Buying Guide - Modems


While most laptop and desktop PCs come with a modem these days, upgrading your modem can dramatically improve the performance of your device. Modems are used to control the flow of an analogue signal to encode digital information - a process called modulation. At the same time, they demodulate the incoming signal to decode the carried digital information, allowing you to access the worldwide web.

modemDespite sounding like a modern word, modems have actually been in existence since the early part of the 20th century. Originally developed in the 1920s, the evolution of the modulator-demodulator - or modem for short - was pushed into overdrive by the US Air Force in the post-war years as a way to transmit hundreds of radar images quickly and conveniently.

With broadband internet now eclipsing its slower, dial-up cousin, ADSL modems are the must have units, providing faster connections and download speeds than ever before. Standing for asymmetric digital subscriber line, ADSL modems are so called because they support different data rates for sending and receiving data, as opposed to the symmetric digital subscriber line - or SDSL - modems, commonly employed in mainland Europe, which operate the same data rates for each process.


The first thing to take into account when purchasing a modem is compatibility. After all, there's no point buying a high-speed modem if it's not going to work with your system.

Broadband internet requires that the computer have at least USB 2 connectivity to connect to the modem and router. Version 2 of USB is rare on devices made before 2002, so if your system is not equipped with this you will need to invest in a network port.

Exercise bikeAlternatively, ethernet cables can be used to connect between modems and routers. Many computers will support Ethernet connections straight out of the box. If not, then 10/100Base-T adaptors are cheap and easy to come buy. To eliminate any confusion, Base-T, IEEE 802.3 and CSMA/CD are, for all intents and purposes, the same thing.

Another thing to take into consideration is the operating system your device runs. The competitive world of computer operating systems and hardware means that companies usually try to safeguard their own survival by making their products incompatible with systems from other companies. This is most prevalent with operating systems from Microsoft and Apple, where a general rule of thumb is "if it's made by one company, it won't work on the other’s operating system". However, it is vital to check the compatibility list and the system requirements of the modem on the packaging.


Modem speed is measured in Bps, which stands for bits per second. A 'bit' is a single binary pulse used to transmit data. As this is a very, very small unit, modem speed is usually represented as Kbps, a thousand bits per second, or Mbps, a million bits per second.

This is the amount of information that modems and routers are able to process in one second. Dial up modems can handle 56 Kbps, with ADSL modems, which are used for broadband connections, allowing much higher levels of information to be processed.

Generally speaking, the higher the Bps value the better connection. ADSL modems can provide connections of up to 50Mbps, a whopping 892 times faster than dial up. With such a vast range of speeds and capabilities, selecting the right modem and router for you is really a case of assessing your individual needs.

If your monthly usage consists of sending a few daily emails and checking the football scores then it's hardly worth shelling out big money for an ultra-high speed connection. A connection of around 500 Kbps will suffice. On the other hand, if you're an avid online gamer wanting to stream HD content in fluid detail, then a speedy connection - of about 8Mbps - is vital.

What kind of modem?

Following on from the discussion about which speed of modem to go for, the question of which kind of modem to opt for follows similar lines. The question boils down to what sort of usage you expect to get out of your modem. The modern society tends to force broadband modems and routers down our throats, when really a dial-up modem may suit your purposes better.

If you are a low usage customer, with no use for streaming video content or downloading music then a dial up connection may suit your needs better than an ADSL modem.

A 56k dial-up connection does have its advantages. Its 'pay for what you use' nature means that a low usage customer won't be getting ripped off by paying a needless monthly tariff. Furthermore, the lack of a binding contract means a dial-up user has the freedom to change provider as and when they need to, unlike a broadband customer who will be tied to a single provider for a minimum period.

However, the broadband internet provided by an ADSL modem gives the user the benefit of a wireless router, allowing anyone in the household to access the internet via a password protected connection. This obviously gives users more flexibility. Also, the more competitive monthly tariffs often work out cheaper than using a dial-up connection.


While it may be tempting to go for the highest Mps connection available with your budget, this may not be the best modem for the job. While an ADSL modem and broadband connection with a gargantuan data processing rating is undoubtedly the "best" method of connecting to the internet, the amount of money you will spend on this connection renders it almost pointless.

Such huge connections - 20 Mbps onwards - aren't really designed for domestic connections and are marketed more for businesses with large numbers of internet users logging on simultaneously. It is best to analyse your internet usage, or planned internet usage before shelling out on a modem and router.

At the same time, it might not be worth writing off a reversion back to the days of 56k dial up internet. Individual users with low usage requirements can potentially save money with a pay per use dial up connection and modem.