While cellular coverage is available almost everywhere, internet access via cable and fiber serves only those areas where providers can make money, which doesn’t include great stretches of the country where communities are small and homes are widely spaced. Here, choices range from DSL (assuming the customer is close enough to a telephone central office) and dial-up at a blistering 56 kb/s. If that seems unlikely, as of 2015, AOL still had more than two million subscribers to its dial-up service and the customer base is fairly steady. Even though DSL has advanced considerably since it first emerged in the 1990s, the highest possible download data rate from any commonly-available version of DSL is about 6 Mb/s, and that’s in ideal cases, of which there are few.
WISPs: The Fixed Wireless Alternative
Wireless Internet Service Providers (WISPs)—an alternative that most people probably haven’t heard of—serve areas that no other companies want to (Figure 1). There are around 2,000 of these companies, mostly small and serving a few communities, but some have several hundred thousand customers. Collectively, they serve about four million people primarily in rural areas but also in urban areas where they provide backup data service for businesses and fill in the gaps in cable and fiber coverage (Figure 2).
A WISP is categorized as a fixed wireless access (FWA) or broadband wireless access (BWA) “last mile” service, in the more basic sense transmitting and receiving signals from a single point to multiple locations—point to multi-point (PMP). Some WISPs still use Wi-Fi (much advanced today) although others use proprietary protocols such as Motorola’s Canopy and continue to operate in unlicensed spectrums between 900 MHz and 5 GHz. Communications between base stations are conducted using point-to-point microwave radios at very high data rates. Every linked tower adds another potential service area.
Obviously, even the largest WISPs have a tiny fraction of the resources of a major telecom company, so their goal is to cover as many subscribers as possible with the best possible service using the least infrastructure. This requires the use of technologies like Multiple Input Multiple Output (MIMO), dense encoding streams that pack more data into a given bandwidth and, soon, versions of LTE sans its features for mobile communications. LTE has the considerable advantage of being a highly-proven, advanced and modern wireless access method that is extremely robust.
Another technology helping WISPs serve more and more customers with higher throughput is the use of sectored antennas (Figure 3), the same way cellular carriers do by separating coverage areas into sections, each one served by a radio and antenna, which allows more available bandwidth to be accessible by each customer. To understand this, consider a WISP system that has 30 MHz of channel bandwidth and 100 subscribers.
If it used an omni-directional antenna on the tower, all 100 customers would be sharing the bandwidth. However, by “reusing” this bandwidth in each sector (three for example), each sector would serve only 33 customers and each one would have the full 30 MHz. The result: much higher throughput as speed can increase only if there is bandwidth to support it. MIMO is also a major contributor as well, as it adds to the system’s capabilities by dramatically optimizing performance as it also does in Wi-Fi and increasingly cellular systems.
How WISPs Began
The history of the WISP industry reads a lot like how the West was won. Back in the late 1990s, to access the internet, the choices were either DSL, dial-up, or, less frequently, CCC. In rural areas, there was either dial-up or nothing. This rapidly became less and less tolerable in these remote places, so various groups of enterprising, technically-adept people decided to use the newly-minted wireless technology based on the IEEE 802.11 standard: Wi-Fi. Their goal was often to provide internet access to themselves and their neighbors.
This DIY approach consisted of finding a high point in town, a tower or anything else with a reasonable height above average terrain. To this point, they ran whatever wired data-capable medium technology was available and connected it to a Wi-Fi transceiver and high-gain directional antenna on the tower (or whatever) that was pointed toward their homes. At the “subscriber” site, another directional, high-gain antenna was mounted on the roof or any other high structure on the property. The output was then connected to a computer inside the home. With this, it was possible to achieve download speeds of perhaps 1.5 Mb/s. While not very fast and sometimes not terribly consistent, it was a lot better than dial-up—or nothing.
Of course, as soon as word got out, everyone wanted it, so these fixed wireless access pioneers found themselves in the telecom business providing a community service. LARIAT, a non-profit rural telecommunications cooperative founded in 1992 in Laramie, WY, and operational since 2003 may be the first organization in the U.S. although other groups beg to differ. LARIAT originally used NCR WaveLAN equipment operating in the unlicensed 900 MHz Industrial Scientific and Medical (ISM) band.
WaveLAN, developed by Lucent Technologies, exploited the technology with the IEEE 802.11 standard and could achieve downlink speeds of about 1.1 Mb/s over about 70 ft. LARIAT is still in operation and still serving Laramie as LARIAT.NET, and takes pride in its status as a “locally-owned, locally-operated, locally-managed non-franchise operation." It offers a basic package of data VoIP phone service for $30 a month and more inclusive, higher speed service for a little more.
WISPs Today…and the Future
The story thus portrayed may seem like WISPs are “better than nothing," but this is selling them short. Most WISPs can deliver reliable download speed of 15 Mb/s and, depending on a variety of circumstances and the particular provider, can reach 100 Mb/s and some even as high as 1 Gb/s. The radios they use are far from simple, combining Wi-Fi and TDMA or proprietary access methods, upward scaling, optimized frequency reuse with integrated GPS synchronization, Gigabit Ethernet, up to 8x8 MIMO (and increasing) and dynamic spectrum management. They can typically achieve data rates up to 1.5 Gb/s to the user and can serve up to 100 subscribers. All this is integrated within an enclosure the size of a book.
As for their future, WISPs seem relatively comfortable in their position as competition consisting of other WISPs and the expansion of fiber into more areas by traditional cable and telephone companies. However, fiber is very expensive to deploy and won’t likely be a factor unless a community becomes large enough to make it profitable. In some areas, this may not happen for many years. Consequently, they are likely to remain the only economically viable way to deliver broadband data and voice service into rural areas, as they can even operate in places where population densities are only a few subscribers per square mile.