What is 4G
4G (fourth-generation communications system) is essentially an improved version of 3G, enhanced with LTE technology. It was first commercially launched in 2007 and was embraced for its higher data rate and congestion capacities. While 4G is undoubtedly more practical than 5G in terms of IoT applications, it is far from ideal, due to high power consumption and high costs of deployment. However, two distinct LPWAN standards that are also based on LTE – NB-IoT and LTE-M – were designed to fulfil the typical needs of IoT and M2M-networks.
History of 4G
In the early 2000s, companies and networking experts started discussing the next possible network technology after 3G. It was ultimately agreed that 3G laid a stable groundwork for the next generation. Thus, the next generation was not meant to revolutionize cellular network technology, but rather be an evolution of the previous 3G network. Therefore, 4G was based on 3G but was improved upon with LTE (Long Term Evolution) technology.
The real development of 4G technology started in 2004 when 3GPP began working on R8 (Release 8), which was the first LTE specification of its kind. The Swedish telecom provider, Telia Company AB became the first in the telecom to provide 4G for commercial usage in 2009. Back then, Telia’s 4G boasted attractive data transmission speeds of up to 100 Mbps per second.
How is 4G better than 3G?
4G is very similar to 3G; however, 4G is way faster. Utilizing its high download and upload speeds, users enjoy broadband-level speeds without relying on a Wi-Fi connection. While the data rates of 4G are much dependent on one’s location, users can take advantage of network speeds up to 21Mbps, which makes it around ten times faster than 3G.
4G is not much different than 3G, as it also transmits (sends and receives) packet data. However, 4G is entirely IP based, meaning that even a regular phone call is essentially a VoIP call. Overall, streamlining the entire network to one standard makes for better user experience as data sent across various systems is more vulnerable to failure or data loss.
Besides improved network speed and solely relying on IP networks, 4G also has a higher capacity than 3G. This means that at peak times, a single tower can provide more users with the best possible connection. Another milestone of 4G is its reduced latency compared to 3G. Users will see a much quicker response to their commands. However, for most IoT use cases, a difference in latency of only several milliseconds will not be significant to most adopters
4G VS 5G for IoT
Theoretically, 5G will be 20 times faster than 4G, with data rates approaching 100MB/s. While this is ideal for data-intensive activities, such as mobile gaming or streaming ultra HD videos, this is most likely irrelevant for most IoT networks, as IoT devices typically transmit very light data packets
4G networks utilize frequency bands below 6GHz. Meanwhile, the frequencies used by 5G networks are much higher, ranging anywhere between 30 and 300 GHz. The higher the frequency, the shorter the signal’s wavelength.
This shorter wavelength has several benefits:
- Antennas can be shorter, and thus mobile phones and IoT devices can be even smaller
- Swift data transfer
- Higher capacity: In a city with many active mobile users, the network won’t become cluttered this easily.
However, there are two downsides to 5G technology that are detrimental to its appeal for usage by IoT- and M2M-enabled devices:
- Signals with shorter wavelengths do not have a far reach. Thus 5G network providers will need many cells to allow for an acceptable level of coverage similar to current 4G coverage. However, these cells are also smaller than 4G towers.
- To allow for high capacity and support a greater number of devices, 5G’s signals are somewhat directional, as opposed to 4G signals. A 4g tower can broadcast its signal in all directions, which greatly improves the range of coverage.
IoT- and M2M- oriented LPWAN Standards based on 4G’s LTE technology
The most common requirements of IoT networks are:
- Being able to send small data packets, even when the IoT device is constantly changing location.
- Low power consumption – IoT tracking devices are typically battery powered and located in remote, hard-to-reach locations. As such, frequently swapping their batteries may not be economically viable.
- Low cost – The most effective IoT-network will rely on a wealth of data achieved by deploying a high number of devices. As such, the cost per device and per network connection needs to be minimal.
- Wide range – IoT-device will be deployed virtually anywhere – in underground tunnels, on container ships, oil platforms or even underwater. Thus, having a high range of coverage will be crucial to many industries wanting to benefit from IoT
When looking at these needs and priorities of most IoT network operators, it becomes clear that while 4G is clearly superior to 5G (high power consumption, high cost & low range), none of them is ideal. There are two standards, based on LTE-technology, that have been designed under consideration of the unique needs of IoT and M2M networks.
NB-IoT is an LTE-based low power, wide-area (LPWA) technology, that has been developed by the 3GPP (Third Generation Partnership Project), which is the same standards organization that also developed W-CDMA for 3G and R8 for 4G.
In contrast to 4G, NB-IoT features improved power consumption, greater range and wall penetration. It also is easy to deploy, as it relies on an already existing spectrum and thus on base station hardware that has already been deployed by the 4G standard.
A GSM module with a battery life for up to ten years can be produced for under five US-Dollars. However, there are some downsides to NB-IoT’s impressive feats. The network latency can be anywhere between 1.5 and 10 seconds, and its maximum speed of 62.5kbps makes it unsuitable for IoT-devices that are meant to provide voice-communication features.
LTE CAT M1/LTE-M
LTE-M is a much more simplistic version, than the regular 4G standard. Just like NB-IoT, it features lower power consumption, cheaper modem costs and higher range compared to 4G. In contrast to NB-IoT, it allows for much higher network speeds (up to 1 Mbps) and much lower latency (50 to 100 ms). Thus, it could also be used for voice and video communication.
LTE-M vs. NB-IoT
While both of these network standards can be defined as Low Power Wide Area Networks (LPWANs) and will likely find their use in IoT and M2M communication, their use-cases will differ.
Data speed of up to 62.5 kbps Data speed of up to 1Mbps
Latency of 1500-10000ms Latency of 50-100ms
Significantly longer battery life than 4g (up to 10 years) Longer battery life than 4G
No mobility support Complete mobility support
Considering the properties of both standards above, some optimal use cases can be identified. LTE-Ms mobility support means that the IoT-device is able to maintain a stable connection, even when changing location. This makes it an ideal standard for IoT-applications related to supply chain management, asset tracking and fleet management. If IoT-devices used are voice- or video-enabled (e.g. CCTV cameras), LTE-M is also the preferred standard thanks to its low latency and high data rate.
NB-IoT, on the other hand, is too slow to allow for voice or video transmission and its lack of mobility support means it should only be used for stationary devices. Since NB-IoT trades off data rate and latency for low power consumption, it is the ideal standard for low-maintenance, stationary IoT-devices in remote or hard-to-reach locations.