Bowling Green, KY (January 2, 2020) – There are several types of broadband delivery methods, or “broadband platforms,” across the U.S. The type of broadband available in any given area, in any state, can depend on several factors:
- Is the population dense or sparse?
- What’s the return on investment (ROI) for the technology type?
- Are homes located several miles apart or close together?
- Are there pine trees or heavy foliation around the region, or is the terrain flat and bare?
- Who is the competition, and what do they offer?
I can speak from experience when I say that fixed wireless is one of the most misunderstood technology platforms. It can be delivered using licensed or unlicensed spectrum, it comes in a variety of frequencies, it can serve a single point or multiple points, you can’t have Wi-Fi without it, but it’s much more than just Wi-Fi. It’s quick and cost-effective to deploy, equipment is now widely available, and it’s a great option for delivering broadband service to rural America. Soon, we’ll be discussing whether 5G is coming to a town near you (or not), but for now, let’s stick with the basics.
Broadband Platform Overview
In the mid-1990s, 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 using what is known as “Data Over Cable Service Interface Specification” (DOCSIS). First created in March of 1997, the DOCSIS standard has undergone numerous iterations over the years. Today, DOCSIS cable services generally support from 1.2 Gbps (DOCSIS 3) up to speeds of 10 Gbps. Cable companies generally offer slower packages of service, however, such as 100 Mbps, since many consumers don’t have a need for advanced bandwidth.
DSL (Digital Subscriber Line)
DSL is a technology that provides internet access by transmitting digital data over the copper 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 wire-feet from the telephone company’s central office or remote DSLAM (short for Digital Subscriber Line Access Multiplexer). Wire-feet are the distance the copper wire actually travels from the DSLAM to the home (not “as the crow flies”). The length of the phone line between the residence and the phone company hub affects speeds; in other words DSL is distance sensitive because its performance decreases as you get farther from the DSLAM. DSL services come in different formats and, as such, offer different speeds. Most DSL technologies use asymmetrical data transfer, which means consumer download speeds will be much faster than their upload speeds. Today, depending on where you live, speeds could range from 1 Mbps up to 100 Mbps.
An optical fiber is a flexible, transparent conductor made of 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 optic strand. Optical fibers are widely used in network communication designs, which permits transmission over longer distances and at very high data rates. Fiber optic service speed can vary, depending on how the “last mile” of service enters your home. Last mile is truly more like the last feet, but the delivery type makes a big difference. If the fiber optic cable ends at a node, the last mile can be delivered over copper, coaxial, ethernet, etc. and is referred to as “fiber-to-the-node” or FTTN, whereas if the fiber terminates inside the home itself it is referred to as “fiber-to-the-home” or FTTH. Some companies also refer to the latter as “fiber-to-the-premise” or FTTP. The last mile delivery impacts your speed (see discussion above regarding hybrid fiber coaxial) which is generally offered at speeds anywhere from 1 Mbps up to 10 Gbps.
Fixed wireless travels “over the air” on frequencies authorized by the Federal Communications Commission. Signals are broadcast from a transmit radio (transmitter and/or access point) 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 100 Mbps of network bandwidth.
Today, however, gigabit services can be delivered over millimeter wave frequencies, albeit limited to distance of less than ½ mile under normal conditions. This will be discussed in an upcoming blog related to 5G (5thgeneration) fixed wireless and why it will not solve the digital divide problems in rural America.
Air cards, SIM cards, “my-fi” devices, and “Wi-Fi” cards are also 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 comparable to DSL or DOCSIS networks but often carries a bandwidth “cap” (a limitation of the amount of data you can use during a typical 30-day billing cycle). Mobile carriers such as AT&T, Sprint, T-Mobile, Verizon (and others) may still operate 3G networks in rural markets, have upgraded to 4G LTE networks in their densely populated service areas, or are in the process of adding 5G layers, which may ultimately be capable of speeds reaching 1 Gbps or greater. Today, 5G has been limited to rollouts in the nation’s top markets (New York, Chicago, etc.) with notable success stories in large gathering areas such as MetLife Stadium (Verizon) and AT&T Stadium (guess who).
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 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 and service is sold to remote users in the U.S. by several providers. Viasat recently launched a new service called Exede that offers speeds of up to 12 Mbps (subject to certain bandwidth caps) across most of the U.S. but also offers higher speed levels to certain parts of the country. For example, my ZIP code in Eastern Kentucky indicates that I could receive “up to” 30 Mbps for a mere $100/month.
About the Author: Charles (Chip) Spann is the Director of Engineering & Technical Services. He leads the ETS team in discussions with broadband service providers on data collection and improvements, developing propagation models for wireless coverage, and providing engineering solutions for providers, communities, and states. He also oversees extensive field validation and mobile drive testing.
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