Learn More
Wireless sensor networks are often battery-powered, and hence extending the network lifetime is one of the primary concerns in the ubiquitous deployment of wireless sensor networks. One approach to efficiently utilize the limited energy supplies of the sensors is to have the medium access control (MAC) protocol duty-cycle the sensors, periodically putting(More)
SMAC is a popular duty-cycled MAC protocol, designed for wireless sensor networks to save energy and prolong the network lifetime. However, existing work evaluates the performance of SMAC solely through simulations or field measurements. To the best of our knowledge, there are no analytical models for evaluating the performance of SMAC. In this paper, we(More)
— IEEE 802.16 networks are going to provide broadband wireless access with quality of service (QoS) guarantee. In all of services, real-time video traffic plays an impeditive role because of its varying bit-rate and stringent delay constraint. To the best of our knowledge, no call admission control (CAC) and scheduling schemes cover throughput expectation,(More)
IEEE fixed 802.16 network aims at providing broadband wireless access with quality of service (QoS) guarantee. In all its services, real-time video traffic plays an impedi-tive role because of its varying bit-rate. In this paper, by taking advantage of traffic characteristics, a new scheduling and call admission control (CAC) scheme for real-time video(More)
Goals Conduct theoretical and lab-experimental investigations of a control problem of a spacecraft rendezvous with a non-cooperative satellite in order to capture it in an optimal manner. The optimum can be in the sense of minimum time, minimum fuel consumption, or a rationale combination of both. Motivation: There is a growing interest in autonomously(More)
In this paper we propose a new routing protocol for mobile wireless sensor networks, which fixed and mobile sensor nodes in the same network, called Energy-efficient Chain-cluster Routing protocol (ECRM). The protocol organizes the fixed node, whose battery is impossible to be recharged, into the communication backbone to maintain the basic connectivity of(More)
Various applications of wireless sensor networks require multihop data transmission over error-prone wireless links, hence multipath routing can be used to meet the application's reliability requirement. On the other hand, wireless sensors are usually battery powered, and thus it is very important to save energy in order to prolong the network lifetime. In(More)
Sensor sleeping is a widely-used and cost-effective technique to save energy in wireless sensor networks. Protocols at different stack levels can, either individually or simultaneously, make the sensor sleep so as to extend the application lifetime. To determine the best choice for sensor sleeping under different network conditions and application(More)
—In wireless sensor networks, multipath routing is used to alleviate reliability degradation due to multihop transmissions over error-prone wireless channels. However, multipath routing is not energy-efficient, as it requires all the nodes in the network to always be awake. To prolong the network lifetime while maintaining a certain reliability performance,(More)
Utilizing the nonsubsampled contour let transform's(NSCT)advantages of translation invariance", "multi-resolution", "multidirection", "A image de-noising algorithm using adaptive bayes threshold by sub band based on nonsubsampled contour let transform is presented. Source images are decomposed to the domain of the NSCT, and According to different scales,(More)