Tech Primer: What you need to know about fixed wireless broadband

As we’ve seen, fixed wireless technology - in either point-to-point or point-to-multipoint applications - can support a variety of services, including voice data and video, as well as deployments at indoor and outdoor locations.

Those deployments can support a wide array of applications, including some quick wins we explored previously in areas such as government, transportation/traffic management, education and more.
Now, let’s take a step back and walk through a checklist of what you need to know to successfully deploy fixed wireless broadband technology in support of such applications.

Fixed Wireless Basics
At the most basic level, fixed wireless broadband is a type of high-speed network that uses radio signals rather than physical cables to deliver broadband service. Operators use fixed wireless to serve both residential and business customers, depending on their requirements. Fixed wireless is often used in areas where wireline coverage is either difficult or uneconomical to deploy.

The network equipment required to deploy fixed wireless is fairly straightforward as well: fixed ground stations or transmission towers that serve as the core of the network and transceivers installed at customer sites to communicate with the core network. Such links have traditionally required line-of-sight access – ie, no obstructions between them – to work most effectively, but technology improvements mean that today’s fixed networks can support no-line-of-sight as well. Today’s fixed wireless networks support high-bandwidth, low-latency transmission, meaning that the networks cannot only support “bursty” Internet access but more real-time data applications as well, including online gaming or voice over IP service.

In sum, fixed wireless broadband systems typically offer a number of advantages over wireline deployments, including simple network design and infrastructure, enabling rapid deployment (and tear-down, if necessary) and limited infrastructure, which makes it easier to deploy in hard-to-reach areas, such as urban environments or remote areas with inhospitable terrain.

The Spectrum Question
One of the big advantages of fixed wireless broadband technology is that it doesn’t require operators to acquire expensive licensed spectrum in order to operate. The recent 700 Mhz auction by the U.S. government resulted in winning bids reached almost $10 billion. That puts licensed spectrum out of reach for smaller operators. The economics of emerging WiMax systems also tend to favor larger carriers and larger deployments.

Today’s fixed wireless broadband platforms operate in a variety of spectrum slices (including 900MHz, 1.8 MHz, 2.4 MHz and 5 GHz.  With unlicensed spectrum, interference is always an issue. The key for operators is to, one, do careful upfront spectral testing and network design work to get a firm grip on interference issues; and, two, choose – and in some cases even mix and match – the right spectrum for their particular location and supported applications.

Choosing the Right Architecture
Fixed wireless broadband deployments come in a variety of flavors to support different solution requirements. The three most common approaches are point-to-point, point-to-multipoint and mesh

• Point-to-Point – If you are looking to replace a single leased line network – such as for transmitting traffic between two enterprise locations or backhauling for a cell tower location – a point-to-point architecture is the right approach. A point-to-point topology, thanks to its simplicity, offers the highest throughput over the longest distances. But connect more than a few sites in a point-to-point fashion and costs quickly rise and the individual links become more complex to manage.
• Point-to-Multipoint – If point-to-point won’t work for you, consider deploying the network in point-to-multipoint topology. Such networks connect multiple sites from a central location using an omnidirectional antenna that sends a signal out equally to all end points on the network. You make a bit of a sacrifice in distance, in particular, but gain cost savings and decrease complexity when connecting multiple sites.
• Mesh – Another approach is to deploy a mesh network, in which every radio can transmit signals to every other radio on the network. The benefit of such an approach is improved reliability and coverage; the downside is increased cost – at times for less throughput performance – versus less complex point-to-point approaches.

Fixed Wireless Advances
At this point, fixed wireless broadband is a very mature technology deployed in thousands of installations around the globe. Vendors have introduced an array of advances in areas including network design, security and quality of service assurances to make fixed wireless technology a strong alternative to wired solutions for a variety of applications, from simple wireless ISPs to enterprise point-to-point leased line replacement to specialty applications like video surveillance.

And advances keep improving the performance of the technology. For instance, solutions such as Motorola’s Canopy platform use orthogonal frequency division multiplex (OFDM) technology to enable wireless deployment to penetrate or go around foliage or buildings and other obstructions.  Another advance, GPS synchronization, use GPS time stamps to better coordinate signal transmissions and reduce errors.

With such improvements in the core technology, and a wide array of platforms and approaches to choose from, service providers should feel comfortable opportunistically selecting and deploying fixed wireless broadband for a variety of network approaches and applications.