How Low Power is NB-IoT?

nb-iot

NB-IoT is considered a licensed low power wide area networks (LPWANs) technology supported by your local telecom operator. That means each device requires a SIM card and monthly or annual payments to your operator just like your cell phone. The benefit is that you don’t need to manage the infrastructure; you do not need to install your own base stations.

The key advantage of NB-IoT is the protocol is synchronous and designed to optimize the spectral usage and throughput of the network. This optimization for spectral utilization comes at the cost of compromised battery life and recurring costs (monthly or yearly).

Unlicensed LPWANs, such as LoRaWAN® and Weightless™ are optimal for longer battery lifetime. If sensor data is small and infrequent (one or twice a day), LoRaWAN could be the optimal choice being an asynchronous protocol. If data is larger and data transmissions must be acknowledged then Weightless stands alone as the option for a synchronous protocol for private networks.

The effect of asynchronous versus synchronous protocols has significant impact on the battery lifetime of sensors.

Semtech conducted a comparison using the T-Mobile NB-IoT network available in the U.S. The NB-IoT sensor consistently took more than 20 seconds of active time to negotiate a slot to communicate an 11-byte packet. The average current consumption over this 20 second period was 40mA. In comparison, sending the same 11-byte packet over LoRaWAN required an active time of only 1.6 seconds, with an average active current consumption of 6.4mA. This translates into greater than 50 times advantage in battery lifetime for LoRaWAN.

Take an example application: wireless, battery powered, pushbutton. A LoRaWAN-enabled pushbutton and an NB-IoT pushbutton each were equipped with a 600 maH battery. The LoRaWAN device could support roughly 70,000 button presses on a single battery,  while the NB-IoT button could handle only about 2,000 button presses on a single battery. The difference is quite drastic.

When choosing a LPWAN technology, be sure to thoroughly review the application requirements. One size does not fit all.

 

 

LoRaWAN vs. Sigfox vs. Weightless-P: Simulation Results in the “Real World”

In wireless communication, the Hata Model for urban areas, also known as the Okumura–Hata model for being a developed version of the Okumura model, is the most widely used radio frequency propagation model for predicting the behaviour of cellular transmissions in built up areas. This model incorporates the graphical information from Okumura model and develops it further to realize the effects of diffraction, reflection and scattering caused by city structures. This model also has two more varieties for transmission in suburban areas and open areas. (source: Wikipedia)

The Hata Model simulation was conducted for Sigfox, LORA, and Weightless-P with the base station height set at 30m and the end devices heights set at 0.5m. The following simulation was conducted at Ubiik (hardware developers for Weightless-P) but we have checked their math and our team has confirmed the numbers are accurate and unbiased.

Let’s first take a look at the U.S Results (902-928MHz)US compaire.png

 

US2 9.54.52 AM.pngUS3.pngUS 1.png

Now let’s take a look at the results in Europe (863-870MHz). The only difference is LORA is only able to use a smaller bandwidth.

EUR compaire.pngEUR1.pngEUR 2.pngEUR 3.png

 

Let’s see what these numbers mean for an actual Smart Metering deployment (click here)

(If you would like to contribute/make edits/suggestions please contact us at techgu.rooh@gmail.com)

sources: (http://www.ubiik.com/lpwan-comparisons)