The transformation of a city into a smart city produces both possibilities as well as challenges. EXXETA has looked intensively into this topic. Sustainable development and the interconnection of the infrastructure using innovation and technology can significantly improve a city as well as the standard of life within it. No matter which area – mobility, the environment, energy, healthcare or administration – the Internet of Things allows you to simplify processes and make them more efficient. With intelligent traffic management systems and car park sensors, for example, traffic jams and emissions can be reduced. Needs-based control of water and electricity enable energy consumption to be reduce in agriculture. Sensors on waste containers help to ensure they are emptied when needed, which helps to reduce costs.
Most traditional wireless network technologies are not optimized for the newly emerging IoT application cases because the requirements are high: low energy consumption, long operating times, high ranges and low operating costs. These requirements can be met by the so-called Low Power Wide Area Networks.
A Low Power Wide Area Network (LPWAN) consists of various technologies, which have been especially designed for mobile networks with low bandwidths in the low frequency range. In LPWANs, the end devices do not communicate directly with one another, but via a gateway. Unlike the end devices, this does not have limited resources. The transmission of messages between the end device and the gateway takes place using an LPWAN wireless protocol such as LoRa.
LPWANs are suitable for use in scalable IoT applications:
- The end devices are in a "deep sleep" mode most of the time, which means a low frequency utilisation time can be achieved
- Energy efficiency and long operating periods of several months to many years, combined with relatively low maintenance costs
- No mains power connection needed thanks to the use of batteries
- Location-independent, flexible installation and operation of end devices possible
- LPWANs operate in the public sub-GHz frequency bands, with low frequencies and robust modulation methods
- Significant range of several kilometres and good building penetration
- Telemetry data recorded by sensors are sent to the cloud
- The complexity of end devices can be reduced significantly. A large number of end devices can be integrated
- LPWANs generally implement symmetrical encryption methods
- Secure transport route
A suitable device management system is needed in order to fully exploit the potential of LPWANs. In the current heterogeneous market with different manufacturers, the main challenge relates to the compatibility of the systems. Ubiquitous infrastructures, interfaces and protocols are needed, which can provide a remote device management system (RDM). Via a uniform RDM standard and the continuous further development of this, LPWANs can be efficiently controlled and maintained during their service lives, and stable and secure operation can be ensured via updates.
EXXETA is currently working on an RDM concept in the form of a protocol, which has already been validated and tested and assessed on the basis of a prototypical implementation.
The protocol that has been developed (Low Power Wide Area Device Management - LPWaDM) describes REST-like interfaces, different data packets for the use cases required in RDM and a security concept.
With LPWaDM, a new protocol has been developed, which is based on the OMA LwM2M protocol, but which has been extended and adapted in line with the requirements of LPWANs. It allows RDM to be implemented in resource-restricted LPWANs efficiently and with optimised security. This is realised in part by minimising protocol overhead, enabling multicast updates and implementing multiple commands per packet as well as cascaded encryption.