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Volume 16 No. 6
20 June 2011

2011, 16(6): 561-568.   doi:10.1016/S1007-0214(11)70075-X
Abstract ( 104 )  ( 55 )   Save
One of the fundamental design challenges in designing a Wireless Sensor Network (WSN) is to maximize the network lifetime, as each sensor node of the network is equipped with a limited power battery. To overcome this challenge, different methods were developed in the last few years using such techniques as network protocols, data fusion algorithms using low power, energy efficient routing, and locating optimal sink position. This paper focuses on finding the optimal sink position. Relay nodes ar...

2011, 16(6): 569-575.   doi:10.1016/S1007-0214(11)70076-1
Abstract ( 122 )  ( 70 )   Save
This paper describes an optimal power allocation scheme for orthogonal frequency division multiple access two-way relay networks with physical network coding. The aim is to enhance the achievable sum rate of the terminals for a constrained total transmit power. Convex optimization is used to derive a closed-form solution for the power allocation between the relay node and the two terminals. This reduces the variable dimensionality of the objective function for the power assignment problem among ...

2011, 16(6): 576-582.   doi:10.1016/S1007-0214(11)70077-3
Abstract ( 170 )  ( 65 )   Save
Current highway tunnel lighting control systems are often manually controlled, resulting in significant energy waste. This article designs a fuzzy control algorithm for tunnel lighting energy control systems. The system uses LED (Light Emitting Diode) lighting, so the fuzzy control algorithm is designed for LED lights. The traffic and the natural illumination level are used as parameters in the intelligent lighting control algorithm. This system has been deployed in the Lengshui tunnel on the 49...

2011, 16(6): 583-588.   doi:10.1016/S1007-0214(11)70078-5
Abstract ( 151 )  ( 49 )   Save
Most current Global System for Mobile Communications (GSM) frequency planning methods evaluate the interference and assign frequencies based on measurement reports. Assigning the same or adjacent frequencies to cells close to each other will introduce co-channel and adjacent channel interference which will reduce network performance. Traditionally, man power is used to check and allocate new frequencies which is time consuming and the accuracy is not satisfactory. This paper presents an intellig...

2011, 16(6): 589-600.   doi:10.1016/S1007-0214(11)70079-7
Abstract ( 137 )  ( 25 )   Save
A large proportion of Internet of Things (IoT) applications are internally publish/subscribe in nature, and traditional architecture cannot support them efficiently and flexibly. In essence, supporting efficient publish/subscribe systems requires data-oriented naming and efficient multicast. Since deployment of native IP-based multicast has failed, overlay-based multicast has become the practical choice. Since load balancing between heterogeneous nodes is an important issue, designing an optimal...

2011, 16(6): 601-610.   doi:10.1016/S1007-0214(11)70080-3
Abstract ( 159 )  ( 25 )   Save
The powerful processors and the variety of sensors in new and upcoming mobile Internet devices, such as iPhones and Android-based smart phones, can be leveraged to build cyber-physical applications that collect sensor data from the real world and communicate it back to the Internet for comprehensive processing. Available bandwidth measurement has been discussed previously in the computer networking community. Currently, it is important for cyber-physical applications to behave smartly since thes...

2011, 16(6): 611-621.   doi:10.1016/S1007-0214(11)70081-5
Abstract ( 162 )  ( 74 )   Save
In recent years, underwater acoustic wireless sensor networks have been used in many areas. There have been many field trials of acoustic propagation models and statistics for shallow water conditions. However, field trials are limited environmentally and, hence, not widely accepted. Simulations of the impulse response of a shallow underwater acoustic channel allows less expensive system tests that are reproducable. This paper presents a shallow water acoustic channel model based on the actual a...

2011, 16(6): 622-631.   doi:10.1016/S1007-0214(11)70082-7
Abstract ( 181 )  ( 43 )   Save
The coverability of Wireless Sensor Networks (WSNs) is essentially a Quality of Service (QoS) problem that measures how well the monitored area is covered by one or more sensor nodes. The coverability of WSNs was examined by combining existing computational geometry techniques such as the Voronoi diagram and Delaunay triangulation with graph theoretical algorithmic techniques. Three new evaluation algorithms, known as CRM (Comprehensive Risk Minimization), TWS (Threshold Weight Shortest path), a...

2011, 16(6): 632-639.   doi:10.1016/S1007-0214(11)70083-9
Abstract ( 192 )  ( 38 )   Save
The Clapping and Broadcasting Synchronization (CBS) algorithm, which is specifically designed for large-scale sensor networks with low communication overhead and high synchronization accuracy, is introduced. The CBS protocol uses broadcasting rather than pairwise communication to accomplish synchronization. In the CBS scheme, the initial offset of local clocks can be successfully eliminated by the operation of clapping nodes, which leads to significant improvement in synchronization accuracy. Th...

2011, 16(6): 640-647.   doi:10.1016/S1007-0214(11)70084-0
Abstract ( 108 )  ( 64 )   Save
Smart grid is envisioned as a critical application of cyber-physical systems and of the internet of things. In the smart grid, smart meters equipped with wireless sensors can upload meter readings (data) to smart grid control and schedule centers via the advanced metering infrastructure to improve power delivery efficiency. However, data gathered in short intervals, such as 15 minutes, will expose customers' detailed daily activities (for example, when they get up and when they use oven) using n...

2011, 16(6): 648-656.   doi:10.1016/S1007-0214(11)70085-2
Abstract ( 95 )  ( 39 )   Save
Navigation with sensor networks has shown many advantages and great potential in many scenarios. Previous works have mainly focused on selecting the shortest path to navigate an internal user out of an emergency field. However, they did not consider variations of the dangerous areas which usually occur in practical applications. This paper presents an efficient dynamic routing algorithm to successfully guide users to the destination exit. The navigation goal is looking for a safe and short path ...

2011, 16(6): 657-668.   doi:10.1016/S1007-0214(11)70086-4
Abstract ( 128 )  ( 27 )   Save
Emergency navigation with a large number of sensors can serve as a safety service in emergencies. Recent studies have focused on navigation protocols to safely guide people to exits while helping them avoid hazardous areas. However, those approaches are not applicable in all circumstances. Both the dynamics of the environment and the mobility of users are key challenges for the efficiency and effectiveness of navigation protocols. The concepts of navigability and reachability are used to evaluat...