Metallic Cable

   There are two types of metallic cable, paired cable and coaxial cable.

   Paired cable is best for low bit rates i.e. 1.5 to 2 Mbits/s, while coaxial cable is suited for
       use higher up in the multiplexing hierarchy.

    Paired cable was originally developed for analogue lines. In digital transmission for example
       PCM links, crosstalk between wire pairs is a limiting factor.

    Coaxial cable is used in both FDM and TDM systems. Coaxial cable is characterised by a
        high bandwidth, which gives the cable a very high transmission capacity i.e. up to 10800
        speech channel in FDM. The coaxial cable is used in pairs, one for each direction. It is
        commonly used in the inter-exchange network where the traffic intensity is high.
 
 
 

     Optical Fibre Systems

    The optical fibre is a rapidly growing transmission media in the telephone network. This
         is because of it's remarkable characteristics : low weight, wide bandwidth, non-conductive,
         immunity to electromagnetic interference and low transmission loss.

    The optical fibre technology is has grown to become a very cost effective way for new
         telecommunications installations.

    Optical fibre systems is also widely used for intelligent building wiring and for Local Area
         Network (LAN) connections between computer systems.

    Extensive research and development is being carried in the area of optical switching
         which will make optical fibres even more useful and economical.
 
 
 
 
 
 

INDEX

HOME