Because, the possibilities are endless. Wireless is the bridge between the performance of fiber and the affordability of DSL or cable. Depending on implementation, wireless service can replace wired networks, including internet, telephone, and video. Wired service providers must obtain permits and easements, and they must excavate and install the copper wire, or fiber. This is very expensive, and the costs get passed on to you. Wireless services ARE the future. There are a world of resources stating this (CNET Computer.org, Internet.com all agree). Wireless is the bridge between the performance of fiber and the affordability of DSL or cable (see comparison). A wireless service provider can reach outlying areas where the traditional wired systems do not reach, and reach it instantly, where a wired service can take months to be installed.
Copper (phone lines/T1/DS3 etc) is old technology. For 'Last Mile' service (the last leg in the chain i.e. from you to your isp) copper lines used to be the only game in town. All that has changed now. Telephone companies, which own all the wire (and more importantly the easements and right-of-ways) had a monopoly on the market. While some companies may lease these lines in bulk, the local telephone company ultimately controls and profits from their huge investment. These lines must be maintained. Problems ranging from accidental dig ups (or the 'backhoe virus' as the industry calls it) to rodents and insects destroying cables and splice enclosures, and environmental influences (earthquakes, 'Ice Storms', normal winter freeze/thaw and high wind) telephone companies must expend vast resources to maintain their lines. These resources must be reclaimed, on your bill. more
The nature of the cables which hold many pairs (2 wires are required for every connection) is simply a bundle of wires. Interference and cross-talk (interference caused by the signal on any of the other pairs in the same bundle) violate the clear transmission of voice/data on these wires. This causes a scratchy or muffled sound on analog (voice) data and data errors on digital (data) signals. The net result of this is that there are limitations to the quality and amount of signal which can be accurately transmitted. The noticeable affect of this hindrance with regards to data, is slower connections both on modem and on DSL as well as dropped connections. More dramatic problems are observed by individuals attempting to use telephone services which are located at greater ranged from the CO (telephones central office). People in outlying areas often report having terrible voice quality (including being able to hear conversations of their neighbors, a clear sign of cross-talk) and only connecting at 14.4 kbps or even not at all from their modems. Telephone companies use a technique called multiplexing to get more efficient use of their physical lines.
Multiplexing essentially can compress up to 24 simultaneous voice signals, digitize that information and cram it down one pair. This is very cost effective as they don't have to run new lines constantly. This compressed line is referred to as a T1. Many T1s can be multiplexed into a T3 (or DS3) which yields up to 45mbps data rates. A side affect of this is that when digital data is transferred to analog, by a modem, then digitized by the multiplexor, and possibly several more conversions as the signal propagates from one CO to another, and finally to an ISP, the signal is so degraded that a 56kbps modem might only get 28.8 or less. This coupled with long distance from the initial CO can render internet use with a modem virtually impossible.
DSL is a high bandwidth implementation of these same phone lines. DSL uses high frequency signals that are barely audible to attain much higher data transfer speeds. This high frequency signal cannot be multiplexed and hence there is a limitation of service. The signal can only travel barely over a mile before the interference destroys the signal. You must be located within less than 2 miles of your local CO (see references). This is an eliminating factor for individuals in outlying areas. Even if someone is within that 2 mile radius, the line must be tested for compliance. Many lines fail due to faulty wiring somewhere in the ground or overhead between the CO and the end user's location. The different technologies available as xDSL where x is A (for asymmetric) or S (for symmetrical) are the most popular of the different services. aDSL is by far the more popular and the more inexpensive of the other options.
Another option available from the telephone company is a dedicated data line. These are available in 64kbps increments all the way up to 1.544. This is a very costly endeavor. Typically there are two entities: the telephone company, and the backbone company. In this model the telephone company 'back hauls' (a term meaning bringing the backbone company's signal the distance between their location and that of ISP) which is also referred to as 'middle mile' service. The telephone company may act as the ISP or provide service to the ISP, providing 'last mile' service. One benefit of the telephone running a T1 (or greater) is that the 24 slots can be filled with data (at 64kbps cumulatively per slot) or voice service. The drawbacks are mainly cost and availability. Installation may cost many thousands of dollars and may take months. Cost per month may also be a thousand or more dollars per month. This line is also susceptible to interference and the same problems listed above. This expense is further augmented by the requirement of a router (a required device which lets computers connect to a T1) and a CSU/DSU (basically a T1 modem). These alone can cost many thousands of dollars.
Cable is referred to in this dissertation. as the internet service provided by a Cable TV company. Increased downstream bandwidth can be attained by this technology. Typically up to 2mbps is shared with up to 684 clients. Most users will see a definite improvement over a modem. Uploads however, are very limited. A maximum of 128kbps is shared between the same pool of users. This system is very insecure. Anyone with a special program called a packet sniffer, can watch an individuals activity and capture non-encrypted passwords, credit card numbers and other personal information. Cable also shares the same drawbacks as Copper wire with regards to reliability.
As with Copper lines Cable Companies must also obtain property rights to run their cable. This coupled with the maintenance expense requires the cable companies to expend vast resources as well. Since cable TV companies do not provide essential services (as telephone companies do) they typically have a slower response time to trouble on the line. Cable Internet is not a viable solution for businesses.
Fiber is far superior to the other options. Fiber can carry essentially unlimited bandwidth. Latency (the time required to get data from point A to point B) is incredibly low. Fiber optic lines carry huge amounts of data over extremely long distances and constitute a large share of all internet backbone. It can bring all the services one would desire. HDTV video signal, ultra high quality voice telephony, video telephony, and broadband data are all well within the capabilities of fiber. The only drawbacks are cost and reliability. Fiber optic lines share the same requirements as Copper. Easements and right-of-ways must be obtained. Installation is an expensive endeavor. The equipment on either side of the fiber line, while able to handle a huge amount of traffic, is incredibly expensive, in the millions. Interruption of signal is likely due to environmental obstacles and accidental dig ups. The solution to this problem is running multiple lines in separate physical spaces for redundancy. This increases cost. Availability is extremely limited. Installation is very expensive. As a 'last mile' solution, fiber will not be a viable option for many years. In the distant future, it is conceivable that fiber optic lines could replace copper lines in both commercial and residential environments.
As a backbone transport and even a 'middle mile' solution fiber is very attractive. Fiber is very secure. It is very difficult to intercept data on an optical fiber without being detected by the equipment on either side. This equipment is so well calibrated, it can pinpoint breaks or other problems within a few hundred feet on a fiber hundreds of miles long. Response time is quite timely due to the fact that on most fiber networks, as these networks carry essential services.
While heralded as a fantastic solution, satellite internet service suffers from many problems. Firstly cost. It can cost between 40 million and 200 million dollars to launch a satellite (see references at lightcraft). This spread out between many users can be cost effective, however this limits the performance. The cost to the end user is relative to DSL.
In many implementations a phone line is required for uploads. Upload speed is important. IP (Internet Protocol) is a request/response arrangement. For an individual to see a web page or use any other service on the web, a request must be sent. The server in turn responds with the data. To view a web page, hundreds of request/response signals may be sent. If upload speed is slow, the resource requested will be delivered much slower.
Latency is the time it takes for a packet (the way data is sent on the internet, everything is in a packet or multiple packets) to get from source to destination. Latency times in the 200 millisecond range are typical for most internet connections. Satellite connections have a much longer latency. As much as 3000 millisecond (or 3 seconds) have routinely been observed. This means that to get something one packet in size from the internet, it could take up to 6 seconds. If the object (image or webpage or a piece of data used in a multiplayer game) consists of many packets, it could take much longer to complete the transaction. This renders satellite connection useless if an individual is playing a internet enabled multiplayer game, or video conferencing, for example.
The only exclusive advantage is availability. Satellite connections can reach virtually anywhere that has a clear view of the sky. All the continental United States and much of the rest of North America can get satellite internet service, even where no telephone lines exist. Many times satellite connections is the only option for those well beyond metropolitan areas.
The performance of wireless is extraordinary. Most noticeably the latency times. Transit times lower than 3 milliseconds (0.03 seconds) are typical. Average ping (response) times are 1 millisecond. Bandwidth is also very exceptional. The current technology allows for 11mbps. Speeds in the 45mbps range will be possible by the end of 2001. As with all technology, improper implementation can destroy performance. Many implementations make use of Frequency Hopping methodology. This limits maximum network bandwidth to 1.4mbps. There are cost advantages to this type of hardware but at the sacrifice of performance and scalability. Direct Sequence Spread Spectrum implementations which follow the IEEE 802.11b specification, are portable, optimized, high performance. Security is also a factor. Early products had problems with the rotating algorithm that generates the encryption key. More recent products such as Lucent's Orinoco and Enterasys products have resolved this issue. These modern systems are extremely reliable.
As stated earlier, implementation is key. Proper planning prevents dead spots and signal degradation. Effective distribution is quintessential. Ranges to 30 miles are possible with high quality amplifiers and antennas. If towers are located well and are distributed evenly, an entire city can receive fantastic service, with no interruption of service.
Users of wireless ISPs should see a remarkably lower cost than that of other competitive services. Costs can be minimized further with proper implementation. Residential customers could see rates comparable with DSL and commercial users should expect rates much lower than T1/Fractional T1.