Types of Internet Access
There are many technologies available to access and connect to the Internet. Each has its advantages and limitations, with price and availability being common limiting factors.
Internet Dial-up Modems
A 56 Kbps (kilobits per second) modem is a good starting point for Internet Access and lower end applications, especially those homes or businesses on a modest budget. This is dial-up service. Each user needs their own modem and phone line to dial-up and connect to the Internet. A jack with a phone line must be located near the computer. The modem ties up the phone line so the phone can't be used when the computer is online, and vice-versa. If you wish to use multiple devices simultaneously, you should consider another technology.
Modem technology can be expensive if there are many users, due to the cost of separate phone lines and modem for each user. One way to solve this problem is to install a modem on a server computer and use software that enables your users to access the modem as a shared device. The downside to this is that only one network can access the Internet at the same time, and performance is compromised due to the limitations of this set-up. Another alternative to share modems on the network is by setting up a separate computer to function as the communications server. One or more modems can then be installed in the communications server computer so that the network users can access the modems. This will require special software to be installed.
Cable Internet Access
Cable modem service is offered by cable TV operators and provides broadband access using the same coaxial cables that deliver pictures and sound to your TV set. Cable modems are external devices, with two connections - one to the cable wall outlet and the other to your computer. Cable modems can provide transmission speeds of 1.5 Mbps (megabits per second), or more. You can watch cable TV and surf the Internet simultaneously with a cable modem. Transmission speeds will vary depending on the type of cable modem, cable network, and traffic load.
Cable internet access is "always-on", and is generally better suited for home use rather than business purposes. Due to the current limitations of cable technology, it is usually not a viable solution for businesses. These limitations include the wiring, as most businesses are not wired for cable, congestion and delay. The service slows with multiple users online. However, a cable Internet connection is much faster than a dial-up connection.
Fiber Optic Services
Fiber optic technology carries data by converting the data to light electrical signals, then sends the light through transparent glass fibers about the diameter of a human hair. Fiber transmits data at speeds much faster than current DSL or cable modem speeds, usually by tens or even hundreds of Mbps. The actual speed, however, will vary depending upon a variety of factors, such as how close to your computer the service provider brings the fiber and how the service provider configures the service, including the amount of bandwidth used. The same fiber providing your broadband can also simultaneously deliver Voice over Internet Protocol (VoIP) and video services, including video-on-demand (VOD).
Some network operators (usually telephone companies) are offering fiber-based broadband in limited areas, expanding their fiber optic networks, and providing bundled voice, Internet access, and video services.
Primary Rate Integrated Services Digital Network (PRI ISDN) Services
You can use PRI ISDN to both access the Internet and connect your network to the Internet. It is a dial-up service that does not require a modem and it's substantially faster than "regular" modem service. PRI ISDN has 23 B channels plus one 64 Kbps D channel. Each channel has a capacity of 64Kbps, enabling a total transmission speed of up to 1.536 Mbps. You can split the line into separate channels, thus enabling multiple users to talk on the phone and access the Internet at the same time. A working speed of 64 Kbps is possible for each user.
Digital Subscriber Line Internet Access (DSL)
DSL is a good option for homes and small businesses to access the Internet. This technology is easily installed and affordable. This high-speed service is "always-on", and you access the Internet over ordinary phone lines.
You will need a DSL modem and an Ethernet card, and a splitter may be required. A splitter is a frequency filter that separates the high frequencies used for sending data upstream and receiving downstream data from the low frequency range used for voice. These high and low frequencies are transmitted simultaneously, so you can talk on the phone access the Internet at the same time.
T-1
T-1 is a leased Internet Access service and network-connect technology that is best suited for large networks where 20 or more users are accessing the Internet at the same time. T-1 is nearly ten times as fast as ISDN and has speeds to around 1.54 Mbps. Up to 24 users can use the service simultaneously with each using 64 Kbps. This service is "always-on". T-1 can be used to connect a Private Branch Exchange (PBX) to the telephone company's central office (CO). T-1 is often used to connect remote LANs (Local Area Networks).
Fractional T-1
You can lease a portion of a T-1 line if your business does not have 20 or more users. This will keep your expenses down, while giving you a premium service for accessing and connecting your network to the Internet.
T-3
T-3 is a high-end leased service used by many medium-to-large sized organizations for accessing the Internet and connecting a network to it. A T-3 line can transmit data at speeds around 44 Mbps. It is equal to 28 T-1 lines. Up to 672 users can use the service simultaneously while working at 64 Kbps. T-3 is an excellent solution for businesses with large calling volumes (i.e., calling centers). This service is "always-on". T-3 can be used to connect a Private Branch Exchange (PBX) to the telephone company's central office (CO). T-3 is also used to link remote LANs.
Fractional T-3
If your business doesn't need the full T-3 line, you can lease a portion of it. This will keep your expenses down, allows simultaneous access to many users, while giving you a premium service for accessing and connecting your network to the Internet.
Frame Relay
Frame Relay is used for large-scale applications requiring accessing the Internet and interconnecting LANs. It is also used to connect LANs to WANs (Wide Area Networks). Frame Relay data rates range from 56 Kbps to 45 Mbps, which allows you a wide range of flexible options to choose from for your business needs. This service is "always-on".
If your LAN Internet usage greatly varies throughout the day, and you send data in bursts, Frame Relay may be the best solution for you. With Frame Relay Internet access, you can utilize your Internet connectivity at key times throughout the day by "bursting" up to the full limit of the transport. A burst is a specific amount of data sent or received in one sporadic operation. Bursty data uses bandwidth intermittently, and does not use the total bandwidth of a circuit 100 percent of the time.
Wireless
Wireless broadband can be mobile or fixed. Wireless fidelity (WiFi) is a fixed, short range technology that is often used in conjunction with DSL or cable modem service to connect devices within a home or business to the Internet. WiFi connects a home or business to the Internet using a radio link between your location and the service provider's facility. This fixed wireless broadband service is becoming widely available at airports, city parks, bookstores, and other public locations. These locations are known as "hotspots."
Fixed wireless technologies using longer range directional equipment provides broadband service in remote or sparsely populated areas where other types of broadband would be too cost prohibitive to provide. Speeds are comparable to DSL and cable modem service. Generally, an external antenna is required. With newer services now being deployed, such as WiMax, a small antenna located inside a home near a window will usually suffice, making higher speeds possible.
Mobile wireless broadband services, such as 3G, are available from mobile telephone service providers, and others. These services generally require a special card with a built in antenna that plugs into your laptop computer. Generally, they provide lower speeds, somewhere in the range of several hundred kbps.
Satellite
Satellite broadband is a form of wireless broadband that is particularly useful for serving remote or sparsely populated areas. Downstream and upstream speeds for satellite broadband depend on several factors, including the provider and service package purchased, your line of sight to the orbiting satellite, and the weather. Satellite service may be disrupted in extreme weather conditions. Typically, you can expect to receive (download) at a speed of about 1 Mbps and send (upload) at a speed of about 200 kbps. These speeds may be slower than DSL and cable modems, but the download speed is still much faster than the download speed of dial-up modem Internet access.
Obtaining satellite broadband may be more costly and involved than DSL or cable modem. You must have:
1. A two or three foot dish or base station, which is the most costly item
2. A satellite Internet modem 3. A clear line of sight to the provider's satellite
Broadband over Powerline (BPL)
BPL delivers broadband over the existing low and medium voltage electric power distribution network. BPL speeds are comparable to DSL and cable modem speeds. BPL is provided to homes using existing electrical connections and outlets. BPL is an emerging technology, available in very limited areas at this time. Because power lines are installed virtually everywhere, the potential is significant as it alleviates the need to build new broadband facilities to every customer.
