Research Of The SLP Protocol With Ability Of Context-Awareness

SLP which was proposed by SRVLOC of IETF is a service discovery protocol based on TCP/IP. Owing to the expansibility and characteristic of TCP/IP, SLP gained comprehensive support and many extensions were studied based on SLP in different applications.The basic SLP protocol is hard to select the best service among numerous services with the same function because lacking of intelligence. However, on account of the expansibility, it is feasible to add an intelligent mechanism to SLP. After studying carefully the mechanism of SLP, a context-awareness system is built on the SLP protocol, and a service discovery model with ability of context-awareness based on SLP is designed. So-called context-awareness system is the system which can sense the change of user environment and then change the behavior itself. SBCAS build a context-awareness system between the communication of UA and DA, it can filter the service candidates from DA to get the best fit one in current environment. The context-awareness system is composed of sensor, driver, context field, context scheduler and several other parts. It can aware of a lot of context information in current working environment with these sensors, then abstract the context field and use them to build a filter to select the service. The filter use the service candidates which come from DA as input, and return the filter result to user. The system can influence the whole query processing through this way, and can make the SLP protocol more intelligent.In the end of this paper, a simulating experiment is provided. It simulates a pervasive environment including several entities. By simulating the whole function of processing from service discovery, system running to service filtering. It is validated that the SBCAS can really help user to find the most proper service in current working environment.