Telecommunication systems

The purpose of this thesis is to investigate the ability of using piping networks as a communication channel using power line communication transceivers. Two ways by which a piping network is able to propagate waves are investigated. The first wave propagation method is through the pipe shell. Using structural waves and PZT type transducers, data packets are sent and received through the propagation of structural waves in the pipe shell. However, because of the dispersive behavior of quasi flexural radial waves, the data packets are distorted. The second wave propagation method explored is acoustic waves in the enclosed fluid. The data packets are sent and received along the piping network using three types of hydrophones. The reliability of this method depends mostly on the sensitivity of the hydrophones.

Multimedia conferencing has been making significant progress in recent years. There are many research projects and prototypes of this advance in interactive communications, however there is still no general abstract model. This thesis is primarily concerned with developing such a model that covers the major functions employed in a conference. Object Modeling Technique (OMT) is adopted here in describing both the static and dynamic aspects of this model. A relevant authorization system is also considered in this thesis. This system includes the description of an authorization model with general administration policies.

An Advanced Intelligent Network (AIN) is described and its performance is evaluated in this thesis. First, the AIN architecture is presented. This is followed by the description of the operation and the creation of the telephone services in the AIN architecture. Finally, the AIN architecture is evaluated on the performance of the user-network interface and the network elements, and the expandability and cost effectiveness of the architecture. The result of the evaluation shows that the operation of the telephone services in the AIN architecture are acceptable according to the standards set by Bellcore. Therefore, the AIN architecture meets the objectives set by the telephone operating companies and provides a basis for faster development and deployment of new telephone services in a cost effective manner.

The research addressed and reported in this dissertation primarily refers to the scope of characterizing modern telecommunication services as complex systems. The qualifying attributes, which allow such a characterization are three-folded: (i) Size of the network supporting massive traffics; (ii) heterogeneous characteristics of the traffics constituted by a mix of data, voice and video transmissions; and (iii) quality of service (QOS) considerations as met by a variety resources. Commensurate with the scope of the research indicated above, the underlying principles of information-theoretics are adopted as the background concept of the studies performed and a complexity-metric is defined via entropy considerations. Hence, the following aspects of modern telecommunications are studied: The first one refers to using entropy as a metric to assess the traffic characteristics in ATM telecommunications. Relevant heterogeneous traffic is modeled and analyzed in terms of the complexity-metric. Impairment considerations (such as cell-losses) due to queueing and/or finite-buffer sizes are estimated via information-loss specifications. The results are compared with those of conventional queueing-theoretics based analysis. The second consideration uses the complexity-metric to implement the so-called call admission control (CAC) in ATM transmissions. The complexity-metric is considered as a decision-theoretic parameter and a fuzzy inference engine is constructed to facilitate a real-time CAC. The third contribution of this research is pertinent to the development of an artificial neural network (ANN) implemented to perform CAC using the complexity-metric as the training parameter characterizing the input calls, which compete to get admission into the network. The real-time performance of the ANN in such CAC implementations is demonstrated. The fourth effort of this research is directed to portray the cybernetic perspectives of a complex system. Again, the interacting structure of the technology and economics of telecommunication systems is considered and the associated complexity is elucidated in terms of the entropy profile of the subsystems. Hence, optimized (or suboptimal) alternative designs of a network based on technoeconomical considerations are obtained. This dissertation also includes relevant literature survey and background details. It concludes with a discussion on the results and inferences on the research carried out. Further, the scope for future study is identified and open-questions are enumerated.

Body-proximate telecommunications devices are examined in both direct and multipath propagation. The study begins with a characterization of standard field strength sensitivity measurement methods for body-proximate telecommunications devices. Original measurements on a group of anthropometrically diverse people reveal that human adults, in a standard pose, are remarkably similar with respect to belt worn sensitivity performance, which motivates and justifies the use of an existing and a newly introduced light weight simulated human body device for testing, analysis and optimization of body worn telecommunications devices. Standard measurement methods using standard open air test ranges are established and validated by international transfers of measurements. The study extends to optimization of telecommunications devices in multipath, and particularly to the diversity reception of signals. A novel signal simulation model is introduced which includes multipath and shadowing, and is validated against both theoretical statistics and measurements. The signal simulation model is extended to characterize polarization randomization and cross-coupling based on an urban generalization of building height to street width ratio. The model is used to analyze measurements of polarization randomization of signals originating from an airborne transmitter flying a path whose geometry is consistent with low earth orbiting communications satellites.

This research is concerned with algorithmic representation of technoeconomic growth concerning modern and next-generation telecommunications including the Internet service. The goal of this study thereof is to emphasize efforts to establish the associated forecasting and, the envisioned tasks thereof include : (i) Reviewing the technoeconomic considerations prevailing in telecommunication (telco) service industry and their implicating features; (ii) studying relevant aspects of underlying complex system evolution (akin to biological systems), (iii) pursuant co-evolution modeling of competitive business structures using dichotomous (flip-flop) states as seen in predator evolutions ; (iv) conceiving a novel algorithm based on information-theoretic principles toward technoeconomic forecasting on the basis of modified Fisher-Kaysen model consistent with proportional fairness concept of comsumers' willingness-to-pay, and (v) evaluating forecast needs on inter-office facility based congestion sensitive traffics encountered. Commensurate with the topics indicated above, necessary algorithms, analytical derivations and compatible models are proposed. Relevant computational exercises are performed with MatLab[TM] using data gathered from open-literature on the service profiles of telecommunication companies (telco); and ad hoc model verifications are performed on the results. Lastly, discussions and inferences are made with open-questions identified for further research.