Research On Key Technologies Of Smart Home Architecture Based On The Internet Of Things

The Internet of Things (IoT) is a novel paradigm about network which exceeds the Internet. The core idea of IoT is the pervasive presence of various things or objects around us-such as radio frequency identification (RFID) tags, sensors, actuators, mobile phones, etc.-which, through unique addressing schemes, are able to interact with each other and communicate with their neighbors to reach the common goals. As one major sub-filed of IoT. smart home is a dwelling incorporating a communications network that connects the key electrical appliances and sensors, and allows them to be remotely controlled, monitored and accessed. Smart home aims at providing comfortable, healthy and secure environment for residents. The research about smart home is still in its infancy, there are some issues required further consideration. For example, a robust and flexible network configuration mechanism is required to configure home sense nodes and home control nodes in the network layer. An integrated communication protocol is required to complete communications between home nodes. An efficient and robust system architecture is required to provide efficient services for residents. For the purpose of addressing these issues, this paper analyses related protocols and technologies in home network construction, home network communication and system architecture designing, and promotes the research to cover these issues. The contribution and innovation of this paper are described in detail as follows.1. This paper constructs a flexible and robust home network which achieve high address utilization ratio and high robustness. By virtual of analysis and comparison about wired and wireless networking technologies, this paper proposes a robust and flexible sharing architecture of home networks within residential buildings based on IEEE802.15.4. All home networks in one residential building share the whole address space of one IEEE802.15.4network, which aims at solving the confusion problem in adjacent home networks. The home-id code is designed for identification of home networks and speeding rescue operations. The half-satisfy mechanism of the proposed solution improves the flexibility and the address utilization rate of home networks. Enhancements of the proposed mechanism are designed for the insufficient address space at a certain depth, migration of nodes and abrupt departure of nodes, aimed at improving stability and robustness of home networks. One simulation program of the proposed solution was coded based on the NS-3platform. Simulation results demonstrate that the proposed approach can effectively restore home networks following the destruction of sub-networks and nearly80%address utilization can be achieved in residential buildings.2. This paper proposes a integrated home network communication protocol based on6LoWPAN. Due to its advantages of small size system code and low requirement of RAM,6LoWPAN is used as the basis of communications in home networks. Detailed description is given about LoWPAN_CHl header format and a new header format (LoWPAN_SH) is defined for the proposed smart home system. LoWPAN_SH header eliminates the address type label, the traffic class and flow label, the next header label and the HC2encoding label of LoWPAN_CHl header. So LoWPAN_SH header takes less space than LoWTAN_CHl. Integral definition is completed for header format and inline parameters of home control messages, home warn messages, state inquiry messages and nodes set messages. Analysis about the format of LoWPAN_SH header demonstrates that it achieves standardization, extensibility, lightweight and statelessness.3. With comparison and analysis about large software architectures, including OSGi platform, distributed OSGi platform and distributed object technologies, this paper proposes a distributed service oriented architecture for smart home systems. In the proposed architecture, the distributed bundle is designed for remote hot deployment of bundles and remote procedure call of services. In order to reduce the network load of the system and the computation load of the system server, the P2P bundle is responsible for establishing direct communication channels between the system terminals. The communication mechanism of the proposed architecture, defined based on hyper text transfer protocol (HTTP), extensible markup language (XML) and simple object access protocol (SOAP), achieves independence, standardization, statelessness, extensibility and efficiency. A prototype for the proposed approach is completed to demonstrate its effectiveness. Simulation results show that the proposed system can save up to37.5%network load on condition of75%requests handled by corresponding home gateways. And it achieves65%improvement than the server centric system in response time when the requests sending rate send rate closes to the server processing rate.4. On the basis of the prior research accumulation, this paper finishes the designing and implementation of a smart home system prototype. This prototype contains the system client, the home network and the system server. This paper gives illustration about the outline design and detailed design of the system client program, the home network and the server program, including system function modules and system interface, communication process and the architecture of the system server. This paper gives the description of the implemented system prototype, including the user interface (UI) of the system client, the hardware of the home network devices and the key code of the system server. The implementation of the system prototype make it feasible to construct an experimental smart home Lab, which can be used to collect data of user behavior and energy consumption for data mining and achievement of intelligence.