SHDSL technology complementing other transport technologies

We describe SHDSL modem application domains according to area network types that carry data. SHDSL modem is described and its use in transcoding applications to interconnect different interfaces. In its most basic form, each interface is transported over the same area network it was designed for (E1 - PDH, X.21 and datacom - X.25, Ethernet - LAN). We show that these interface types can be mixed and matched to different network types by using transcoding properties of the described SHDSL modem. Furthermore, it can be used as a speed adaptation unit, where interconnecting interfaces operate at different data rates. E1 links can be carried over SDH backbone and stretched via SHDSL to remote end. In similar application, modem can be successfully used in reusing current E1-SDH PVCs to carry transparently Ethernet or X.21 traffic. Both ways of transmission are completely independent to achieve minimal transport delays. Applications include use of existing telecommunication infrastructure for providing various symmetrical two-way data services as video-on-demand, videoconferences, remote education, etc.