In the summer of 2011, one of the largest commercial trials of white space took place in Cambridge, UK. The trial was conducted by Microsoft and an alliance of ISPs and tech companies, with the network hardware provided by Neul.
Also, NeulNET, launched in the middle of 2011, was announced as the first radio system specifically designed for TV white space that meets all FCC/Ofcom regulations.
These are just a couple of the bigger white space stories to hit the news last year. But, for the uninitiated, what actually is white space and why has it been such a talking point?
White space radios utilise unused channels within the TV spectrum. As the digital switchover approaches in April this year, analogue channels currently occupied are set to become empty and available for use.
The ‘capacity crunch’
As is well known, mobile networks are becoming overcrowded and sufficient bandwidth is an increasing concern. When the current mobile networks first appeared video messaging, smartphones and mobile internet were not yet available, and hence bandwidth was not such a concern. Today, with the massive proliferation of devices occupying our airwaves, the ‘capacity crunch’ within traditional cellular frequency ranges is a real issue.
Depending on the various technologies put in place, it is estimated that as much as 100MHz of spectrum will be available for white space radios to use in the UHF TV band. This is the same amount made available in the auction of 3G spectrum but at a fraction of the cost.
White space also has some very attractive propagation characteristics. Like television signals, white space signals can pass through walls and other obstacles far more easily than higher frequency cellular signals and have a much greater overall range with less use of power.
Of course, as white space sits within the TV spectrum, precautions must be taken to ensure that the technology does not interfere with adjacent TV channels. This is achieved by ensuring that white space radios have an extremely clean transmit mask. Devices also need to look up their location via GPS, and then refer to a central database in order to determine exactly which television frequencies are available for use in their area.
White space network
The process of establishing a white space network is something that Neul – together with other co-ordinating bodies such as the Weightless SIG (www.weightless.org) – is now working towards, and while a current standard for white space exists (IEEE 802.22) there does not appear to be much support for it. A promising M2M standard for white space called Weightless has just been launched and is likely to be finalised during 2012.
Coverage for all
The roll out of a white space network would enable many useful applications in various sectors, including the provision of fixed wireless broadband and the potential to eliminate not-spots and slow-spots, areas where it is currently impossible to get broadband service or an area where the service has a speed below 2Mbps.
Long-term opportunities in M2M are even greater. A projected 50 billion M2M connections will reportedly be required by 2020 and white space works brilliantly for non-time-critical M2M communications. Fifty billion may seem like a large figure to comprehend but it’s not an unrealistic figure when you begin to add together individual applications such as gas meters, electricity meters and healthcare devices. This figure could even be an underestimation.
Licensed or unlicensed?
Although white space will be unlicensed, it will be used very differently to current technologies within unlicensed spectrum such as Wi-Fi and Bluetooth. Fixed wireless broadband and M2M will require a network to be deployed; the former will see a mix of communities and national operators deploy white space solutions. In the case of M2M, such a network would typically be deployed across an entire country.
White space as a mainstream technology will soon be with us. While regulations are still being discussed, in the UK Ofcom is steadily moving towards enabling access and progress remains well on track for this year. In the US, white space has recently been enabled with FCC approval, and the overall direction of the technology is positive. And best of all, NeulNET technology has amply demonstrated its ability to meet the challenging regulations put in place.
White space will see growth of innovation and economic benefits, and could prove to be one of the most important developments in spectrum management for a decade. Bold decisions from all parties should move things forward over the next few months. At this point, regulators and the industry need to support each other in continuing to develop and implement standards to bring the staggering potential of white space to the public.