In a fantastic, in-depth interview about NB-IoT as an LPWA technology, Prof Riku Jäntti, Head of Department, Department of Communications and Networking, Aalto University, talks to us about developing an NB-IoT proof of concept in Finland, and the implications of this on the LPWA ecosystem.
Prof Jäntti presented this as an application case study at LPWA Barcelona.
1. Tell us about developing an early NB-IoT proof of concept in Finland
We have been working with software defined radio implementations of radio access networks since 2011. We initially implemented the physical layer and selected MAC and RRC functions of the TD-LTE release 8 base station and user equipment. Our base station and user equipment software has been written in C++ and run in a regular Linux PC. The key component of our implementation is a hardware abstraction layer that handles the synchronization issues and conversion between symbol time (hard real time) and sub-frame time (soft real time). Our software architecture greatly simplifies the base band processing implementation and allows us to rapidly develop new features. It was used as a demonstration platform in a EU H2020 project METIS. In that project, we demonstrated how network controlled device-to-device communication with interference cancellation can be implemented within the LTE frame structure. This demo was presented in Mobile World Congress in 2015.
The NB-IoT proof of concept was developed in Finnish Funding Agency for Innovation (TEKES) funded project called Take-5 and an EIT Digital funded project ACTIVE. We worked in close collaboration with Ericsson Finland who help us to follow the standardization work as it progressed. We implemented the stand alone version of the NB-IoT that can run on a GSM carrier. The Finnish operator DNA allowed use to use one of their GSM 900 carriers for testing.
2. What are the implications of this research and proof of concept on the LPWA ecosystem?
We believe that our research can help in improving the NB-IoT system through rapid prototyping and testing. Our platform enables cloud based NB-IoT deployments that could potentially enable completely new kinds of use cases and applications.
3. What else will you look to develop as part of the Aalto University research team?
We use the current implementation for studying the physical layer performance of the NB-IoT system. We are currently developing the missing MAC and RRC functions and S1-interface to allow system wide studies.
Our platform allows testing of different NB-IoT use cases and trying out even non-conventional use cases and features that are not yet supported by the standard. Some potential examples would be cloud based provisioning of NB-IoT (as a service), femto cell like deployments for large buildings, and satellite based NB-IoT deployments recently suggested by ESA.
4. As a researcher, what excites you about LPWA?
LPWA sets new requirements and opens up new use cases. These in turn open up new research problems that have high practical value.
5. What are you most looking forward to from LPWA Europe?
We are looking for new contacts and demonstration opportunities. As researchers we are especially keen on finding new and unexpected use cases. The NB-IoT technology is mature enough to cover wide variety of needs. LPWA forum is a good opportunity to understand the momentum behind different activities and directions.