In our first installment, we looked at the basics of computer data transfer, along with dial-up modem and high-speed cable modem based broadband access. Our second installment looked at arguably the most popular form of high speed access: Digital Subscriber Lines. Finally, we'll examine Wireless and Satellite based Internet access options in today's wrap up:
Wireless Internet Access
Wireless access works by transmitting and receiving radio waves between your location and the ISP's tower. When you sign up for Wireless Internet access, you will receive an antenna with an integrated radio, which must be installed outside on a pole or a mast, similar to a satellite dish. This connects via a "coax" cable to an external "modem" which you place near your computer. The modem has a basic ethernet port, which connects to an ethernet card inside your computer either directly via an ethernet cable or via an ethernet hub; much the same way that you would connect a DSL or cable modem. Once all the equipment is properly installed and configured, you will have a high-speed connection to the Internet, with a fixed IP address.
Wireless access is fast: providing a bi-directional 1Mbit (approximately 1000Kbit upload and download) connection with a download speed that is comparable to the peak download speed of DSL, but an upload speed that is nearly 8X that of DSL. For comparison, the best connection with a 56K modem is downloading at around 53Kbit and uploading at 33.6Kbit. Of course, your actual speeds will vary according to conditions on the Internet and the strength of the signal you are able to get at your location. Like DSL or cable access, Wireless access provides you with an "always on" Internet connection, so it is unnecessary to dial-up to the ISP's server; the moment you turn your computer on, you are online, and you don't need to buy any special new phone lines in order to do it.
Also like DSL, however, Wireless service is distance-limited: you must be located close enough to the ISP's base station to get a signal, or you won't be able to connect; if you are far away from the antenna, you may still be able to get a connection, but at a reduced speed. Also, it helps to have a direct line-of-sight to the antenna, but this is not absolutely required. In addition, because Wireless service does send signals through the air, it can be adversely affected by bad weather such as fog, rain, or snow, although testing has shown that the equipment usually works well even in the rain and snow. Finally, the initial cost of the equipment is typically higher than for other services, with basic hardware costs alone ranging from $900 to $1,300 or more.
Some of the cost is due to the fact that beyond the high equipment price, the radio antenna must be installed outdoors, so it may be necessary to hire a contractor to do the installation for you, and the contractor's fees would depend on the difficulty of the installation. But since Wireless access doesn't involve any intervention from any other companies, such as the phone company, there are no additional or hidden charges beyond the monthly charges, which start around $65 for residential service.
Satellite Internet Access
The last technology attempting to make it into the main-stream market is satellite Internet access. This is just what it sounds like: a system that uses satellites to beam down signals to your computer. As you can guess, this does not come cheap.
The biggest drawback with these 'consumer level' systems is that to make it affordable, you can only receive signals by satellite, not send them. That means you have to dial up using a modem to send the signals to tell the satellite what you want to see, and although a satellite may be capable of 1Mbps transfer, you are limited to 56k upload speeds. For comparison, to receive a 100K file at 1Mbps takes less than a second, but to send it still takes 18+ seconds. Combined with the expense of owning a satellite dish, it tends to be unaffordable compared to other access systems, but may not be a bad option in the absence of other forms of high speed 'Net access. Two-way satellite systems do exist, but access tends to run in the thousands of dollars per month and they're intended for business use.
Two-way satellite systems do exist, but access tends to run in the thousands of dollars per month and they're intended for business use. This is because the bandwidth useable by a satellite is more costly than the existing telephone and cable wiring infrastructure, or in other words, it is much harder to put a satellite in orbit than to run a wire into a house.
Lastly, like Wireless systems, satellite signals are interfered with by weather and other objects that can get between the dish and the satellite. Snow, ice storms, and heavy cloud cover can limit your ability to receive signals; even a plane passing overhead can interrupt a data transfer long enough to cause it to fail.
So Which Is Best?
Each system has it's own advantages and disadvantages. I believe that cable modem access is the best buy at the moment because it's becoming available everywhere quickly, and doesn't slow down as fast as DSL does when more people join. Although the cable and telephone companies won't admit it, broadband data transfer methods are inherently flawed in this capacity: as more people use these systems, they use more bandwidth, and begin to jam up and slow down with the added traffic.
With ADSL's quirkiness, it's also hard to justify spending the extra money each month unless you live beside a Central Office, but with new formats of DSL being invented, eventually the access distance limitations may decrease, and DSL remains unavailable in many areas because the speeds drop below dial-up capacity.
Wireless access can provide blazing speeds in remote areas (under the right circumstances), but its current availability isn't widespread. Satellite Internet access is a great idea, except for its expense, and in order to become viable as an Internet subscription method, two-way satellite systems must come down to reasonable prices; otherwise they're nothing more than a fancy toy.
For those of us in areas that aren't serviced by cable and DSL, dial-up access will continue to be our primary method of connection. At least until better Wireless services become nationally available that is...