Narrowband in Narrowband-Internet of Things

In the previous article, we got an overview of NB-IoT – the ‘what’ of NB-IoT (Read:https://www.dhirubhai.net/pulse/nb-iot-sraas/). Now we move on to the ‘why’ of NB-IoT. Why only Narrowband-IoT? Why couldn’t it be wideband IoT or something else?

The Internet of Things covers a wide range of applications across different industries involving a variety of devices that steer diverse computing and connectivity requirements. Thus, connecting the Internet of Things requires heterogeneous connectivity technologies – short-range, medium-range, and long-range – that offer different levels of optimization to address the varying requirements.

Short-range technologies such as Wi-Fi and Bluetooth take care of short-range communication to the network access point while radio technologies cater to medium-range communications. However, short-range wireless technologies become inappropriate for long-distance communication as their communication scopes are limited to tens or hundreds of meters. In the same way, conventional cellular network technologies such as Global System for Mobile Communication (2G/GSM), Universal Mobile Telecommunications System (3G/UMTS), and Long Term Evolution (4G/LTE) are burdened by high power consumption and manufacturing cost to the User Equipments (UEs) because of their complicated designs. So, this gave rise to the need for a cheaper, low-power, relatively less complex, and a standard long-range solution for applications involving wider-area and universal coverage.

Narrowband became the choice. How? Why?

Let’s dive right in.

In general, a signal weakens as the frequency band widens. The weaker the signal, the shorter will be its transmission range. So, a weak signal cannot be transmitted beyond a certain distance. This means that the signal strength has to be high for transmission over longer distances. For high signal strength, the width of the frequency band has to be reduced. Therefore, a narrow bandwidth fits the candidature for a signal to travel farther distances.

In addition, the frequency spectrum of narrowband antennas is divided into as many channels as the frequency allows. Since narrowband systems have a smaller signal bandwidth, the transmitted energy can be concentrated on a smaller portion of the spectrum. This lowers the probability of overlapping with interfering signals and ensures channel-to-channel isolation in narrowband antennae. In turn, non-interference maintains the signal strength (overlapping and interference may decrease signal strength) thereby enhancing the signal’s possibility of reaching long distances.

Many IoT devices are battery-operated, and it is highly desirable of them to last as long as possible on a single charge. Also, the cost of field maintenance associated with devices can be quite intimidating, especially in massive deployments. Not only the planning of scheduled maintenance would be an operational overhead, but also physically locating these mobile devices (for example, asset trackers scattered all over the world) would become a nightmare. Thus, maximizing battery life is very important and the easiest way to do it is power saving.

Power saving can be done in two ways. One can either reduce the amount of data to be sent or the complexity. Narrowband does both. Narrowband channels have low data rate transmissions and low complexity because of small bandwidth, fewer channels, simplified protocol volume, and less computation and performance requirement. For example, a temperature sensor for agricultural purposes doesn’t require sending a lot of data. In fact, every few hours it has to send only a single numeral, the temperature in degrees Celsius or Fahrenheit also making it less complex. Additionally, narrowband, by nature, has low operating power requirements resulting in low power consumption and hence, power saving. Moreover, reduction in the amount of transmission data not only maintains low power consumption but also increases range. ?

Therefore, narrowband fulfills every requirement for long-range IoT communications in terms of extensive range, low power, and low cost. Hence, the narrowband in Narrowband-Internet of Things.

See you next week with the next article in the series. Do comment your opinions and suggestions below.?