No abstract

The wireless sensor network is an important element of energy efficient "Smart Buildings" to collect different types of data and to optimize the energy demand management (EDM) system. It is very important to save energy of the wireless sensor network to prolong the network life-time. In this thesis, a distributed, quasi-planned Medium Access Control (MAC) scheduling algorithm with priority control has been proposed for smart building's WSN. The protocol reduces the wasted energy of sensors during idle listening, collision, and overhearing processes. The system considers multiple classes of sensors based on their roles. The protocol establishes confirmed communication for steady traffic and gives adaptive control for varying traffic load. Hence, it reduces the total energy requirement for each sensor class. It uses a novel statistically inspired algorithm to dynamically configure the cycle length for reducing latency. Overall, the new algorithm shows better energy performance than many conventional WSN MAC protocols.

In Orthogonal Frequency Division Multiplexing (OFDM), frequency offset is a common problem that causes inter-carrier-interference (ICI) that degrades the quality of the transmitted signal. Many theoretical studies of the different ICIcancellation schemes have been reported earlier by many authors. The need for experimental verification of the theoretically predicted results in 2.4 GHz frequency band is important. One of the most widely used systems is Wi-Fi (IEEE-802.11b) that makes use of this frequency band for short range wireless communication with throughput as high as 11 Mbps. In this work, several new ICI cancellation schemes have been tested in 2.4 GHz frequency using open source Software Defined Radio (SDR) namely GNU Radio. The GNU Radio system used in the experiment had two Universal Software Radio Peripheral (USRP N210) modules connected to a computer. Both the USRP units had one-daughterboard (XCVR2450) each for transmission and reception of radio signals. The input data to the USRP was prepared in compliance with IEEE-802.11b specification. The experimental results were compared with the theoretical results of the new Inter-Carrier Interference (ICI) cancellation schemes. The comparison of the results revealed that the new schemes are suitable for high performance transmission. The results of this paper open up new opportunities of using OFDM in heavily congested 2.4 GHz and 5 GHz bands (Wi-Fi: IEEE 802.11b) for error free data transmission. The schemes also can be used in other frequencies where channels are heavily congested.

No abstract

The wireless sensor network is an important element of energy efficient "Smart Buildings" to collect different types of data and to optimize the energy demand management (EDM) system. It is very important to save energy of the wireless sensor network to prolong the network life-time. In this thesis, a distributed, quasi-planned Medium Access Control (MAC) scheduling algorithm with priority control has been proposed for smart building's WSN. The protocol reduces the wasted energy of sensors during idle listening, collision, and overhearing processes. The system considers multiple classes of sensors based on their roles. The protocol establishes confirmed communication for steady traffic and gives adaptive control for varying traffic load. Hence, it reduces the total energy requirement for each sensor class. It uses a novel statistically inspired algorithm to dynamically configure the cycle length for reducing latency. Overall, the new algorithm shows better energy performance than many conventional WSN MAC protocols.