Access Angles: Part 1
Speed: We all crave it; whether it's a factor in our car's performance, our computer's 'usability,' or in the often interminable wait many of us face while attempting to download (or upload) a file over a network or through the Internet. But it is the speed with which we are able to manipulate files across the Internet which has the greatest impact on 'the overall computing experience' for many of us, and that forms the foundation of the equation that determines this speed is the type of Internet access we enjoy. For many of us, the choices in this regard are no longer as simple as they once were, since the technology, and our market conditions, are constantly evolving; and it is with this in mind that we present this series on Internet Access, and the latest high-speed options available to the public. Enjoy! ~ Stephen
One of the most confusing issues for new computer users is the hype that's going on between different Internet access providers, or ISPs as they are called. Dial-up modem, cable modem, digital subscriber lines (DSL), wireless, and satellite access are all options currently available to the average consumer, but which is the fastest (and most reliable) of these? In this series we'll look at each of these Internet access methods in a fair amount of detail and show you the advantages and disadvantages of each.
Understanding the Basics
Internet access speeds are often referred to in k, or kps. kps stands for kilobits per second, and stands for a specific amount of data sent through a signal. In order to understand comparative data transfer speeds, you must first know the basics of the computer language.
Computers use a language of 0's and 1's. A bit is a single 0 or 1 in the computer language. When you put 8 bits together, you get 1 byte. 1 byte is the equivalent of 1 individual character. For example, when you type the letter A, the computer sees the "A" as 1 byte of information (technically — using fonts and stuff, this is incorrect, but for simplicity sake, for our purposes the letter "a" is equal to one byte).
When you talk about file storage, you talk in K, which is kilobyte. 1K is equal to 1024 bytes. When you talk data transfer like modems, you talk in kbps, or kilobit per second. 1k is equal to 1024 bits, or 128 bytes. This is why a 100K file isn't downloaded in 2 seconds on a 56k modem. It actually takes 8 times as long, because 100K is equal to 800k. Remember this basic "Kase sensitivity" for later.
Dial-up Modems — Life in the Slow Lane
Since the earliest days of computers, the desire to hook up two systems over long distances was always a challenge. In order to do this, a method of sending a data signal over a normal telephone line had to be found. This process is called MOdulation / DEModulation, short-formed to modem.
Modulation and demodulation is required because telephone lines use analog signaling, where computers are digital. In order for a computer to talk across a phone line, it first had to change its signal into a format that the phone could understand. This is called modulation. The process of converting the signal back to digital is called demodulation.
Modems are serial connections. That means that they send one signal at a time over the telephone line. In the early days of modems, you could actually talk on the same line to the person on the other computer while the modem was sending. As modems became faster, they required more and more space on the phone line to send signals, and ended this ability.
Most of us use 56k modems to connect to the Internet, although older systems still have 33.6k or 28.8k modems in them. The number (such as 56) is the fastest transfer speed that a modem can send and receive information. A 56k modem can send 56kilobits of information per second, or about 7Kilobytes per second. Under the best circumstances with a 56k modem, you will get about 5.5Kbps transfer. This means a 100K file will take about 18 seconds. Noisy phone lines, bad switches, and cheap modems will decrease your chances of attaining these speeds, and speed varies by Internet access provider.
Still, "dial-up" is the cheapest (it's even free in some cases), most reliable, and widely available form of basic Internet access, and a wise 'back up' to more exotic (and failure prone) systems, or for use when traveling. Cable is considered to be 'broadband' Internet access, because everyone on the cable network sees the signal to and from your computer.
Cable Modems — Life in the Fast Lane
When looking for much faster data transfer, networking specialists found an easy method of using existing technology to speed up access. This is called a cable modem, and uses the cable TV wire already installed in your home. Since many networks already run on a cable very similar to cable TV wire, it was just a matter of adapting the signal so computers could understand it.
Cable is considered to be 'broadband' Internet access, because everyone on the cable network sees the signal to and from your computer. This varies from telephone signals, which are only seen on your phone line, and called 'baseband' transmissions. The primary advantage of these broadband transmissions is that the provider's don't have to dedicate a wire to you and you alone; everyone on the network can share the same basic wiring. The other big advantage of broadband is that it's always 'on,' whether you're at your computer or not.
Cable Internet access is sold in many different ways. Most times, you buy it with a limitation on the amount of bandwidth, or the amount of data per second, the provider allocates for you to use. This can range from 128kbps to 512kbps. Basically, you will pay more for faster service, and for 'business' use. The average cable plan offers about 256kbps transfer. Some will offer faster access at a premium price, but as more and more people sign up the data rates tend to fall to slower levels than the 512kbps packages many providers offer. So for argument's sake, we're going to assume you get a steady 256kbps transfer. Our 100K file now takes only 3.1 seconds to download.
While cable Internet access is not available everywhere, it is being rapidly implemented, and its cost is quite reasonable, with 'free installation' and 'free modem' offers being quite commonplace, and a reliability factor that is not based on weather conditions, as is satellite based access, which we'll discuss later.
In our next installment, we'll look at Digital Subscriber Lines (DSL) Internet access.