Accessing And Data-Aggregation Of The Sensor Network On IoT Residential Gateway

IoT (Internet of Things) Residential Gateway is a connection and control equipment between the sensor network and the Internet. It is used to connect the Internet and the inner residential network including WiFi network and sensor network etc, and it is responsible for the data converting and forwarding. The thesis mainly studies how to access the sensor network node and process the relative data in the Residential Gateway under IoT architecture. The main research works are as follows:1. To establish the IoT Residential Gateway platform and Sensor Network platformThe thesis researches the current development of the sensor network and the IoT. It also studies the IoT network architecture, the relationship between sensor network and the IoT, and the application of sensor network in the IoT. We did the market researching and requirement analysis according to the IoT structure and the Residential Gateway's function. And then we establish the home gateway platform and the sensor network node developing environment.2. To implement the Sensor Network Access Module on IoT Residential GatewayWe bring out the requirement analysis of the sensor network's accessing module on Residential Gateway according to the existing Residential Gateway and sensor network's software and hardware platform. A designation to realize the Residential Gateway's sensor network accessing module by accessing the sensor network's sink node through the serial port is proposed. We design the accessing module flowchart, define the communication interface between the accessing module and the other modules, and accomplish the accessing module's preliminary design. Then, we design the accessing sub-module's processing flowchart and timing diagram according to the preliminary design, and the serial functions are programmed under the environment of embedded Linux operation system. As a result, the data collection and data forwarding between the sensor nodes and the other equipment in IoT are completed, and the Residential Gateway's sensor network accessing module is carried out.3. The aggregating process of the sensor network's data on the Residential GatewayThe sensor node's data need to be converted and forwarded after the Residential Gateway's accessing the Sensor Network. The sensor nodes are widely distributed and largely applied in the sensor network, and their length of packets is short. If the data collecting from each sensor node are forwarded directly, the effective payload in the transferring information would be low. And it would bring the network's congestion for the high frequency of sending data on the gateway. Considering this situation, a data aggregation module is added on the Residential Gateway and it can process the data packet collecting form the sensor network in real time. The aggregating process of the data can increase the effective payload transmitted, reduce the count of data transmission, improve the network transmission's efficiency, and improve the network throughput.The result of simulating the Residential Gateway Data Aggregation module shows that the aggregation module reduces about forty percent of the number of calling the data transmission module and improves the transmission efficiency. Moreover, we simulate the aggregating queue's length threshold in the aggregation algorithm and obtain the best aggregation queue length.