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Optimization of wireless smart metering systems requires an entirely different approach compared to traditional communication networks. For devices operating without external power supply energy efficiency is a key factor, because it will determine the duration of operation time without external intervention. The data packets are less sensitive for delay, hence it is possible to wait for more measurement...
In wireless smart metering optimization for energy efficiency is indispensable, because in case of systems without external power supply, battery life is a key factor regarding the usability of the whole system. Sensor networks are less sensitive for delay, this is why aggregation of packets is possible. The aim of this paper is to determine analytically the amount of meter records to aggregate in...
Cooperative relay techniques are exploited to reduce the transmission energy consumption which is very important for average and long range transmission in wireless sensor networks (WSNs). In this paper, the system having a two-antenna source, two one-antenna relays and a one-antenna destination is considered. Using distributed space-time code at relays, MIMO simple cooperative relay model (MSCR)...
The design, manufacture and deployment of embedded systems become increasingly complex and multidisciplinary process. Before the steps of manufacturing and deployment, a simulation and validation phase is necessary. Given the increasing complexity of systems, a specific simulation and validation process must take place. This simulation ideally made in a single development environment, should cover...
Adaptive packet sizing techniques are widely used in wireless communication to enhance the link reliability. Typically, shorter packets are less error prone than longer packets. Adaptive packet size technique is used in IEEE 802.11 wireless network to enhance link reliability and packet delivery ratio. In this work, we adopt this technique to work in IEEE 802.15.4 based networks, and specifically...
We propose an efficient cooperative ARQ (Automatic Repeat reQuest) scheme for underwater acoustic communications, in which cooperative nodes are used to provide more reliable alternative paths for a specific source-to-destination connection. Based on the knowledge of inter-node distances, a cooperative region is defined to include all possible candidates for cooperative nodes from a given pair of...
In wireless systems where half duplex transceivers are employed, most existing practical cooperative protocols achieve a spectral efficiency of 0.5 symbols per channel use (pcu). Recently a decode-and-forward protocol was developed to achieve a spectral efficiency of 2/3 symbols pcu. But there is no practical amplify-and-forward (AF) protocol that can achieve a spectral efficiency higher than 0.5...
This paper presents a performance evaluation of wireless sensor networks (WSN) based on impulse radio ultra wideband (IR-UWB) over a new simulation platform developed for this purpose. The simulation platform is built on an existing network simulator: global mobile information system simulator (GloMoSim). It mainly focuses on the accurately modeling of IR-UWB physical (PHY) and medium access control...
In this paper, we review some of the prominent gains achieved with cooperative communications, a new way of communications, which has found its applications in almost every wireless network, from cellular to sensor networks. Cooperative communications is a way of transmission, where wireless users not only transmit their own information, but also repeat other users' information during its transmission...
Underwater communications is a very challenging topic due to its singular channel characteristics. Most protocols used in terrestrial wireless communications can not be directly applied in the underwater world. A high bit error rate and low propagation delay make the design of reliable transport protocols especially awkward. In this paper, we first propose four schemes that combine forward error correction...
In this paper, we provide a saturation throughput analysis of the IEEE 802.11 protocol at the data link layer by including the impact of both transmission channel and capture effects in Rayleigh fading environment. Impacts of both non-ideal channel and capture effects, specially in an environment of high interference, become important in terms of the actual observed throughput. As far as the 4-way...
Three applications in wireless networks where model-free stochastic learning is applicable, are discussed. The learning based optimization problems are formulated and simulation results are presented. Some open issues are also discussed.
In this paper, we propose a cross-layer optimization approach that exploits retransmission diversity in wireless CDMA communications. Conventionally, data packets that are not correctly detected are usually dropped. These dropped packets can be used to help data packet detection. By exploiting all the retransmitted packets, data packets can be correctly detected with higher probability. The proposed...
This paper explores the attributes, layering models and objective functions in cross layer designs for mobile ad hoc wireless networks by taking all the statistical characteristics and constraints from the physical (PHY) layer, media access control (MAC) layer and network (NET) layer into consideration. This paper reviews the entire network optimization across all the PHY/MAC/NET layers. At the PHY...
Wireless sensor networks consist of a large number sensors spread across a given geographical area. Each sensor has its own communication capability as well as certain level of intelligence for signal processing and networking. As the sensor nodes are densely populated, communication range requirement for these nodes is smaller. After signal detection, a number of sensor nodes communicate over the...
Due to resource constraints, digital image transmissions are a significant challenge for image sensor based wireless sensor networks (WSN). In this paper, we propose a novel robust and energy-efficient scheme, called image component transmission (ICT) in WSN by providing various levels of reliability during image transmissions. Essential components such as the information for the positions of significant...
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