The full name of LTE Cat is LTE UE-Category, LTE refers to 4G LTE network, UE refers to the user equipment, and Category is the level.
Cat 0 is an LTE terminal grade written into the 3GPP Rel.12 standard, which supports a lower rate and lower power consumption version. Cat 0 and Cat 1 both point to the broad IoT market, enabling lower power consumption and lower-cost IoT devices to connect to the LTE network. Supports lower category, which is critical for IoT applications such as wearable devices, smart homes, and smart meters.
Since the levels are different, their capabilities are definitely different. Simply put, LTE Cat affects the upper limit of the 4G LTE uplink and downlink network speeds. Generally speaking, the maximum upload and download speed that the user equipment can achieve.
There are not only 4 and 6 levels in LTE Cat. According to the 3GPP Release definition, UE-Category is divided into 10 levels from 1 to 10, among which Cat 1-5 is in the R8 group, and Cat 6-8 is in the R10 group. , Cat 9-10 is in the R11 group, Cat 11-15 and Cat 0 are classified as the Release12 group, and Cat.M1 (eMTC) and Cat NB-1 (NB-IoT) are classified as the Release13 group.
The entire definition is continuous. At present, the LTE network used by our mobile phones mainly refers to LTE Cat 4. In 2009, LTE Cat 1-5 was specifically divided by 3GPP and is oriented to the future IoT application market.
LTE Cat4/Cat6 is also the network transmission technology level of 4G mobile phones, and the faster CAT10 has been commercialized.
When LTE was originally designed to solve one of the most important requirements, it must be fast enough.
Although this technology can meet the needs of mobile broadband communications, it cannot be used well in some applications, such as wearable devices, industrial sensors, and household appliances.
This type of equipment is characterized by its small size, and battery power, and is often placed in places with poor network coverage or even no signal, such as basements.
3GPP has added several enhanced standards to LTE technology, some of which are simplified, and some are completely new, and used to connect IoT devices.
NB-IoT and LTE Cat M1 and LTE Cat 1, how to choose the correct LTE-IoT standard?
Companies that plan to implement the Internet of Things globally or need to upgrade their existing 2G and 3G cellular networks have a variety of LTE IoT standards to choose from.
There are two new LTE IoT standards. NB-IoT stands for Narrowband Internet of Things; and LTE Cat M1, also known as LTE-M, is specifically designed for IoT. They have attracted widespread attention and are considered to be the technologies that will promote the deployment of next-generation cellular IoT. Operators have already begun to deploy these two standards.
The third option is most suitable for today’s global IoT deployment, the LTE IoT standard called Category 1 (Cat-1).
What is NB-IoT?
NB-IoT is a standard developed by the Third Generation Partnership Project (3GPP) as part of the 13th version of the cellular communication LTE standard. This is a low-power, wide-area network (LPWAN) technology that runs on a licensed spectrum and is designed for IoT devices with low bandwidth requirements.
Compared with other existing cellular standards, it is inexpensive, provides better indoor coverage, consumes less power, and therefore has longer battery life.
The uplink speed of NB-IoT in half-duplex mode is 66kbps and the download speed is 26kbps, which means that data can only flow in one direction at a time. It also has a delay of 1.6 to 10 seconds.
NB-IoT operates in a very narrow bandwidth (180 kHz) and can be deployed in the guard band part of the LTE network, that is, between channels in the unused part of the spectrum.
Therefore, it is best suited for simple IoT devices that require a small amount of intermittent data transmission and latency is insignificant.
Cellular technology provides remote support and strong signal penetration capabilities, so it is suitable for long-distance and indoor or underground use. But it cannot handle the switching of cellular towers, so it can only be used for fixed IoT applications.
Use cases for NB-IoT include smart gas meters, water meters, and electricity meters, smart city applications (such as smart street lights and parking sensors), and other remote sensing applications that do not send frequent or large amounts of data. These include HVAC controls, industrial monitors, and agricultural sensors that monitor irrigation systems and detect leaks.
What is LTE Cat M1?
LTE Cat M1, also known as LTE-M, is also a low-cost LPWAN technology developed by 3GPP as part of the 13th version of the LTE standard. It is a complementary technology to NB-IoT, with faster upload and download speeds of 1Mbps, and lower latency of 10 to 15 milliseconds.
LTE Cat M1 provides fast enough bandwidth to replace many current 2G and 3G IoT applications. It is different from NB-IoT in other aspects.
LTE Cat M1 supports cellular tower handover, so it can be used with mobile applications such as asset tracking and fleet management.
It also supports voice functions in IoT applications, such as medical alarm devices and home alarm systems, where people’s ability to speak is very important.
The LTE Cat M1 standard uses 1.4 MHz bandwidth and has enough throughput to transmit firmware, software, and other security updates to IoT devices (including a complete Linux operating system), which NB-IoT cannot do.
In addition, LTE Cat-M1 supports full-duplex and half-duplex, which means that companies can reduce power consumption and extend battery life by choosing half-duplex.
Good use cases for LTE Cat-M1 include wearable devices such as fitness wristbands, smartwatches, and automated teller machines (ATM), as well as asset tracking, health monitors, and alarms.
It also has some crossovers with NB-IoT, which can work with smart meters and industrial monitors.
What is LTE Cat 1?
LTE Cat 1 is designed for IoT devices that require medium and low bandwidth. It is part of the 8th edition of the 3GPP standard, so it is an older, but still current technology.
LTE Cat 1 (which has been widely adopted by operators worldwide) provides an upload speed of 5Mbps, a download speed of 10Mbps, and a delay of 50 to 100 milliseconds. In full-duplex mode, it uses up to 20 MHz bandwidth and supports tower switching.
LTE Cat 1 can manage low-power applications supported by NB-IoT and LTE Cat M1, but it can also support higher bandwidth requirements because it offers better performance and lower latency than its two similar products.
On the other hand, compared with NB-IoT and LTE Cat M1, LTE Cat 1 consumes more power and has a slightly shorter signal range.
LTE Cat 1 also supports voice and mobile IoT applications and also provides a good migration path for 2G and 3G applications (such as asset tracking, smart meters, and other remote sensors).
Other good causes include wearable devices, point-of-sale terminals, automated teller machines, retail kiosks, video surveillance, networked medical care, consumer electronic devices, and some vehicle telematics data processing.
It also supports shared mobile applications such as bicycle and scooter rental, as well as complex IoT devices such as digital signage and automated drone delivery.
The speed of LTE Cat 1 is not enough to meet the needs of future autonomous vehicles. In order to meet higher bandwidth requirements, the Cat-4 LTE standard has reached an upload speed of 50Mbps and a download speed of 150Mbps, which can better handle video surveillance and other real-time video applications, as well as car hotspots and car infotainment systems.
The future 5G cellular network will provide high-speed, low-latency communications to support autonomous vehicles, remote surgery in healthcare, and other high-bandwidth applications in the future.
Current status and limitations of NB-IoT and LTE Cat M1 (LTE-M)
Researchers predict that as more operators implement these two technologies in the next few years, they will steadily adopt IoT devices running on narrowband IoT and Cat-M1 networks.
By the end of 2025, NB-IoT and LTE Cat M1 are expected to account for 52% of all cellular IoT connections. It is predicted that by 2026, NB-IoT and LTE Cat M1 will account for 60% of 3.6 billion LPWAN connections.
Although NB-IoT and LTE Cat M1 provide many benefits, these two technologies currently have some limitations, that is, they are still emerging technologies and their global coverage are still limited.
Global coverage and roaming capabilities
Operators in North America, Europe, and Asia have begun to adopt these two technologies, but because NB-IoT and LTE Cat M1 are complementary technologies, some operators choose to support both technologies at the same time.
According to the Ericsson Mobile report, as of November 2019, nearly 25% of 114 service providers that have deployed NB-IoT or LTE Cat M1 have implemented these two services.
Although operators have made progress in adopting NB-IoT and LTE Cat M1, they have not yet been widely deployed globally. This limits the roaming function.
If your company has a specific IoT use case that requires roaming between operators on the LTE Cat-M1 network, it may not be possible because the adoption rate is still limited.
Is it really low power consumption? In fact, NB-IoT and LTE Cat-M1 consume less power than previous cellular technologies such as LTE Cat-1, 2G, and 3G networks.
The new LTE-IoT standard also includes some other power-saving features that can further reduce power consumption and extend the battery life of IoT devices. However, these features may not fulfill their promises, because operators may not fully support them.
NB-IoT and LTE Cat-M1 devices can sleep for a long time through the following two functions, power-saving mode (PSM) and extended discontinuous reception (eDRX).
With PSM, IoT devices using NB-IoT and Cat-M1 can sleep indefinitely and then wake up at a predetermined time to send and receive data.
Using eDRX, IoT devices can increase the paging cycle from the normal 1.28-second interval to 10.24 seconds. eDRX technology enables IoT devices to sleep for a predefined number of superframes or multiples of 10.24 seconds, so NB-IoT devices can sleep for up to three hours, while LTE Cat-M1 devices can sleep for up to 40 minutes.
Since the use of eDRX and PSM is not entirely determined by IoT devices, there is a potential limit on the power saved by eDRX and PSM. It depends on each specific carrier and whether each carrier supports all available low-power modes.
Operators may only adopt some low-power modes, which means that IoT devices may not be able to take full advantage of eDRX and PSM.
Why LTE Cat-1 is the best choice?
Companies that need to deploy the Internet of Things globally today should consider LTE Cat-1, because the two new alternatives, LTE Cat-M1 and NB-IoT, are not yet ready in most markets.
In contrast, Cat-1 is now available and widely supported by operators all over the world.
It has a low cost and is very popular in IoT deployments, and the price is similar to the current LTE Cat-M1 and NB-IoT modules.
Although it consumes more power than LTE Cat-M1 and NB-IoT, it does use quite low power and supports longer distances.
Power saving is very important. 2G and 3G are not low-energy technologies. With the closure of 2G and 3G networks, companies that need to upgrade their IoT deployments will find that LTE Cat-1 is more energy-efficient than 2G and 3G networks.
LTE Cat-M1 and NB-IoT are the future
3GPP plans to develop NB-IoT and Cat-M1 and merge them into 5G standards. LTE Cat-1 and LTE usually do not disappear anytime soon,
Operators are still in the early stages of 5G network construction. Therefore, LTE networks will maintain de facto standards for at least a few years.
Companies that need to deploy the Internet of Things globally or upgrade from 2G and 3G networks cannot wait for LTE Cat-M1 and NB-IoT as technology to expand and mature globally.
LTE Cat 1 is a viable and powerful solution that will provide the most extensive and thorough coverage for your current IoT needs today and in the next few years.
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