Copper telecom cable has long been the preferred material for both long and short-range communications, enjoying steady growth throughout the last 50 years.
In the 1980s, copper benefited from the fax revolution. Many second telephone lines were installed to service it. More recently, the internet prompted many people to install additional lines and, of course, the normal growth of the housing stock, along with home offices and growing affluence in general, has increased the number of telephone lines in service.
At the same time, technological developments have brought about fundamental changes in data transmission, notably through the emergence of satellite communication, wireless communication and increased use of optical fibre, as well as growth in the cable company market.
Whilst copper product usage has been affected, it is far from becoming obsolete. On the contrary, copper is present in some shape or form in most of these technologies. In addition, it forms an integral part of exciting new transmission processes, HDSL and ADSL (High Digital Subscriber Line and Asymmetrical Digital Subscriber Lines) that can extend the message-carrying capacity of existing twisted copper wire pairs to that of optical fibre without the expense of switching systems.
Recently introduced xDSL technologies such as VDSL & SHDSL, made possible through multiplexing technology, enable existing twisted wire pairs to carry much larger signals, enabling high speed data transmission.
A significant technological development in this area is in the field of DSP (Digital Signal Processing). Special hardware, attached to both the user and switch ends of the line, allows data transmission over the wires at far greater speed than the standard cable phone wiring.
One primary advantage is that lines are open 24 hours a day. Another is that this technology uses different parts of the available spectrum to carry voice and data, with the ability to use both simultaneously.
Besides internet-type data transmission, xDSL applications are expanding to include remote LAN access, video conferencing, medical diagnosis, distance learning and video on demand.
Wireless, Optical Fibre, Cable
Wireless communications, satellite information relays and the increased use of optical fibre are also recent developments in the field of telecommunications. Contrary to what one may think, they do not necessarily mean the end of copper.
As 'traditional' analogue voice telephony systems are upgraded to digital systems, more copper wire and alloy products are required for use in the telephones and base stations that permit wireless communications. Even in optical fibre systems, copper is still used extensively in interface devices.
The telecommunications market is evolving fast. Thanks to new technologies that allow compression as well as bandwidth broadening, copper cable networks can now be used to deliver broadcasting and high-speed interactive services, without being significantly constrained by their capacity. The new contenders for data transmission, cable companies, hope to capitalise on available bandwidth on existing co-axial copper cables to pick up some of the internet-derived business opportunities. Time will tell how the current balance will shift between the different systems in operation.