How it works: Broadband

It wasn't too long ago that getting onto the internet to check your e-mail involved getting everyone off the home phone and dialling up with a modem, and downloading a few megabytes of information was an agonizingly slow process. But fast cable and DSL broadband internet access in Canada have changed the internet experience for millions.

Canada has seen one of the fastest adoption rates for high-speed digital subscriber line (DSL) and cable internet in the world. The country ranked second in broadband internet penetration in 2003, and while it has dropped to ninth as internet use has exploded across the globe in recent years, Canadians remain big broadband users, according to statistics from the Organization for Economic Co-operation and Development (OECD).

Canada still has the highest ranking among the G8 countries, with an average of 22.4 broadband subscribers per 100 inhabitants.

While the adoption rate may be high, consumers are often unaware of the differences between cable and DSL.

With DSL and cable companies competing hard for your business, you've likely heard some of the pros and cons through their marketing pitches. Cable is generally faster than DSL — but only if you're not sharing the connection with too many people in your neighbourhood. Meanwhile, DSL speeds are more consistent, but tend to dwindle as the distance increases between the telephone switching station and the subscriber's modem.

These are good rules of thumb, but there's much more to each technology.

DSL consistent

DSL uses traditional copper phone lines, but in a way that's far faster and more convenient than a pokey old dial-up modem. DSL is an "always-on connection," which means the modem doesn't have to dial an internet service provider's number to connect to the internet. A DSL modem is constantly connected to the internet over your home phone line, and you can make voice calls on that line at the same time.

The standard system used in North America is asymmetrical DSL (ADSL), supporting data rates of about 1.5 to 9.0 megabits per second (mbps) when receiving or downloading data, and from 16 to 640 kilobits per second (kbps) when sending or uploading data.

Some service providers also offer "ultra high speed" or "high data rate" DSL connections for an extra fee. The caveat is that they tend to work best when the distance between the local telephone switch and the subscriber's modem is short. That means two subscribers with the same "ultra high speed" DSL service may actually experience quite different data transfer rates depending on their home's location. In most cases, you would need to be within a seven-kilometre radius of the switch that distributes the connection.

Cable faster, sometimes

Cable data rates also vary, but for different reasons. DSL uses a dedicated connection between the local switch and the subscriber's home or office, so the data speed stays fairly constant. A cable connection, on the other hand, is shared with other people on your street, which can lead to congestion when lots of others are surfing the web and downloading files at the same time.

A cable user might experience a slow connection in the evening when people are home from school and work and using the internet, for example, but a fast rate in the middle of a weekday when most of their neighbours aren't home.

If half the neighbourhood households are downloading large files simultaneously, for instance, everyone using the connection will see their data rates fall.

Rural subscribers have an advantage with cable, because there are generally fewer people nearby sharing the bandwidth. In urban areas where the number of users tends to be far more concentrated, the bandwidth is more likely to experience bottlenecks.

Cable does have one notable performance advantage over DSL: the coaxial cables used by cable service providers can handle a lot more traffic than a phone line. Cable internet is transmitted over unused television channels on the cable television system in a neighbourhood — some channels are used for data transmission (sending out e-mails or page requests to web servers, or sending a file to a friend, for example), while others are for receiving data, such as a web page or a file you're downloading.

At the most optimal conditions, cable internet subscribers could conceivably download files in much less time than their DSL counterparts. But this is assuming that the connection isn't being shared with anyone, a rare occurrence. This is also why cable providers tend to market their services as performing "up to" a certain speed, and often don't offer services based on specific speed levels the way DSL providers do.

Broadband use

The Canadian Radio-television and Telecommunications Commission (CRTC) reported that cable TV penetration in 2006 was close to 90 per cent nationwide. With that kind of footprint, coupled with Canadians' thirst for high-speed internet access, it's easy to see why cable providers have moved quickly to offer internet services. After almost a decade of offering DSL services, ISPs have also been able to roll out these services beyond the urban areas where they were initially made available, though the coverage area is still not as wide as cable.

But the debate over the benefits of cable versus DSL could soon be a moot point. Service providers are starting to move to fibre-optics, which promise a whole new level of speed and consistency.

A technology first developed in the 1970s, fibre-optics has mainly been used to transmit huge volumes of data across large distances. It's only recently that ISPs have slowly begun moving to fibre in larger Canadian urban centres like Toronto, Montreal and Calgary.

Fibre-optics is a method of communication where information is transmitted by light that forms an electromagnetic carrier wave through an optical fibre. Modems convert the optical signal into an electrical signal that computers and digital devices can read. It's an extremely fast way of transmitting huge volumes of data, allowing files containing entire movies to be downloaded in minutes. Distance from a switching station is not a big issue and download speeds to homes could go as high as 16 mbps on a consistent basis, meaning that you could transfer data without having to worry about sharing the signal or worrying about being too far from a switching station.

But laying fibre to homes is expensive, and it's not likely to displace existing DSL and cable internet services for the average internet service subscriber any time soon. So for now, it's up to subscribers to do their homework regarding the speed of local DSL and cable internet, and look for the option that gives them the best bang for their buck.