Study of Wired and Wireless Data Transmissions

University dissertation from Linköping : Linköping University Electronic Press

Abstract: The topic of this dissertation is divided into two parts where the first part presents high-speed data transmission on flexible cables and the second part presents a wireless remote monitoring and controlling system with wireless data transmission.The demand on high-speed data communications has pushed both the wired and wireless technologies to operate at higher and higher frequencies. Classic Kirchhoff’s voltage and current laws cannot be directly applied, when entering the microwave spectrum for frequency above 1 GHz. Instead, the transmission line theory should be used. Most of the wired communication products use bit-serial cables to connect devices. To transfer massive data at high speed, parallel data transfer techniques can be utilized and the speed can be increased by the number of parallel lines or cables, if the transfer rate per line or cable can be maintained. However, the lines or cables must be well-shielded so the crosstalk between them can be minimized.Differential lines can also be used to increase the data speed further compared to the single-ended lines, along with saving the power consumption and reducing the electromagnetic interference. However, characterization for differential lines is not as straight forward as for single-ended cases using standard S-parameters. Instead, mixed-mode S-parameters are needed to describe the differential-, common- and mixed-mode characteristics of the differential signal. Mixed-mode S-parameters were first introduced in 1995 and are now widely used. However, improvements of the theory can still be found to increase the accuracy of simulations and measurements, which is proposed and presented in this dissertation.The interest of wireless solution to do remote control and monitoring for cultural building has been increasing. Available solutions on the market are mostly wired and very expensive. The available wireless solutions often offer limited network size with point-to-point radio link. Furthermore, the wired solution requires operation on the building, which is not the preferred way since it will damage the historical values of cultural heritage buildings. Wireless solutions on the other hand can offer flexibility when deploying the network, i.e., operation on the building can be avoided or kept to the minimum.A platform for wireless remote monitoring and control has been established for various deployments at different cultural buildings. The platform has a modular design to ease future improvement and expansion of the system. The platform is based on the ZigBee standard, which is an open standard, specified with wireless sensor network as focus. Three different modules have been developed. The performance has been studied and optimized. The network has been deployed at five different locations in Sweden for data collection and verification of the system stability.The remote monitoring and control functions of the developed platform have received a nomination for the Swedish Embedded Award 2010 and been demonstrated at the Scandinavia Embedded Conference 2010 in Stockholm.Communication