TV White Space Super Wi-Fi

Demand for wireless communication is ever-increasing. However, the frequency spectrum is a scarce resource that cannot be created. This has resulted in an issue commonly known as "spectrum crunch" -- a phenomenon where demand for spectrum outpaced supply that resulted in congestion and drop in wireless communication quality.

Ironically, measurements done at many places globally concluded that spectrum utilisation was only around 5-15%. This calls for a need to use next-generation technologies to utilise spectrum in an innovative manner in order to ensure sustainability. TV White Space (TVWS) is the first technology that uses spectrum dynamically. It is able to find pockets of unused spectrum dynamically and utilise them for communication. Thus, significantly improve spectrum utilisation. TVWS is also known as Super Wi-Fi as it covers much larger range than Wi-Fi.

TVWS can also be touted as the next "sharing economy" in the spectrum. Its concept is similar to Uber or Airbnb where resources (in this case spectrum) are shared whenever or wherever they are not utilised.

With lower frequencies in the UHF range of 470-698 MHz, TVWS is able to travel much longer distance and penetrate through obstacles much better than alternatives. As a comparison, TVWS can easily cover areas 10 to 100x that of Wi-Fi, thus, making it suitable for applications where coverage and penetrations are key.

TVWS dynamically chooses vacant channels from a list of unused TV bands in the UHF spectrum for 2-way wireless communications. Whenever it detects interference or the presence of incumbents, the system will intelligently switch to another suitable channel to continue the communications.

Based on long-range characteristics, the solutions are designed as backhaul for communications. This is especially useful to cover suburb or rural areas that are up to 10km away or when cabling proved to be difficult or too costly. To ease installation and reduce deployment cost, our solution has a built-in antenna with only a single port for Power-over-Ethernet (PoE). Installers just need to plug in a Cat5/6 Ethernet cable, the whole installation is done.

Similarly, the good penetration characteristics are also exploited for connecting Internet-of-Things (IoT) devices. For low volume IoT, alternatives such as cellular, Wi-Fi, Bluetooth, SigFox, LoRa or ZigBee might be sufficient. However, when IoT scales up, all these solutions start to fail due to either inability to penetrate through obstacles or lack of spectrum for communications. For example, there is a total of 5 MHz bandwidth from 920-925 MHz band that are being shared by SigFox, LoRa, ZigBee, the future IEEE802.11ah and many proprietary systems. It is not difficult to see that this is not sustainable for the long run when IoT scales up. In contrast, TVWS has 180 MHz allocated by IMDA. Coupled with good penetration characteristics, TVWS can play a key role in large-scale IoT.

The potential applications of TVWS can be broadly classified into 2 categories:

1. For broadband connectivity

• Rural Internet
• Cable replacement (e.g., as backhaul for Wi-Fi hotspot)
• Backup / redundant networks
• Fast deployment (e.g., during disaster, ad-hoc events)

2. For IoT connectivity

• Smart grid
• Precision agriculture
• Industrie  4.0
• Facility management
• Surveillance

Worldwide, the digital divide is an issue. Less than half of the global population is digitally connected. The other three billion populations (O3B) has no connectivity due to poor infrastructure, poverty or unaffordability. On the other hand, developed countries are moving towards smart cities to solve urbanisation issues. IoT is a key enabler for smart cities and it is expected to have 50 billion IoT devices by 2020. The requirement on wireless connectivity is ever increasing that results in spectrum crunch.

Connecting the rural areas have been the mission of UN and many countries. UN wants to connect up 10's of millions more people from the developing countries. There is a bottleneck now as connecting the next village has become more and more expensive due to lack of new technologies to address the issues. Fortunately, with TVWS, villages can be easily connected with a fraction of the total cost required using current technologies.

For IoT, it is still at its nascent stage where the real issues with massive IoT are not obvious yet. By the time IoT scales up, many issues such as insufficient spectrum, congestion, blockages will start to surface. This is where TVWS comes in handy to solve these issues.

The key advantages of long range and good penetration for TVWS translate into the following advantages:

• Lower cost of capital expenditure (CAPEX): with longer range and better penetration, a smaller number of devices are required to connect up an area. As such CAPEX can be significantly reduced. Savings of up to 90% can be expected.
• Lower cost of operating expenditure (OPEX): with license-exempt nature of TVWS as well as lesser installations (site access, rental, etc.), the cost of owning and operating a network is much lower than alternatives.
• Easier and faster deployment: TVWS can be deployed very easily and quickly. This also translates to lower cost of deployment besides the non-tangible savings it gives such as minimal disruption to people & businesses, faster replacement of existing technologies, etc.
• Better performance: TVWS is lesser affected by rain, haze and other natural disturbances. Therefore, TVWS network is much more stable compared to networks using higher frequencies such as 2.4 GHz or 5.8 GHz.
• Lower latencies: due to the larger available bandwidth, the latencies, especially for large networks are greatly reduced. Comparing to narrow-band IoT networks operating at 900 MHz bands, the latencies can be reduced by up to 100 times.
• Reduced security risk: networks with narrower bandwidth and thus smaller capacity are more susceptible to security attacks, e.g., when DDoS attacks happened, smaller capacity networks can be brought down easily. With larger capacity available for TVWS, DDoS attack is more difficult.