| 摘要 |
The present invention relates to improvements of or relating to cordless telephony and allows a DECT-system to be established at a comparatively low cost by use of the existing public telecommunications network. It further allows that the construction of the radio base stations are simplified and their costs reduced by placing certain functions in a local telephone exchange and to share these functions between radio base stations. Transmission between radio base stations and a local telephone exchange is simplified by the use of an ISDN-protocol, i.e. a transmission format based on the ISDN-standard which utilizes two B-channels with 64 kbit/s, and one D-channel with 16 kbit/s, over one single twisted copper connection. In a WACA-system according to the present invention, much of the higher control layers, for instance NWK and DLC, are placed in a central control unit, for instance located to a local telephone exchange. In this way the system layers can be made comparatively powerful. This makes it possible that subscriber equipment which introduces a radio base station can be simplified for instance by making the MAC-layer thinner. Consequently, the subscriber equipment is not quite independent since its fixed unit is at least partly remote-controlled. |
