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Athens, 28/09/2018

Since the first pilot projects around the world proving the connectivity and performance merits of NB-IoT networks, our view over the emerging sensor design trends has dramatically changed.

At the beginning, let us understand what is going to change with the introduction of NBIoT networks.

-These networks have been designed to broadcast on existing ubiquitous frequencies that we use since the 90’s. Mobile network companies have been continuously investing in the infrastructure upgrade since then. Nowadays, these networks, have been upgraded to receive very small (constraint) messages over a new protocol that is called NarrowBand. Sensors nowadays attach to the wireless infrastructure your mobile phone is using. Nothing more, nothing less. The networks are there and they have been designed to facilitate more that 50.000 sensors per cell per base station. Network operators should thing big, our innovation team has a shifted mindset towards massively deployed sensors. 

-The protocol opts for constraint devices powered by batteries. What we practiced so far, is that any type of sensor used, should be either connected to the power grid (under a AC to DC transformer) or being powered by batteries (e.g the vehicle battery). This requires the end mile integrator to include in his budget the installation cost. That includes extra copper deployed, extra labor and higher maintenance OPEX. NBIoT networks simple render this practice obsolete, because:

  1. All the sensors are battery operated; therefore there is no need for powering them up, either from the grid or any type of bulky battery configuration. This accounts for immediate reduction of CAPEX cost.
  2. All sensors can operate in very low signal thresholds. With the current NBIoT version released, we have attached to a base station 2,5 Km away, with a signal level of -131 dBm. For the RF guys around there, this is simply a magnificent breakthrough!  Never before a city network can operate in such low sensitivity levels and next releases claim that network connection can be even possible at lower signal levels.  How does this translates to cost reduction? First of all, no external antennae have to be used. Just a F-inverted meander monopole printed on the sensor as a radiating element and you can successfully transmit and receive. Second of all, since NBIoT protocol can establish connection between the sensor and the base station even in underground installation schemes, therefore zeroing any need of deploying extra power or data networks.
  3. Constraint devices (like NBioT sensors) need to bear ingenuity with respect to data payload and power preservation. This is where innovation kicks in. Ingenuity of a sensor is the way we make the sensor operate under a minimum data transferring payload, without sacrificing data value. Why we need such a performance rationale; simply because our mindset must take account that we are considering tenths of thousand of sensors per base station. Now, consider the deployment of wireless networks in a city level. There are thousands of base stations deployed. Now, multiply the capacity per base station with the number of possible sensors per base station. The number becomes massive with a lot of digits. Now consider operating millions of sensors deployed in an area to measure any type of physical value or human activity. If the sensors are dummy, then a database will be gathering data junk along with valued data, therefore high costs of preserving and mitigating towards meta-data. Now imagine a sensor capable of preserving the lowest OPEX in IT infrastructure possible, by sending only data when the physical value measured changes. This is possible on the firmware level, where algorithms or machine learning code can govern the way sensors react to their measurement. Adding the need for battery constrained devices to operate for a decade, the firmware code must be advanced enough for the sensor to ‘wake up”, “sample” and “sleep”, under an orchestrated scenario.

In Fuelics, we do not just create sensors, but we create tailor-made sensors for the end user application. This is not an easy thing to do and requires experimental data and practical knowledge in order to reverse engineer the field installation specifics into firmware code. The results are magnificent by the way. We have sensors piloted in the open field that create 1/20th to 1/50th or less of the custom data payload of non-constraint sensors (e.g Power grid GPRS operating sensors). This straightforwardly minimizes OPEX and the northbound application framework can produce services by using only thin data payloads.

-Constraint devices for massive deployments must be cheap. Everybody asks for cheap sensors, but actually nobody knows why! We believe that for the first time, since we are opting for battery operated sensors that will be operating for at least 10 years, we need to change the narrative. Sensors cannot be considered as passive devices. Even if installation costs are minimum, a cheap sensor is a sensor that simultaneously is CAPEX and OPEX cheap. But, since we are discussing about a decade of operating life, what is more important to a business model is the lowest possible OPEX cost.

Summing up, in order to set things in new perspective, we need to be able to design and develop sensors that will be able to facilitate new types of business models that take under consideration the revolutionary aspects of the NBIoT protocol, the new type of specifications for constraint devices, the new rationale on minimizing data throughput and lastly but not least, the nearly zero $ yearly data tariff.

NBIoT networks change the narrative in legacy IoT integrated systems, by transforming the operational and manufacturing guidelines to support the transition from dummy to clever sensors, from CAPEX intensive projects to long term thin OPEX spending, from sensor agnostic IT applications to sensor specific applications.

Dr. Evangelos S. Angelopoulos is an industrial adjunct research in NCSR Demokritos developing exponential fuel and smart city sensors.

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New hardware design trends for constrained NBIoT battery operated sensors