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Recently, the wireless industry has found that the use of unlicensed spectrum and TV white space are promising areas of research. It’s becoming widely talked about and experts have begun to focus on specific use cases that will drive technology research forward. For example, Microsoft and Google are both spearheading projects to deliver internet connectivity to schools using TVWS in rural areas of South Africa. Use cases for TVWS range from helping bring affordable Internet connectivity to rural areas (like Microsoft’s and Google’s efforts) to how to apply white space for on-demand TV services delivered via broadband. And while the majority of the most popular themes and use cases tend to focus on rural applications, I believe there is major potential with TVWS and unlicensed spectrum in the machine-to-machine market, a market that is growing at an exponential rate. In fact, by 2022, Machina Research predicts 18 billion M2M connections – 2.6 billion of those connections are expected to be based on mobile technology. At that time, 22% of all mobile connections are expected to be M2M compared to the current 2%. That’s a hefty growth spurt.
M2M applications, such as smart meters, are a great example of how white space spectrum can be utilized efficiently. Smart meters typically deliver information in short bursts and involve relatively small file transfers. They are fairly delay insensitive and don’t require a report to be delivered exactly at a given hour, minute or second. Because there are minimal timing requirements required for smart meters, this maps very nicely to the nature of white space spectrum due to the fact that sometimes it is available and sometimes it isn’t because of the very nature of temporary primary user interference. For M2M connections such as smart meters that aren’t time-sensitive, white space spectrum is the ideal partner.
While M2M applications rely on spectrum opening up to share data, rural applications instead rely on areas of low population. However, this scenario is less feasible for the launch of a mass market technology strictly for economic reasons: there aren’t enough users to drive technology in that direction. LTE deployment in rural areas is a perfect example. As organizations and researchers continue to explore opportunities with white space spectrum, M2M will be a main focus and has the potential to be a breeding ground for white space. As we continue to explore options for white space spectrum in the future, collaboration and information sharing will be essential in developing the most meaningful applications.
Another area in which unlicensed spectrum has tremendous opportunity is in M2M communication for several verticals with distinct requirements or standards – for example, connected homes. And while the majority of the connected home applications don’t need to be secure, some industries such as the utility industry will need very secure implementations. Additionally, unlicensed spectrum can use lower frequencies and can be ideal for opportunistic low data rate M2M connections that are not time sensitive, even if the spectrum is shared. This goes back to the smart meters discussion we talked about earlier. The longer range characteristics of unlicensed spectrum channels also facilitate data collection and transfer over longer distances. However, a common M2M platform, which can provide common interfaces and services to the diverse M2M verticals and devices, is beneficial to enable large economies of scale. The M2M standards bodies (ETSI TC M2M, OneM2M) are hard at work defining a common M2M service layer that can be readily embedded within various hardware and software and relied upon to connect the myriad of devices in the field with M2M application servers worldwide.
One more area where TVWS can provide value is with Wi-Fi and other wireless access technologies’ capabilities and functionality. Specifically, one of the challenges the industry faces is the ability to leverage lower frequency bands via the wide-spread use of TVWS for longer range non line of sight access for low data rate M2M applications and potentially for small cell backhaul. TVWS can provide coverage capability for scenarios for these use cases today. For example, leveraging unlicensed spectrum can enable Wi-Fi to expand into more “macrocell” situations, like metro-area deployments. The IEEE 802.11af standards committee has been working on adapting Wi-Fi based technology such as 802.11ac to operate in TVWS spectrum. The standard is expected to be finalized in 2014, and TVWS Wi-Fi devices based on 802.11ac are expected to follow very shortly. The final example I want to share for TVWS potential is that using unlicensed spectrum allows operators to essentially move data traffic to white space to eliminate bandwidth constraints and reduce costs. For example, modifying LTE to operate in TVWS during peak situations or hot spot/small cell TVWS LTE deployments can benefit from cheap and available unlicensed spectrum especially when operating at lower powers and with the benefit of sensing technology. The ETSI RRS and ETSI BRAN standards committees in Europe are defining requirements, architecture and standards to enable both LTE and Wi-Fi technologies to operate in TVWS.
So there you have it. I think it’s apparent that there is lots of excitement around the future use of TVWS and unlicensed spectrum in the industry. The use cases can be endless, but what I really think is the next phase is the use of TVWS and unlicensed spectrum in M2M applications. The opportunities are vast and use of white space will only grow as more opportunities are realized, especially in this market. And it doesn’t just stop with TVWS, as both the industry and regulators are pushing to open up more spectrum in the same vein as TVWS (i.e., sharing the spectrum with a primary user). The Federal Communications Commission is opening up roughly 100 megahertz of spectrum in the 3.5 GHz band to be shared between federal and commercial systems.
