-Coding MAC (ADCNC-MAC) is proposed. It contains initialization of the MAC protocol phase and\ndata transmission phase. In the first phase, we use an asynchronous duty cycle to find a rendezvous time\nfor exchanging data. A strategy to select network coder nodes is presented to confirm the number of network\ncoder nodes and distribution in the network coder layer. In the data transmission phase, the network coder nodes\ntransmit using the proposed network-coding-based algorithm and a higher volume of packet will be transmitted to\nthe Sink with the same number of transmissions. Simulation results show that ADCNC-MAC achieves higher power\nefficiency, improves packet delivery ratio (PDR), and network throughput....
Vehicular networks are a cornerstone of the envisioned intelligent transportation system (ITS) by enabling vehicles to\ncommunicate with each other via vehicle-to-vehicle (V2V) communications to overcome the current and future needs\nfor increasing traffic safety and efficiency. In this paper, we employ the knapsack problem (KP) to formulate the\nproblem of cooperative scheduling and radio resource management in vehicular networks for non-real time services.\nFor the sake of maximizing sum utility (MSU) of the networks, we propose two-dimensional-multi-choice knapsack\nproblem (2D-MCKP)-based scheduling scheme to select the coordinator vehicles for the sink vehicle and allocate\nradio resource to V2V and vehicle-to-infrastructure (V2I) links to solve the MSU optimization problem. Simulation\nresults indicate that the proposed scheme significantly improves the average utility and average data rates with\nsustainable computational complexity. Moreover, the designed cooperative communication system achieves higher\nspectral efficiency and better fairness....
In this paper, we face the implementation of a non-linear kernel method for regression on a wireless sensor network\n(WSN) based on MICAz motes. The operating system used is TinyOS 2.1.1. The algorithm estimates the value of some\nmagnitude from the measurements of the motes in a distributed approach where information and computations are\nperformed asynchronously. This proposal includes a research on the potential problems encountered along with the\ndeveloped solutions. Namely, matrix and floating computations, acknowledgement mechanisms and data loss....
Due to rapid developments in mobile technology as well as various multimedia features like messaging, browsing,\nand streaming, user-created mobile contents are increasing, both in terms of quantity and quality, and at the same\ntime are shared in real time. To get into step with such movements, new content-centric networking (CCN) has\nappeared. However, CCN has not taken the effect of consumer device movements into consideration. So, this paper\nproposes a partial path extension scheme to provide lower communication overhead, shorter download time, and\nlower network resource consumption in mobile consumer environments....
In real-time multimedia applications, the most problems are how to store, process, and transport the multimedia\ndata with cloud, how to optimize the cloud platform to satisfy the user demand, as well as how to provide the\nquality of service (QoS) guarantees by combining cloud platform and wireless sensor networks (WSNs). To overcome\nthese issues, the multimedia cloud was designed according to the characteristics of group of pictures (GOP), determining\ndegree, and video frame density. The opportunistic dynamic multimedia cloud platform was proposed on the basis of\nthe variation of packet error rate, decodable frame ratio and peak signal-to-noise ratio (PSNR) with channel quality. Then,\nthe optimal multi-relay hierarchical cooperative multimedia transmission scheme was designed and implemented by\nreconstructing the cooperative multimedia stream based on the framing of GOP. For enhancing the multimedia cloud\ncomputing efficiency and decreasing the complexity of encoding and decoding of multimedia stream, we combined\nthe opportunistic dynamic multimedia cloud platform and cooperative multimedia stream, which can also enhance the\nresources utilization of WSNs. Finally, the QoS guarantee protocol with the combination of opportunistic dynamic\nmultimedia cloud platform and cooperative multimedia stream for WSNs (ODM-CM-WSN) was presented. Especially,\nthe layered architectural model for multimedia applications and the opportunistic cooperative multimedia cloud service\nmodel were developed. The mathematical and simulation results demonstrate that the proposed QoS guarantee\nprotocol can satisfy the various requirements of multimedia applications and provide reliable and efficient cloud\nservices with WSNs....
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