The goal of this project was to develop a method that can control the power level of IEEE 802.15.4-based wireless devices by analyzing the incoming signal and steering the strength of the transmitted signal in a way that diminishes the power requirements while keeping an adequate signal. Local wireless networks connecting simple devices e.g. sensors or power switches, use the standard IEEE 802.15.4 and within it comes a number of built in methods for analyzing the quality of a signal. By studying their behaviour it is determined that the link quality indicator is best suited for these circumstances. Its statistical behaviour is studied for a range of power- levels to create a foundation for the simulations and to map the expected target areas. A model is constructed in Matlab and a method for power-steering is built. The method analyzes the statistical parameters of the last 16 messages of the incoming signal. Based on where these are in relation to the map created earlier a message is included to the other device about whether to increase or decrease the signal strength. To create more stability as soon as the signal is within the target area the number of sampled messages is increased to 160. This method is implemented on the IEEE 802.15.4-based wireless devices and the stability is observed. To explore the method further four different target areas are implemented for different requirements of the network and experiments are made with each.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-183802 |
| Date | January 2012 |
| Creators | Holmstedt, Elise |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | UPTEC F, 1401-5757 ; 12037 |
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