Node Degree based Improved Hop Count Weighted Centroid Localization Algorithm

Hop-count based weighted centroid localization is a simple and straightforward localization algorithm, which uses anchors with known positions and the hop count to these anchors to estimate the real position of nodes. Especially in sensor networks, where energy restrictions prevent more complex algorithms, this fast and simple algorithm can be used. Unfortunately the localization error of the algorithm can hinder the practical usage. In this paper we will improve the weighted centroid algorithm for hop count based localization by adding the node degree on the paths to the referenced anchors into the weights. After an analysis to obtain theoretically optimal coefficients we will show by means of simulation that for longer hop counts to the anchors and areas with different node degrees the proposed ND-WCL algorithm outperforms the known hop count based weighted centroid localization algorithm

Theory that Matters! Problem-based learning towards 5G Communication System and Standards

Theory that Matters! Problem-based learning towards 5G Communication System and Standard

A Two Layer Guaranteed and Sustained Rate Based Scheduler for IEEE 802.16-2009 Based WiMAX Networks

Part 4: Protocols and PerformanceInternational audienceWorldwide Interoperability for Microwave Access (WiMAX) based on the IEEE 802.16-2009 standard is a serious competitor of Long Term Evolution (LTE) for cellular networks providing high data rates to mobile users. To support various multimedia applications the Quality of Service (QoS) support is a crucial function. While the IEEE 802.16- 2009 standard defines five service classes to support the QoS requirements of various multimedia applications, the algorithms and especially the scheduling algorithms to enforce these requirements have not been specified for vendor differentiation. We propose a scheduling algorithm allocating resources according to the guaranteed and sustained rates of each connection, in contrast to common two layer scheduling approaches differentiating between service classes. Simulation results show that our scheduler is able to fulfill the QoS requirements of connections defined by the IEEE 802.16 standard