Breaking the Frequency Barrier: Using Millimetre Waves for Mobile Services

Breaking the Frequency Barrier

It is estimated that by 2020 there will be 50 to 100 billion wireless devices in use. That means the radio frequency spectrum – the airwaves that transmit signals for everything from our mobile phones, to TV shows and emergency communications for firefighters and ambulances – will become increasingly crowded. That could result in slower wireless service, disruptions, dropped calls, and in extreme cases, no service at all.

Therefore, we need to find more wireless capacity by making better use of the existing spectrum. The Communications Research Centre (CRC), Canada's primary advanced telecommunications research facility, is exploring the potential of a portion of the spectrum that is not used for broadband mobile services, and that is home to extremely high frequency waves known as millimetre waves (MMW). Currently, these higher frequency bands of the spectrum are used relatively lightly, for services such as satellite, line-of-sight microwave communications and radar transmissions, while the lower frequency bands are crammed, carrying service for the vast array of other wireless devices such as our smartphones and tablets, garage door openers, etc.

Millimetre waves are about one to ten millimetres long and can travel much shorter distances than those in the bands used by our smartphones today, which measure tens of centimetres in length. The shorter MMW are also easily blocked by things like the rain, trees and buildings. They can be absorbed by the gases in the atmosphere and they need more power to send and receive data. For these reasons, this high frequency spectrum was previously considered to be unsuitable for mobile communications.

But CRC research scientist Dr. Philip Vigneron says some of the negative aspects of MMW are also positives.

"CRC research is looking at how to take advantage of the disadvantages," he says. "For example, because MMW have a shorter transmission distance, they lend themselves to greater frequency reuse, or sharing the same bandwidth with different users."

This could be accomplished by strategically placing numerous portable miniature base stations throughout cities. These would relay signals to users at any location using much smaller antennas than those traditionally needed for lower frequency signals.

Dr. Vigneron says higher frequency MMW could be put to more efficient use and shared among the growing number of users.

"We are currently limited by bandwidth. We want to move into a world where we're not limited, so the CRC is investigating the conditions required for opening up the higher frequencies for mobile broadband use, and how we may share this bandwidth."

This will be particularly important with the advent of 5G – the fifth generation of wireless technology – where it may be possible to re-use the same bandwidth, for example, on different floors of a high-rise building.

"5G is the beginning of a new cycle," he says. "CRC research into how millimetre waves can be used will ensure that new equipment deployed by industry and service providers makes the best possible use of the spectrum."

5G also has the potential to make cities smarter, allowing people, devices and services to all communicate with each other for greater efficiency, savings and safety.

"Think of every possible service and assume it can communicate anywhere, any time in a smart city," says Dr. Vigneron. "Every parking meter can talk to the city. Every streetlight; so that if a bulb burns out, it calls home to say 'hey, I need a new bulb.' With smart cities, maybe snowplows could be driverless overnight. CRC is demonstrating how to achieve the best wireless coverage at the lowest possible cost."

Contact us to learn more about our research in millimetre waves, and other Grand Challenges research projects and collaboration opportunities.