Unveiling the secrets of NB-IoT battery life

In the realm of NB-IoT, a key objective outlined in the 3GPP standard is to ensure that device batteries last a minimum of 10 years. This ambitious goal is achieved through the incorporation of mechanisms such as eDRX (extended discontinuous reception), TAU (tracking area update), and PSM (power saving mode), all of which contribute to reducing power consumption.

NB-IoT’s ambitious battery lifespan goal

NB-IoT is considered the technique for the mobile networks that can place your device in the 10-year battery club. The battery life of NB-IoT, as with any Low Power Wide Area Network (LPWAN) standard, is influenced by various factors. Focusing solely on the radio part allows for certain calculations and assumptions.

Numerous reports delve into real-world battery performance, and “Power Consumption Analysis of NB-IoT and eMTC in Challenging Smart City Environments” by Pascal J├Ârke, Robert Falkenberg, and Christian Wietfeld serves as an excellent reference. According to their findings, with a coupling loss of 144 dB (signal loss occurring in the air during transmission between two points), the estimated battery life is an impressive 25 years for a payload of 84 bytes transmitted once a day. With a coupling loss of 154 dB, we approach 18 years, while a coupling loss of 164 dB results in a battery life of four years. It is crucial to approach claims of 10 or 15 years of battery life with skepticism unless a range is specified or conditions are explained, as battery longevity can vary significantly.

Device dynamics: beyond the radio interface

Beyond the radio interface, the actual battery life is also contingent upon the specific device in use. Questions arise: How much power do the components on the circuit board consume in idle mode? How efficient is the software in conserving power? Can the device filter out unnecessary data before transmission, ensuring that only the most crucial information is sent? These considerations highlight the multifaceted nature of battery life in NB-IoT devices, emphasizing the importance of a holistic approach to power optimization.

In conclusion, achieving an extended battery life in NB-IoT devices is a nuanced process involving a combination of standardized mechanisms and careful consideration of hardware and software efficiency. As the IoT landscape continues to evolve, understanding and implementing strategies for optimal power consumption will be instrumental in realizing the full potential of this transformative technology.