Study And Realization Of The PHS Systems' Inter-Working Based On MAP/CAP

PHS (Personal Handy-Phone System) is the easy name of the wireless telephone. It is a kind of personal access system attached to the settled telephone which could realize wireless covering by micro comb technology. It conquers the market quickly ever since its development and it goes on expanding and developing. But because the time for the development of PHS is very short, different manufactures do not have the same standard, and the different networks existed in the same city. So it is very necessary that the networks of PHS could communicate with each other.There are many PHS manufactures in the market which use different accessing technology, network exchange and link parameters.So it's difficult to make PHS inter-communicate in the technology field. PHS technology is "grafting" on the settled telephone network, but the telephone network could convey the information by SS7, so it is very possible that China Telecom utilizes MAP/CAP protocol which is common used in GSM system to make PHS networks of different type inter-work.Firstly, this paper analyses the structure of IN(Intelligent Network), and then focuses on the analysis of IN's core part—BCSM(Basic Call State Model)。Introduce the structure, message, business of MAP/CAP protocol and the content of the conveyed message from different links of MAP/CAP protocol in the mobile communication networks. On base of it, drew lessons from the mutual communication of SoftSwitch and Intelligence Network, combine the conception of SCP/SSP (Service Control Point/ Service Switch Point) in IN, a solution of inter-working of different PHS core network is given. The paper describers detailedly the realization about subscriber authentication, subscriber register, call, account roaming expenditure by this way. This solution adds HLR Adapter and VLR Adapter in the softswitch network of PHS, which could realize the exchange of SNSP and MAP and solves efficiently the exchange problems of the information about subscribers' position in different networks. This solution also adds Service Engine which functions as a stack adapter, it can provides stack functions which transfer the CAP message based on SIGTRAN into inner CAP message based on SNSP. It also adds Feature Server as an isolated network entity which acts as SCP in the entire network and provides an integrated communication platform to save the service logic of IN service such as prepaid service. The author tests the HLR, VLR and Prepaid service by many subscribers and system testing, which makes the mutual communication and roaming of different PHS networks come true.