Live test: NB-IoT proves indoor effectiveness

Until now, intelligent meters have sent small amounts of data at predetermined intervals – usually every couple of minutes – to a so-called gateway, which, in turn, relays it onward to a server. The meters communicate directly with the cloud via NB-IoT. The whole system is less complex, more affordable and provides greater opportunities to deploy wireless modules than previous solutions. NB-IoT is also very energy efficient. A module can operate for years with a single battery charge – a huge advantage for anyone lacking an electrical outlet near their power, gas or water meter in the basement.

And the amazing building penetration is just one of the many advantages NB-IoT has over traditional wireless (GSM or LTE). The specific characteristics of the technology (see box) enable data transmission even through thick walls. So it’s the best option for reading heating meters deep inside a cellar via the Internet, just to name one example.

Working together with the property service provider ista International, Deutsche Telekom carried out a comprehensive measurement test of its NB-IoT network. ista is one of the world’s leading firms focused on improving building energy efficiency – especially the collection, billing and visualization of consumer data for apartment buildings and commercial property. For the test, ista allowed access to more than 500 measurement points in approximately 60 apartments in Germany’s Cologne/Bonn region.

The independent measuring firm P3 Communications carried out the testing, for which several devices were deployed: NB-IoT modules placed on different floors of a building sent measurement data from the meter to an outdoor receiver, while a scanner monitored the signal strength of the transmission. The results were convincing: The NB-IoT modules on the ground floor and upper floors were able to connect to the network in 100 percent of all attempts. The modules in the cellar – where consumer meters are often located – achieved a 95-percent connection rate. Once connected, data transmission was successful nearly every time (99.75 percent).

No other wireless technology can provide a similar level of reliability, especially not for underground connections. NarrowBand IoT could therefore soon become the most widely used standard for many building applications – including smart metering, smart homes and property automation.

The results of the test can be found here.