White spaces wireless technology has been in the news recently, as what used to be TV frequencies are being opened up to expand wireless internet access to rural areas in the US and the UK.
But it's outside the developed world that this technology is having the most impact, as a recent conversation with Dondi Mapa, Microsoft's national technology officer for the Philippines, revealed.
White spaces technologies aren't new - they were something I looked into when working with the local loop group of a telecoms research lab back in the early 1990s. The system that Mapa is using in the Philippines is based on research from a Cambridge-based consortium that Microsoft Research, the BBC, and Sky began seven or so years ago.
"I'm always on lookout for technologies from Microsoft that could be beneficial to countries like mine", Mapa told ZDNet.
Disaster relief in the Philippines
Broadband penetration in the Philippines is low, especially outside the main population centres. So in 2012, as part of a government project, Microsoft began deploying a white spaces network on Bohol, an island in the central Philippines.
It's an important scientific site, with high bio-diversity, thanks to its double barrier reef. Protecting the reef means changing how people in coastal villages live, removing fishing boats from the water while still providing sustainable economic growth by deploying white spaces radios in fishing communities.
Early in the trial Bohol was hit by a series of natural disasters: first a magnitude 7.2 earthquake and then, just a few weeks later, Supertyphoon Haiyan. Just as the island struggled to rebuild its infrastructure, it was knocked back down again, with cities destroyed by storm surges and with transport and communications cut off.
That's where the white spaces technology came into its own, as it let Microsoft work with the government to quickly deploy an alternative communications infrastructure for devastated rural areas.
While there were satphones and VSAT deployments in some areas, people would need to go to where the satphones or base stations were - something that was very difficult given the condition of the island's roads.
At one evacuation centre, a single satphone had a queue of over 300 people waiting for three minute call slots. Many of those waiting had to come back the next day for their turn, and the journey was often several hours long and hazardous, requiring them to traverse debris-strewn roads with little or no transport.
Fortunately, white spaces equipment already existed on the island, and the Microsoft team worked with government partners to redeploy some of the radios in the rest of the island.
White spaces base stations were deployed alongside VSAT systems, with endpoints anything up to a couple of kilometres away, with wi-fi access points. That meant users didn't need to walk to VSAT terminals, and they could use their own devices, as the system was compatible with anything that could use wi-fi, including smartphones and tablets.
Deployment was quick, the network was up and running in two hours as it had an existing VSAT terminal to work with. With the power grid still out of action, the whole system was able to run off solar panels and batteries, including the endpoint white space radio equipment. The same panels could be used to charge smartphones and tablets as well.
An advantage of using white spaces technologies is that one base station can work with many endpoints; it's inherently a multipoint technology with a 90-degree beam pattern. You can locate endpoint radios anywhere in the beam and it'll work. That's a lot easier than working with traditional point-to-point radios, where aligning radio beams over a 2km path can take half a day.
Six weeks after the typhoon, Philippines telecoms companies were able to start re-establishing their networks, putting power into towers and replacing VSAT with fibre. All the while, though, they still used white spaces radios as last mile connectivity.
With services back in place, the project team was able to refocus its attention on Bohol's fishing villages, completing network rollout in April 2014, and starting to use the network to link the Philippines fisheries authorities with fishermen. This allowed the fishermen to use mobile devices, rather than having to travel to district offices, which took a lot of time and led to missed opportunities.
At the same time government officials could be more mobile. This allowed them to improve education and even medical facilities, as specialist devices allowed villages to work with central hospitals to offer remote diagnostic services.
A second phase of the network rollout is planned, to deliver broadband connectivity to smaller islands 10 to 12km off shore.
The advantages of white spaces
Comparing white spaces technologies with other radio technologies shows several key advantages. Firstly it's multipoint, with no need for line-of-site connections or to locate end points accurately. That means it's able to operate in high winds and when there are earthquake aftershocks that might cause misalignment of point-to-point systems and might break cables or fibre.
Secondly, you don't need to worry about exact alignment, and can even operate through obstructions and over water. The equipment used in the Philippines was weatherproof, and could be installed anywhere, with a normal antenna. Base stations can be used as repeaters, though the current maximum range is an impressive 12km (with future systems promising up to 40km).
Thirdly, deployment is easy, with dynamic spectrum access management allowing systems to avoid interference. While you might need to climb to place and point the antenna, it's a job that any TV installer can perform. That makes it a lot cheaper to deploy than cellular systems, as you don't need the same level of skill in the personnel who deploy the tech.
Another advantage is that white spaces technology uses unlicensed space in the spectrum, making it easy to work with regulators, and to provide cheaper access as a result. With white spaces aimed at providing rural broadband, that's a significant bonus: you can provide internet access for a very low cost, almost for free. Pending legislation in the Philippines will provide a budget for free network access in lower income areas of the country, allowing it to be delivered to traditionally underserved communities.
People aren't the only possible consumer of this type of service. White spaces is also being considered as a way of giving lower cost connections to the Philippines' national sensor network. Designed to track flooding and seismic activity, it's a distributed network currently using cellular and satellite communications. White spaces would allow more sensors to be added to the grid at a lower cost - and, with experimental sensor packages that can run off coin batteries, it's an option worth considering.