The Design And Implementation Of SIP Based Managing And Control System For Smart Electricity

The basic function of the Smart Electricity System is to integrate technologies including the measurement of real-time electricity power, automatic control, network communication, etc. And the goals of the system are to realise visible, manageable, schedulable, automatically planned electricity consumption and so forth. The Smart Electricity System is consisted of some smart electricity outlets and one Smart Electricity Gateway. The differences between smart electricity outlet and common outlet is that smart electricity outlet is able not only to supply power to electrical appliances, but also to support measuring real-time power consumption, automatically control the switch of the electrical appliance which is connecting to it and so on. With the help of Zigbee or other wireless communication technologies, the Smart Electricity Gateway communicates with smart electricity outlets, implements the acquisition of real-time power, and the interaction of command or state of switches, etc. The Smart Electricity Gateway is the managing and control facility of the Smart Electricity System. For the convenience of system management, the Smart Electricity Gateway should also possess the mechanism of the accessory to the system through Internet and telecom network.The target embedded Smart Electricity Gateway adopts LPC1788microcontroller (based on ARM Cortex-M3) as the core hardware, which communicates with Zigbee coordinator via serial port. Making use of the serial port, the gateway can furtherly communicate with smart electricity outlets existing in the Zigbee network. The gateway integrates standard Ethernet network interface, and joins the telecom IMS network by means of TCP/IP protocol. The IMS terminals, running on smartphone, pad or PC and so on, are able to access the Smart Electricity Gateway, thus helps to realise the management and control of the Smart Electricity System. The objective of this thesis is to design and implement a kind of embedded Smart Electricity Gateway that supports accessory to the Smart Electricity System through the telecom network.Upon the bases of fully understanding the required target functions, analyzing the architecture of LPC1788microcontroller, and studying some related communication protocols, the main work that this thesis has accomplished is summarized as follows:1) The μC/OS-Ⅱ Operating System is ported to LPC1788, the TCP/IP protocol stack is constructed and PJSIP, an open-source SIP protocol stack, is ported to the OS;2) The communication protocol between the gateway and the Zigbee coordinator is designed, and the program for serial communication is implemented;3) The software architecture for the Smart Electricity System is designed, including related data structure, multitasking interfaces of "serial data processing, network data processing, timer managing, SIP UA processing" and a synchronized mechanism is designed for reading and writing data buffer among tasks, which helps to realise efficient data collaboration among multitasks.4) Based on the PJSIP stack, the functions of the standard SIP terminal are designed and implemented, the SDP protocol is extended to support data interaction of the Smart Electricity System, the STUN client is implemented which supports data interaction for NAT traversal. This thesis implements a SIP supported embedded Smart Electricity Gateway, through which any terminal can manage and control the Smart Electricity System by IMS signals through the Internet or the telecom network, thus contributes to the popularization and application of the Smart Electricity System.The achievement of this thesis has passed the test and validation of Liaoning Planning and Designing Institute of Post and Telecommunication Co.Ltd, and has satisfied the designing target, and has been integrated into the related product for practical application.