PHS In-Building Distributed System Development And Feasibility Study Of The Multi-System Combination

Since being introduced to Beijing in 2000, In-building Distributed System has developed significantly in perspectives of both covering technology and construction scale. The construction of the PHS system at Beijing Netcom started from 2003, so far Beijing Netcom has built 800 In-building Distributed Systems covering area of more than 45 million square meters, including iconic buildings such as National Theatre, Beijing Western Railway Station, Beijing International Airport, Beijing Subways and etc. Today as the industry comes to a massive changing point with the issuance of the 3G network licenses and the integration of the network service providers, The PHS system is evolving into Point of Interface (POI) in order to utilizing existing resource in a cost-effective way while keeping the overall environment of the indoor space neat and comfortable. This article will first discuss the current status of the Indoor System from the research perspective, including the scale of the PHS network in Beijing, the topology of the network, the equipment implemented in the network, and the specifications and features of the network. Next the article will discuss the development trend of the PHS Indoor System, especially the evolution of POI, with analysis of critical aspects such as equipment, technical points and platforms. Then the article move on to conduct an in-depth discussion over specifications of isolation among systems, which is one of the most important technology factors to improve signal/noise performance in the POL The article will further work through a calculation of the minimal parameters of isolation according to the method of disturb analyzation and featured parameters among systems, the results could be used as a standard reference in design and implementation of the future POI systems.In the last part, the article will testify the analysis results with in-field project experience in national level telecommunication network cases such as the National Theatre project and the Ministry of Environment Protection project.