Friday, October 26, 2007
A look at options for Internet access in Carlisle
As the technology of internet connection options evolves at a rapid pace, Carlisle residents are always playing catch-up to get on board with the latest and greatest. There is no doubt this anticipation creates excitement in some and frustration in others.
Internet options come in several different flavors, including Dial-up, DSL, Cable, Satellite, T1, wireless hotspot and FIOS.
Although there are many differences with each of these options, the most crucial differentiator is the speed at which the data travels from one computer to the other. The speed is referred to as the transfer or data rate and is measured in thousands of bits per second, Kbps, or millions of bits per second, Mbps.
While often unnoticed by the user, the time it takes for data to reach your computer from a remote server, the "download time" is not necessarily the same as the "upload time" needed for information to flow in the reverse direction.
•Dial-up was the very first option that was easily available and is still actively used. Dial-up requires no additional hardware except for your computer, dial-up modem and phone line. This simplicity and low cost are positive attributes of this option. Due to the fact that it uses the analog phone line to establish communication with the network, the quality of the connection is not always good and data rates are limited in most cases to 56Kbps. Some choices with dial-up are NetZero and Earthlink.
•DSL (Digital Subscriber Line) links people to the Internet by sending high-speed signals through their existing telephone lines. According to a Verizon representative, DSL is not available in Carlisle. In those towns in which it is offered, customers must be located near a "central office" (CO), an area's phone-line gateway.
•Cable broadband technology is by far the most popular choice and the most common provider available in Carlisle is Comcast. A cable modem can provide both high-speed Internet and TV network access through the same wiring. Internet access is possible at speeds of about one million bits per second, or about 20 times faster then through dial-up modems. The upload and download speeds benchmarked from a Carlisle location were 1,329 Kbps and 4,377 Kbps respectively. Upgrades provide greater speed.
• Satellite technology is another viable option that can bring an always on Internet connection to places DSL and cable can not reach. The computer is connected to a satellite modem which is linked to a Satellite dish (antenna) typically mounted on the roof of the house. The satellite dish sends and receives information from the internet and sends information instantly. EarthLink, HughesNet and Wildblue are some providers who confirmed installation and service at Carlisle. Most of these options have comparable pricing and service models which include installation of the satellite dish with cabling (couple of hundred dollars) and a monthly service plan for Internet service.
One issue with satellite technology is the signal latency when a transmission is sent. The signal must travel 22,000 miles to the satellite orbiting the earth, and back down to the Internet service provider on earth, and the delay can be noticable in an application such as on-line games.
• T1 lines have a maximum speed of about 1.5 Megabits per second, although lower speeds can be purchased at reduced cost.
A working example of a T1 line is at the Gleason Public Library. Provided by the Merrimac Valley Library Consortium (MVLC), it provides the connection for the library's automated circulation and catalog system and the Internet for the staff. The current available speed is 384 Kbps and there is talk of upgrading that to 768 Kbps in the coming years. In addition to the T1 line, the library's public internet service is provided with a broadband cable connection through Comcast free of charge. The Carlisle School and Town Hall share another T1 line.
T1 can be an expensive option for residential use and this type of service is typically used by small- to medium-sized businesses as one can connect up to 200 computers with no loss of speed. The California-based company called Covad explained that the installation of a T1 line to a residence would include two new phone lines from the main pole to the customer's building. With a wireless router, it is possible to share the T1 line with neighbors for cost effectiveness. At a speed of 384 kbps the monthly rate on a three-year contract would be $350.
• Free wireless internet access is provided by Gleason Library to any patron who brings a laptop computer capable of receiving the signals. It is split from the public cable broadband internet service by means of a router inside the building. Library Director Angela Mollet notes that the wireless access can be also used by guest speakers because it extends to the Hollis Room on the third floor.
• FIOS (Fiber Optic Service) is the latest in high-speed internet technology. According to Verizon, which is marketing the technology, FIOS users will be able to see upload transmission speeds of 5 Mbps and download speeds approaching 30 Mbps. It delivers laser-generated pulses of light, riding on hair-thin strands of glass fiber. It is available nearby in Acton and Concord, but is not yet offered in Carlisle.
© 2007 The