Blog // Connect Minnesota
Broadband Internet Access Basics
Contributor: John Determan
We talk a lot about broadband and bringing it to more homes, businesses, and communities across the nation. But do you know the different delivery methods for making that access and adoption possible? If not, don't worry. You're not alone.
DSL, Wi-Fi, and Cable are terms that might look a little strange to someone who isn't paying close attention. Want to know the differences between broadband delivery methods? The following is a list of the major broadband delivery methods and how they work:
- Cable. In the mid 1990’s cable TV operators began upgrading their equipment to support new technologies such as VoIP and high speed Internet access. Broadband cable Internet access requires a cable modem at the customer's premises and a cable modem termination system at a cable operator facility, typically a cable television head end. The two are connected via coaxial cable or a Hybrid Fiber Coaxial (HFC) plant. Cable modems use a range of frequencies originally intended to carry RF television channels. Cable services generally support between 1 and 30 Mbps of network bandwidth, though some urban areas are now receiving up to 100 Mbps.
- DSL (Digital Subscriber Line). DSL is a technology that provides Internet access by transmitting digital data over the wires of a local telephone network. On the customer premises, a DSL filter on each outlet removes the high frequency interference, to enable simultaneous use of the telephone and data. DSL is generally limited to a distance of 15,000 feet from the telephone company’s central office or remote DSLAM (short for Digital Subscriber Line Access Multiplexer). DSL services generally support between .5 and 15 Mbps of network bandwidth.
- Fiber. An optical fiber is a flexible, transparent fiber made of a pure glass not much thicker than a human hair. It functions as a waveguide, or “light pipe” to transmit light between the two ends of the fiber. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fiber services are generally offered at speeds anywhere from 1.5 Mbps up to 150 Mbps of network bandwidth. As of mid 2011, Verizon and AT&T had built out fiber to 50% of their national service areas. In 2011 Google began construction of a 1 Gbps fiber optic network in Kansas City.
- Fixed Wireless. Fixed wireless travels “over the air” on frequencies authorized by the Federal Communications Commission. Signals are broadcast from a transmit radio (Access Point, AP) and is received by equipment located at your home known as CPE (Customer Premise Equipment) that includes an antenna and a radio. Fixed wireless providers (a.k.a. Wireless ISPs, or WISPs) use tall structures such as towers, water tanks, grain elevators and rooftops, typically located on high elevation points, to broadcast their data service in a wide coverage area. Fixed wireless services generally support between 1 and 10 Mbps of network bandwidth.
Wi-Fi is, perhaps, the most commonly recognized and widely used form of fixed wireless service. Wi-Fi transmitters cover much smaller areas and generally offer slower bandwidth.
- Mobile Broadband. Air cards, SIM cards, “my-fi” devices, and “Wi-Fi” cards are used to receive mobile broadband. Mobile wireless Internet access makes email access and Web searching possible at residences that have no DSL, cable, or fixed wireless alternatives. Mobile wireless is typically offered at throughput rates between .6 and “up to” 7.2 Mbps of network bandwidth and often carries a bandwidth “cap”. Mobile carriers such as Sprint, AT&T, Verizon (and others) have recently started to upgrade their 3G networks or are in the process of adding 4G LTE, which may ultimately be capable of speeds reaching 100 Mbps.
- Satellite. Compared to other forms of wireless Internet service, satellite enjoys the advantage of availability. Requiring only a small dish antenna, satellite modem and subscription plan, satellite works in almost all rural areas not serviced by other technologies. However, satellite also offers relatively low performing wireless Internet. Satellite may experience high latency (delay) connections due to the long distance signals must travel between Earth and the orbiting stations. Satellite also supports relatively modest amounts of network bandwidth. Satellite Internet service is sold to remote users in the U.S. by providers. These companies offer plans with download rates between 1 to 2 Mbps. Viasat recently launched a new service called Exede, which offers speeds of up to 12 Mbps (subject to certain bandwidth caps).
These delivery methods are the tools by which broadband can be brought to more areas across our state. Our dedicated team works with local providers and governments to map the availability of these delivery methods and the best plans for bringing more options to more communities. Stay-tuned tomorrow when we talk about how we go about validating these platforms, testing their effectiveness and ensuring that we are utilizing the best possible broadband maps to ascertain where there is still work to be done to bridge the digital divide.