3 Brief Description of Current Systems of Internet Access

Dial-up
Still around is the old not so reliable Dial-up, which uses a modem in your computer to connect, via the existing telephone line, to another modem at the Internet Service Provider (ISP) and thereby to the Internet.
Apart from being slow, and very dependent on a good line, this system fully occupies the telephone line and thus phone calls are not possible at the same time.

DSL
Conveniently, the copper telephone line used all over the country to connect us to our local exchange does not utilise the full bandwidth available when making a normal voice call. Thus, by use of filters, it becomes possible to use the remaining bandwidth for data transmission, while making conventional telephone calls at the same time.
Unfortunately, however, since the lines were not originally designed to include data transmission, this system is limited to short distances, typically less than 5 km from the telephone exchange.
This method is the most common in use at the present time.

Probably the best known provider of this service is Eircom, who also owns all of the public service telephone lines between the local exchanges and homes and businesses. This has been known as ‘the last mile’ or ‘the local loop’. In effect, any other service provider, e.g. Esat, needs to lease or rent the line from Eircom in order to provide an alternative service with perhaps, more options.
ComReg (Commission for Communications Regulation) has for a number of years been negotiating with Eircom, to resolve Local Loop Unbundling. These discussions have now been concluded and ComReg is now in a position to provide clear guidance on timelines for the resolution on all matters pertaining to LLU . Eircom has now committed to resolving all of the identified issues – the vast majority by September 2007.
Accordingly, the function of DSL should show a gradual improvement.Refer to: http://www.comreg.ie/ and Status Update on Local Loop Unbundling - Issue 8.

Cable Modem
Many of our cities and larger towns are wired for cable television directly to your door. In a manner similar to DSL a broadband modem is used to take advantage of unused bandwidth in the cable television network, thus broadband and TV channels enter your house via the same cable.

Wireless Broadband
As the title implies this system does not require a telephone line; it functions by utilising a central transmitter/receiver, which has line-of-sight coverage because of its location, usually on high buildings or towers.
Wireless systems are currently available in cities and larger towns. To some extent they are being introduced in rural areas but are not regarded as cost-effective because coverage is limited due to the terrain.
Continual development is taking place, however, such that it is essential to update information on available systems.

Satellite Internet
Data from the satellite company is available via a satellite in stationary orbit.Mainly used for business purposes and has a number of disadvantages which make it not attractive for domestic use.

Broadband Via Mobile Phone Systems
Currently this system is more commonplace in business and is used typically in conjunction with laptops when away from the office.