Narrowband IoT in the cloud
An early proof of concept implementation of narrowband IoT (NB-IoT) has been demonstrated by researchers from Aalto University and Ericsson Research in Finland. Check out details and catch a video about the prototype!
Our group in Ericsson Research has worked together with a team of researchers from Aalto University in Finland on NB-IoT. We were there when they demonstrated over the air transmission two weeks back over a GSM carrier. Earlier in July the team already tested operation over ISM bands, as mentioned in this press release by EIT DIGITAL which enabled the collaboration project.
The implementation follows a Cloud RAN (C-RAN) architecture where protocol handling and radio access network (RAN) functionality is moved to a cloud computing infrastructure. In this demonstration all the NB-IoT protocol functions, including physical layer processing, are performed on standard Linux PCs and the Radio Frequency (RF) processing is performed in software defined radio units (Universal Software Radio Phepral, USRP).
To allow flexible deployment the NB-IoT standard has three deployment options, standalone operation, guard band operation and in-band operation.
Figure 1 Operation modes of NB-IoT
In the demonstration, NB-IoT in standalone mode was run in a GSM carrier borrowed from the Finnish mobile operator DNA. This is possible since the bandwidth of the NB-IoT signal is only 180 kHz, less than the 200 kHz GSM carriers. Re-farming GSM spectrum in this way can be an attractive way for operators to support IoT devices. Figure 1 shows a screen shot of the spectrum analyzer used to confirm that the narrow band signal is being transmitted over the right GSM carrier.
Figure 2 The narrowband IoT signal using a GSM carrier on 929 MHz.
To show the flexibility of the SW defined radio implementation, the team also showed how NB-IoT can run on a test frequency in the 630 MHz band as well as in the 2.4 GHz ISM band used by, e.g., Wi-Fi. Check this video of the prototype test:
The transmitted data was generated with a simple IoT sensor application gathering temperature, air-pressure and humidity data. The information was then periodically transmitted together with the sensor’s GPS position over an NB-IoT radio link and collected in the cloud.
Figure 3 The NB-IoT base station used in the demonstration on the roof of the Aalto University building
In the future, the potential of the C-RAN architecture will be explored and the performance of NB-IoT will be evaluated through measurements.
The new NB-IoT (Narrowband Internet of Things) standard is being completed by 3GPP as described in our recent blog post Narrowband IoT standardization soon finalized. The technology is designed to provide low device complexity, very low battery consumption and substantially increased coverage compared to earlier 3GPP technologies, with commercial releases expected later this year. The demonstrated implementation follows the main agreements in 3GPP.
Figure 4 Us together with the group of researchers at Aalto University
Ericsson Research, Finland.