Introduction
DSL (Digital Subscriber Line) makes use of the unused frequency spectrum of the twisted pair telephone cables by carrying a digital signal without interfering with the voice service. DSL technology has evolved over the years with fibre reaching closer to the customers’ premises resulting in shorter copper loops. This has allowed twisted pair cables to exploit higher frequencies used in VDSL2 and G.Fast.
ETSI is very active in the definition of physical layer standards for DSL technologies including the specification of reverse power feeding typically for use with G.Fast. This technology enables powering of small network nodes from the customers premises over the same copper pair that carries the DSL or G.Fast signal.
Our Role & Activities
TC ATTM Working Group TM 6 is responsible for digital access transmission systems on metallic wired infrastructures (e.g. twisted pair, coaxial pair, power transmission lines/PLT), particularly for digital subscriber line systems (DSL) on balanced wired (twisted pair) Infrastructures and will produce within their scope:
- Specification of functional and physical characteristics of signals and interfaces on the physical line and at the network and the user side
- Frequency and spectrum management of bands allocated to these systems
- Specification of DSL filters and splitters
- Compatibility and co-existence studies between POTS/ PSTN and other technologies, particularly those sharing the same infrastructure
- Specification of reverse power feeding over twisted pair and coaxial cable