The scope of this work item covers the following point-to-multipoint (P-MP) applications: Voice, fax, voiceband data, Telex, Data up to 8 Mbit/s, ISDN. The main field of application of P-MP systems is to provide access to both public and private networks, particulary for remote subscribers. By means of P-MP systems the network service area may be extended to cover both distant and scattered subscriber locations. Subscribers to be offered a full range of services by the public/private network and to have access via various standard interfaces (2 wire loop, ISDN,....). The frequency bands above 3GHz are particularly suitable for the extension of telecomms. services to rural and suburban subscribers. P-MP systems provide standard network interfaces and transparently connect subscribers to the appropriate network node. These systems allow a service to be connected to a number of subscribers ranging from a few users to several hundred and over a range of distances. P-MP systems are generally, but not necessarily, configures as pre-assigned systems or as Demand Assigned Multiple Access (DAMA) radio systems. The essential features of a typical P-MP DAMA radio system are: - efficient use of the radio spectrum; - concentration; - transparency. Radio is often the ideal way of obtaining communications at low cost and almost independent of distance and difficult topography. Moreover a small number of sites are required for these installations thus facillitating rapid implementation and minimising maintenance requirements of the systems. Concentation means that m subscribers can share n radio channels (M being > n) allowing a better use to be made of the available frequency spectrum and at a lower equipment cost. The term multi-access derives from the fact that every subscriber has access to every channel (instead of a fixed assignment as in most multiplex systems). When a call is terminated the channel is released for another call. Concentration requires the use of distributed intelligent control which in turn allows many other operation and maintenance functions to be added. Transparency means that the exchange and the telephone communicate with each other without being aware of the radio link.
| Edition : | 1.1.1 |
| File Size : | 1
file
, 82 KB |
| Note : | This product is unavailable in Russia, Ukraine, Belarus |
| Number of Pages : | 25 |
| Published : | 11/01/1998 |
