By Akash Joshi

The focus in the Internet business is currently shifting. Most companies are now concentrating on the 'last mile' part, the line from their complex networks to user homes. In this, department, there are two technologies vying to attract the 'last mile' attention -- Internet over cable and Digital Subscriber Line, known as DSL.

While the concept of Internet over cable is quite clear and has been accepted globally, the DSL technology is still evolving.

Basically, as per the DSL technology, a single telephone line pulled into a home would provide both Internet access and telephone services at the same time. Again, same time!

Internet surfing would no longer interfere with the normal telephone. The telephone connection would operate independent of the Internet connection. More than that, the Internet connection would operate at extremely high speeds, as high as 10 Mbps, all round the day.There would be no need to dial up. For the telephone company this is good news because they will be able to continue using their copper wiring and provide this service.

Generally voice transmissions over the copper wire used by telecom companies are electrical impulses or analog in nature. They are converted, which is modulated or demodulated (mo - dem), using modems. Both the user and the telecom company have this equipment.

Digitisation or converting signals into digits (one and zero) means that they do not require as much bandwidth as analog signals do. Therefore, both analog and digital signals can be sent simultaneously over the copper wire.

The telecom company has to place a DSLAM or a DSL Access Multiplexer (DSLAM) at its central office and a splitter outside the consumer's home.

There are already indications that the DSL technology will challenge all other sorts of cheap high speed broadband Internet access, and this includes the cable access as well. According to International Data Corporation (IDC), a global telecom consultancy, by 2003, DSL technology will overtake cable modems in market share. Similar views are expressed by other Internet and media experts like Strategis Group and DataQuest.

In India, there have been efforts made by the Pune-based Dishnet, an Internet Service provider that uses the DSL technology to provide Internet access. It must be added that Dishnet has been extremely savvy in using both the cheap Internet access technologies -- DSL and cable.

MTNL recently announced that it would start offering DSL services by April this year. It would also allow other private ISPs to provide DSL servives by allowing them to place their DSLAM's at the MTNL central office.

If the cable operators thought that they had everything going for them, and that they had the wherewithal to score over other conventional ISPs, then they have another think coming. DSL technology has the potential to upset their calculations.