What is a DSL modem? And how does it work? If you’re reading this at home, there’s a very good chance you’re accessing the internet through either a DSL or cable modem, especially if you’re using a home computer. You’re probably aware that the modem in question allows the different devices in your home – your computer, phone, tablet, TV, Blu-ray player, and maybe even your fridge – to connect to the internet for the purpose of sending and receiving data.
Nowadays you can potentially have those same devices be online via your cell phone’s mobile hotspot, but there was a time when it was simply a case of no modem, no internet access.
The Birth of Home Internet
Although the internet, in some form or another, has been in existence since 1969, it wasn’t in common use by the general public until the early to mid-1990s.1 At around that time, the popularity of cell phones was increasing, and as a result, the demand for regular landlines was dropping. This left the phone companies with a network of copper cables that began to fall into disuse, causing the telecommunications industry to repurpose them for the internet.
Unfortunately, the telephone network was originally designed to carry voice signals within a specific bandwidth, which limited data transmission rates to 56 Kbps. However, given the simplistic nature of websites at that time and the minimal amount of data being transmitted, this wasn’t a problem in itself, but there was a bigger issue: internet data was sent over the same frequencies as voice signals. This restriction limited customers to using one or the other, but never both simultaneously on the same line.2
DSL provided the solution.
How DSL Changed the Internet
The technology for DSL (Direct Subscriber Line) had been in existence since the 1980s and was originally intended to be used by cable TV providers.3 Since DSL made use of the other frequencies carried by the phone network, it was introduced in the early 1990s for on-demand television. but was unable to gain a foothold in the industry.
When home internet exploded, so did the technology. Websites became more advanced, webcams boomed in popularity and the number of users across the world multiplied exponentially. The demand for data and the need for speed increased correspondingly, and the internet service providers found themselves in an increasingly competitive environment.
Suddenly DSL started to look like a very attractive option, as it allowed the phone companies to take advantage of the existing copper wire infrastructure without needing to pay for upgrades. Utilizing the unused frequencies allowed for much faster speeds while also freeing the frequencies used for voice signals. This allowed customers to surf the internet and talk on the phone at the same time and, as an additional bonus, customers no longer needed to “dial up” the internet but could remain permanently connected instead.
The Different Types of DSL Connections
Essentially, there are three types of DSL connection:
- SDSL (Symmetric Digital Subscriber Line) – So-called because users would have equal upload and download speeds, SDSL had the disadvantage of causing significant interference that slowed data transmission rates.
- ADSL (Asymmetric Digital Subscriber Line) – Since most users upload very little data but download exponentially more, ADSL allocates more bandwidth for downloading. This, in turn, significantly reduces electrical interference in copper lines and allows for maximum speeds of around 3 Mbps.
- VDSL (Very high-speed Digital Subscriber Line) – First introduced in 2006, VDSL uses fiber optic cable to provide much faster speeds than either of its predecessors. With VDSL, you can typically expect speeds of up to 100 Mbps.
The Pros and Cons of DSL
DSL is an obvious upgrade from the inconveniences of a dial-up connection, and since it takes advantage of the existing phone network, it’s available almost everywhere. However, it’s not without its disadvantages. For starters, the actual speed customers receive will depend upon their distance from the telephone exchange; the further the customer is from the exchange, the slower their speed.
Another problem is that VDSL can cost more, as it requires fiber optic cable rather than the standard copper cable used by SDSL and ADSL.
There is, however, an alternative. If you subscribe to an internet service through your cable provider, you’ll be using a cable modem to go online. This type of modem can provide faster speeds, is more reliable than DSL and isn’t affected by your distance from the nearest exchange. The downside? This type of internet access may not be available everywhere, especially if you live in a rural area, and it’s a good idea to check out your options before signing with any one provider.
Whether you have some variation of DSL or a cable modem, the internet has come a long way since the 1990s. From a time when websites could take minutes to load and streaming was unheard of, we now live in a world of constant communication, interaction and entertainment – and that’s thanks, in no small part, to the humble DSL modem.
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- Shedden D. Today in Media History: The Internet began with a crash on October 29, 1969. Poynter.org. Published October 29, 2014. Accessed December 28, 2021.
- Technology.org. The Brief History of the Internet: From Dial-Up to Blogs to AI. Technology.org. Published October 19, 2018. Accessed December 28, 2021.
- The Editors of Encyclopaedia Britannica. DSL. Britannica.com. Updated November 16, 2021. Accessed December 28, 2021.