Hidden at the end of a recent Times UK article about street parking restrictions, was a note about new smart parking sensors at London's Stansted Airport.

By detecting the presence of a car parked above, sensor networks can give cities real-time data about parking trends, drivers can be guided to where spaces are available, and enforcement can be more discreet and more targeted. Like smart street lighting, it’s a great example of a smart city internet of things (IoT) deployment that combines clear benefits for citizens with a business case for city authorities.

Technology advances in parking are inevitably reported as a new way to penalise drivers, but by removing the uncertainty about availability and prices, and by helping drivers to avoid unexpected penalties, a lot of today’s parking angst could be swept away.

And that’s before you start to look at the new possibilities that sensor networks could provide, such as variable pricing depending on time of day, different rules for resident or disabled parking using vehicle type sensing, and the ability to adapt parking rules quickly to meet changing community needs.

But these are early days for smart parking, and robust technologies have only recently emerged that meet its demanding requirements:

  • Sensor type - early systems use infared, like a TV remote, but these can quickly get dirty. The latest systems use robust magnetic sensors.
  • Wireless network – burying a radio in the ground and then parking a large lump of steel above it is quite a good way to block radio signals. And parking is often inside heavy steel and concrete structures or underground. So you need a radio network that it specifically designed for long range low power operation with a simple deployment that avoids the need for lots of unsightly gateway and relay boxes.
  • Battery life – for the business case to work, the battery needs to last between 5 and 10 years.
  • Cost – A smaller battery reduces both unit cost and installation cost, and the wireless module and sensor need to combine long life with very low unit cost. And the radio network needs to combine tiny per-bit and per device costs with low cost deployment. Traditional cellular and short range mesh approaches don't get close.

Telensa (shameless plug alert) is pioneering the new wave of smart parking technology in the UK, and now has large-scale deployments in major cities in Russia and China. This is based on the same Ultra Narrow Band (UNB) wireless system that controls smart city street lighting networks around the world.