Single-pair high-speed digital subscriber line
G.SHDSL ( Global Standard for Single - Pair High -speed Digital Subscriber Line) is a symmetric DSL transmission technology in digital wide area networks.
In G.SHDSL the same data transfer rates are up, as in the downstream uses one or two pairs. G.SHDSL is a summary of ETSI standards SDSL and the ANSI standard HDSL2 and corresponds to the ITU standard G.991.2.
The original purpose of the G.SHDSL standards was to achieve equal the HDSL and SDSL standards by ITU and ETSI, a replacement for the classic E1 or T1 transmission using PCM technology over greater distances. Meanwhile, it is to be coupled via other components in the modem is possible ( eg router or switch functions) LANs or connect it to a LAN remote computer. For this purpose, the signal between the modems 16 to a TC (PAM trellis coded 16 -stage pulse amplitude modulation ) - transformed line coding with a maximum frequency of 550 kHz.
When using a dual core will transfer rates in multiples of 64 kbit / s 192 kbit / s to 2304 kbit reached / s. For 2- wire pair systems to reach a doubling of transmission rates in multiples of 64 kbit / s 384 kbit / s to 4608 kbit / s
With a core diameter of 0.6 mm, a distance of up to six kilometers can be bridged, which in practice is rarely achieved by external interference on the copper pair. A routing over such a long distance usually consists of several sections, of which the largest part is based of 0.35 mm cross section. And the junctions of the portions to increase the damping. In practice, the range of G.SHDSL hardly increased, but under the Protocol and the better error corrections, the link quality is more stable over shorter distances.
G.SHDSL is supposed to be backwards compatible with almost all popular HDSL and SDSL variations - with one caveat: The line coding of the relevant systems must match the line code of G.SHDSL.
An extension of the standard ( SHDSL ) allows data transfer rates up to 5,696 kbit / s Here, the area with TCPAM - 16 encoding to 3,840 kbit / s is extended and allows a new coding stage TCPAM 32 transfer rates of 768 kbit / s to 5696 kbit / s. The extended standard SHDSL.bis also defines a bundling of up to 4 copper pairs ( MPAIR ).