Internet of Things (IoT) is no longer the overhyped buzzword it once was. It has revolutionized technology and industry. The evolution of IoT is so rapid that we now have over a billion IoT devices in use. However, to truly make IoT devices ubiquitous, we have to look at other forms of connectivity. Cellular IoT is the future.
Today, over three billion people use a smartphone. We can access Maps, live weather information, news, send and receive emails and do much more. How? Our smartphones can connect to the internet. We can connect either using Wi-Fi or through a Cellular telephone service provider. For operating mobile phone networks, Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA) are the most commonly deployed. A cellular network does not need a router, unlike the router through which you access Wi-Fi at your home or your favorite cafe. A cellular network also has a much longer range than a standard Wi-Fi network.
The advantages of Cellular networks over Wi-Fi networks, as stated above, are needed to understand how it will shape the future of IoT.
Internet of Things (IoT) is no longer the overhyped buzzword it once was. It has revolutionized technology and industry. The evolution of IoT is so rapid that we now have over a billion IoT devices in use. However, to truly make IoT devices ubiquitous, we have to look at other forms of connectivity. Cellular IoT is the future.
Contents
- What is Cellular IoT?
- Current problems of Cellular IoT
- Two major types of Cellular IoT
- Which is better – NB-IoT or LTE-M
- 5G – The way forward for Cellular IoT?
- Conclusion
What is Cellular IoT?
Cellular IoT is used to define IoT devices that are connected to the internet through cellular networks, similar to the ones used by your smartphone. Instead of using Wi-Fi, Bluetooth, or other forms of connectivity, IoT devices can connect to the internet through cellular networks. Why is this hailed as the future of IoT? The existing cellular network infrastructure can be effectively utilized to connect billions of IoT devices.
For a long time, cellular IoT devices consumed a lot of power. Many of us would have experienced this issue in our smartphones. Switching on the cellular network would invariably drain the battery before long.
Cellular networks typically focus on increased range and bandwidth while compromising on battery power. This is not much of a problem for our smartphones or tablets, as they can be recharged often. However, when it comes to IoT devices, we expect battery life to range from a few months to a few years.
Current problems of Cellular IoT:
4G and LTE networks consume too much power to be considered as a viable option for IoT devices. IoT devices currently use Low-Power Wide-Area Networks (LPWAN) such as SigFox, LoRa (Long Range), and Weightless. These networks are characterized by their long-range, low power consumption, and low cost. These LPWAN’s operate in the unlicensed spectrum compared to the licensed spectrum and standardized infrastructure of cellular networks. The licensed spectrum is expensive to acquire and deploy. LWPAN’s have options that are free for all users and offer greater customizations to the end-users.
But the above problems of cellular networks for IoT applications are being overcome and we have dedicated cellular technologies just for IoT devices.
Currently, most of the IoT devices run on two cellular technologies - LTE-M and NB-IoT.
Two major types of Cellular IoT:
Before delving into the two types, we need to understand that notwithstanding the specific distinctions and different applications of the two types of cellular IoT, we can choose the type depending on whether your country uses LTE or GSM. Currently, only the United States of America, Australia, and a few European countries have national LTE-M networks. Most of the other countries rely on GSM.
LTE-M/ Cat-M1 (LTE Cat-M1)
LTE-M (Long-Term Evolution for Machines) or Cat-M1 is often viewed as the second generation of LTE for IoT applications after Cat 0 and Cat 1. LTE-M is a type of low-power wide-area network that was developed by the 3rd Generation Partnership Project (3GPP).
LTE-M offers a higher data rate, smoother handover (better mobility), and voice over the network. However, it is expensive and is not useful in small-scale applications that require low data rates. Heavy data applications such as self-driving cars and emergency services which need real-time data transfer, prefer LTE-M.
The following table shows the maximum channel bandwidths and other parameters of LTE-M in releases 13 and 14 of 3GPP:
| LTE Cat-M1 | LTE Cat-M2 | |
| 3GPP Release | Release 13 | Release 14 |
| Downlink Peak Rate | 1 Mbit/s | ~4 Mbit/s |
| Uplink Peak Rate | 1 Mbit/s | ~7 Mbit/s |
| Latency | 10–15 ms | |
| Number of Antennas | 1 | 1 |
| Duplex Mode | Full or Half Duplex | Full or Half Duplex |
| Device Receive Bandwidth | 1.4 MHz | 5 MHz |
| Receiver Chains | 1 (SISO) | 1 (SISO) |
| Device Transmit Power | 20 / 23 dBm | 20 / 23 dBm |
LTE-M offers lower latency and higher throughput as compared to NB-IoT.
NB-IoT
NB-IoT ( Narrow Band IoT) was developed by 3GPP, optimized for lower bandwidth thereby “offering unmatched spectrum flexibility and system capacity, in combination with qualities such as energy-efficient operation and ultra-low device complexity.”
It has lower data rates than LTE-M. This means that it consumes less power and can be used efficiently for stationary sensors. It also boasts of slightly higher refresh rates than LPWAN’s like LoRa meaning that it is highly effective for systems like soil sensing, and smart metering systems like those in parking lots and oil tanks. Since it uses only a narrow band of the cell tower, it can be particularly effective in countries that rely on GSM.
The following table lists the 3GPP cellular standards for LTE Cat NB1 and LTE Cat NB2 of NB-IoT
| LTE Cat NB1 | LTE Cat NB2 | |
| 3GPP Release | Release 13 | Release 14 |
| Downlink Peak Rate | 26 kbit/s | 127 kbit/s |
| Uplink Peak Rate | 66 kbit/s (multi-tone)16.9 kbit/s (single-tone) | 159 kbit/s |
| Latency | 1.6–10 s | |
| Number of Antennas | 1 | 1 |
| Duplex Mode | Half Duplex | Half Duplex |
| Device Receive Bandwidth | 180 kHz | 180 kHz |
| Receiver Chains | 1 (SISO) | 1 (SISO) |
| Device Transmit Power | 20 / 23 dBm | 14 / 20 / 23 dBm |
Which is better – NB-IoT or LTE-M?
As we can see from the coverage map above, LTE-M is mostly present in North America, parts of South America, Europe, and Australia. NB-IoT is present more in Europe and Asia.
From the specifications of both, we can conclude that NB-IoT is better suited for low data rate connections, stationary use, and low-cost devices. On the other hand, LTE-M is optimized for higher data rates, mobility (asset tracking, vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communication, etc.) and voice over LTE or VoLTE technology.
Each protocol has its own use cases and it is entirely up to the provider to decide which protocol to use.
5G – The way forward for Cellular IoT?
It is highly possible that with the advent of 5G, we could see newer and more advanced chips that can efficiently use 5G in cellular IoT devices.
The latest hype over 5G is not baseless. It is supposed to be smarter, faster, and more efficient than 4G. With speeds of 100 gigabits per second, it is about 100 times faster than 4G.
Both NB-IoT and LTE-M are rapidly growing. The Ericsson Mobility Report for 2019 states that NB-IoT and LTE-M technologies shall account for more than 50 percent of cellular IoT connections in 2025. The report also forecasts that 5G could cover 65% of the world’s population by 2025. Read the full Ericsson Mobility Report for 2020 here.
It is highly possible that with the advent of 5G, we could see newer and more advanced chips that can efficiently use 5G in cellular IoT devices. The extremely high data rates could open the floodgates for applications such as self-driving cars and Augmented/Virtual Reality.
Conclusion
The power of Cellular IoT could soon be unleashed, with more countries adopting national LTE-M or NB-IoT networks. 5G shall soon replace 4G and cellular IoT devices would be able to use 5G for high data, real-time applications. Billions of cellular IoT devices could flood the market, connecting every aspect of our lives. Cellular IoT is capable of transforming illusion into reality.
