Shortwave Access Equipment. Softswitch Systems Research

With the Next Generation Network (NGN) being recognized by people, the Softswitch technology has been chosen to make the traditional telecommunication evolving into the NGN. During the course of evolution, techniques should be researched to make the legatary systems access to the unique package switch based Backbone. The objective of this paper is to research how to make the HF radio access to the NGN, which is based on Softswitch.Firstly, the system requirements have been acquired and the newest technologies have been collected. Then the architecture of the system has been setup, the protocols have been chosen and the detail design has been done according to the theory analyzed and simulated result. Finally, the HF Access Gateway and Remote Radio Controller prototypes have been realized according to the former design. A HF Access Demo System has been formed, which contains the HF Access Gateway and Remote Radio Controller prototypes together with a SIP proxy server, a SIP registrar and two SIP User Agents which come from the third party. With the help of the HF Access Demo System, Voice and Instant Message (IM) can be shared between the HF Radio user and the SIP terminal users who use SIPphone or Windows Messenger software on PC.The research result of this paper in Softswitch Based HF Access System requirement analyzed and realization may be useful for the standards issue of intercommunication between NGN and HF Radio System. Some skills, experience and lessons from this project may be noticed during the development of the actual HF Access equipments in future.