ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / As cost and power consumption of wireless devices decreases, it becomes increasingly practical to use wireless communications and control in residential settings. These networks share some of the same challenges and constraints as conventional telemetry networks. This particular project focused on using a commercial, off-the-shelf router to implement a residential automation system using Z-Wave wireless devices. The router can communicate status, and accept commands over a conventional 802.11 network, but does not require a remote host to operate the network. The router was reprogrammed using open source software, so it could issue commands, collect data, and monitor the Z-Wave network.

In this thesis, advanced interference management techniques are designed and evaluated for large-scale wireless networks with realistic assumptions, such as signal propagation loss, random node distribution and non-instantaneous channel state information at the transmitter (CSIT). In the first part of the thesis, the Maddah-Ali and Tse (MAT) scheme for the 2-user and 2-antenna base station (BS) broadcast channel (BC) is generalised and optimised using the probabilistic-constrained optimisation approach. With consideration of the unknown channel entries, the proposed optimisation approach guarantees a high probability that the interference leakage power is below a certain threshold in the presence of minimum interference leakage receivers. The desired signal detectability is maximised at the same time and the closed-form solution for the receiving matrices is provided. Afterwards, the proposed optimisation approach is extended to the 3-user BC with 2-antenna BS. Simulation results show substantial sum rate gain over the MAT scheme, especially with a large spatial correlation at the receiver side. In the second part, the MAT scheme is extended to the time-correlated channels in three scenarios, in which degrees of freedom (DoF) regions as well as achievability schemes are studied: 1) 2-user interference channel (IC) using imperfect current and imperfect delayed CSIT; 2) K-user BC with K-antenna BS using imperfect current and perfect delayed CSIT; 3) 3-user BC with 2-antenna BS using imperfect current and perfect delayed CSIT. Notably, the consistency of the proposed DoF regions with the MAT scheme and the ZF beamforming schemes using perfect current CSIT consents to the optimality of the proposed achievability schemes. In the third part, the performance of the ZF receiver is evaluated in Poisson distributed wireless networks. Simple static networks as well as dynamic networks are studied. For the static network, transmission capacity is derived whereby the receiver can eliminate interference from nearby transmitters. It is shown that more spatial receive degrees of freedom (SRDoF) should be allocated to decode the desired symbol in the presence of low transmitter intensity. For the dynamic network, in which the data traffic is modelled by queueing theory, interference alignment (IA) beamforming is considered and implemented sequentially. Interestingly, transmitting one data stream achieves the highest area spectrum efficiency. Finally, a distance-dependent IA beamforming scheme is designed for a generic 2-tier heterogeneous wireless network. Second-tier transmitters partially align their interferences to the dominant cross-tier interference overheard by the receivers in the same cluster. Essentially, the proposed IA scheme compromises between enhancing the signal-to-interference ratio and increasing the multiplexing gain. It is shown that acquiring accurate distance knowledge brings insignificant throughput gain compared to statistical distance knowledge. Simulation results validate the derived expressions of success probabilities as well as throughput, and show that the distance-dependent IA scheme significantly outperforms the traditional IA scheme in the presence of path-loss effect.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Wireless information transmission is easy to be suffered from various threats in an open environment. In this paper, we proposed a new type of software oriented secure system for direct wireless information transmission. We first present the special functions and requirements, which have to be satisfied during introducing the secure system. Then, we divide the secure system into three stages: normal operating stage, key presetting stage, and key replanting stage. The security, reliability and the computing complexity of this system are analyzed in this paper. Finally, we carried out this secure system by software and proved the availability.

Outdoor to indoor mobile coverage is evaluated for differentfrequencies in two scenarios, a single building scenario and a cityenvironment. A new model for outdoor to indoor propagation issuggested, connecting existing, highly detailed indoor and outdoorray-tracing propagation models. The model is compared to previous,site specific as well as statistical, propagation models. Resultsconclude that the new model gives higher path gain for edge users inthe single building scenario, whereas results from the city scenarioare inconclusive. Furthermore, results from the single buildingscenario suggest that indoor coverage is possible at 5 GHz and belowfor most buildings, whereas for the city scenario indoor coverage at5 GHz will be possible only for buildings without metally coatedwindows. Achieving indoor coverage at 30 GHz is highly problematicfor all cases, and it is concluded that indoor base stations arenecessary if frequencies of 10 GHz and above are to be used infuture mobile networks. In addition, an indoor analysis is made to verify existing lossper meter indoor models. It is concluded that such models are oftenoptimistic, although their assumption of log-normal shadowing remainvalid, at least for closed offices. Furthermore, the assumption ofloss as a linear function of distance might be unfeasible for higherfrequencies, where a breakpoint in the linear model was observed ata distance of roughly 10 meters.

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Wireless sensor networks have been used in different applications due to the advancement of sensor technology. These uses also have raised different optimization issues. Most of the algorithms proposed as solutions to the various optimization problems are either centralized or distributed which are not ideal for these real life applications. Very few strictly local algorithms for wireless sensor networks exist in the literature. In this thesis, we consider some of these optimization problems of sensor networks, for example, sleep-wake scheduling, mobile dispersion, mobile object monitoring, and gathering problems. We also consider the depth adjustment problem of underwater sensor networks. We design cellular automaton based local algorithms for these problems. The cellular automaton is a bioinspired model used to model different physical systems including wireless sensor networks. One of the main advantages of using cellular automaton based algorithms is that they need very little local information to compute a solution. We perform different simulations and analysis and find that our algorithms are efficient in practice. / Thesis (Ph.D, Computing) -- Queen's University, 2012-11-25 13:37:36.854

The coverage and energy issues are the fundamental problems which prevent the development of wireless sensor networks. In order to accurately evaluate the monitoring quality (coverage), one needs to model the interactive of sensors, phenomenons and the environment. Furthermore, in collaborative with scheduling algorithm and computer optimization, protocols can improve the overall monitoring quality and prolong the lifetime of network. This thesis is an investigation of coverage problem and its relative applications in the wireless sensor networks. We first discuss the realistic of current boolean sensing model and propose an irregular sensing model used to determine the coverage in the area with obstacles. We then investigate a joint problem of maintaining the monitoring quality and extending the lifetime of network by using scheduling schemes. Since the scheduling problem is NP hard, genetic algorithm and Markov decision process are used to determine an achievable optimal result for the joint problem of coverage-preserving and lifetime-prolong. In order to avoid the cost of centralized or distributed scheduling algorithms, a localized coverage-preserving scheduling algorithm is proposed by exploring the construction process of Voronoi diagram. Besides exploring the coverage characteristic in a static wireless sensor network, we investigate the coverage problem when the mobile elements are introduced into network. We consider the single-hop mobile data gathering problem with the energy efficiency and data freshness concerns in a wireless sensor network where the connectivity cannot be maintained. We first investigate the upper/lower bound of the covering time for a single collector to cover the monitoring area. Through our investigation we show that for a bounded rectangle area a hexagon walk could explore the area more efficiently than a random walk when the edges of area are known. We then propose a virtual force mobile model (VFM) in which the energy consumption for data transmission is modeled as a virtual elastic force and used to guide of mobile collectors to move to optimal positions for energy saving.

The focus of this study was to investigate solutions that, when implemented in any heterogeneous wireless network, shall enhance the existing standard and routing protocol connectivity without impacting the standard or changing the wireless transceiver’s functions. Thus achieving efficient interoperability at much reduced overheads. The techniques proposed in this research are centred on the lower layers. This because of the facts that WiMax and WiFi standards have not addressed the backward compatibility of the two technologies at the MAC and PHY layers, for both the baseband functions as well as the routing IP addresses. This thesis describes two innovate techniques submitted for a PhD degree. The first technique is to combine WiMax and WiFi signals so to utilise the same "baseband implementation chain" to handle both of these technologies, thus insuring ubiquitous data communication. WiMax-WiFi Baseband Convergence (W2BC) implementation is proposed to offer an optimum configurable solution targeted at combining the 802.16d WiMax and the 802.11a WiFi technologies. This approach provides a fertile ground for future work into combining more OFDM based wireless technologies. Based on analysis and simulation, the W2BC can achieve saving in device cost, size, power consumption and implementation complexity when compared to current side-by-side implementations for these two technologies. The second technique, called "Prime-IP", can be implemented with, and enhance, any routing protocol. During the route discovery process, Prime-IP enables any node on a wireless mesh network (WMN) to dynamically select the best available route on the network. Prime-IP proposes a novel recursive process, based on prime numbers addressing, to accumulate knowledge for nodes beyond the “neighbouring nodes”, and to determine the sequence of all the “intermediate nodes” used to form the route