Application Of MAP Protocols In Interworking Of PHS Network

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. Because PHS has the advantages such as: the low price, green, low radiation ,it conquers the market quickly ever since its development. It goes on expanding and developing. But 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 are needed .So it is very necessary that the networks of PHS could communicate with each other.There are many PHS manufactures in the market who use different accesses technology, network exchange link parameters. It's very 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 possible that the mutual communication of PHS could be implemented by using the same plan in the PHS core network. MAP protocol lies in the application layer of SS7 network, which is specially designed for the mobile subscribers. It regulates the procedures and modes of control and the data information exchange between the different function parts in the PLMN or the different PLMN. So It is very possible that China Telecom utilizes MAP protocol to make PHS network of different types interwork.This paper analyses the structure, message business of MAP protocol and the content of the conveyed message from different links of MAP protocol in the mobile communication networks. At the same time, the paper describers detailedly the system frame of IP-cored Softswitch PHS network. A solution of interwoking of different PHS core network is gived, and the paper describers detailedly the realization about voice short information and the missed call notification 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, the paper also modifies the modules about roaming and mutualcommunication in the MAP protocol of the mobile communication, designs message flow of the main function, SDL chart and codes in the modules about the management of mobility > the modules about the management of operation the modules about the management of calling, the author tests the HLR and VLR by many subscribers and system testing, which makes the mutual communication and roaming of MAP network come true.In the end, The work about this paper is summarized, and some problems which will need future research in this field are given.