LTE-M or Long Term Evolution for Machines is a cellular connectivity technology designed to meet the long-range, low-data, low-power, and low-cost requirements of many Internet of Things (IoT) devices.
In this blog post, you’ll get a general overview of LTE-M, covering topics such as:
- The basics of LTE-M: what it is and it’s benefits and limitations
- The technical aspects of LTE-M
- Why LTE-M is the right connectivity solution for your use
- Industry applications of LTE-M
- What you need to do to get started with LTE-M: tools and further readings
Whether you are a tech enthusiast, a business owner, or simply curious about the future of connectivity, this article will explain how to successfully approach LTE-M for your IoT deployments.
Jump to topic
What is LTE-M?
LTE-M is a lower-bandwidth protocol developed by the 3GPP. Introduced on 3GPP’s Release 13 in 2016, LTE-M is a type of 4G cellular network that has since then been referred interchangeably in the industry with the following acronyms (we’ll keep referring to it as LTE-M in this guide for consistency):
- LTE-MTC (Long Term Evolution for Machine-Type Communication)
- LTE Category 1
- 3GPP Cat-M1
- LTE Cat M1
- eMTC (enhanced Machine-Type Communication)
LTE-M is a “Low-power, wide-area” (LPWA) technology standard specially designed for the IoT and Machine-to-machine (M2M) connectivity. It enables a wide range of IoT devices to stay connected, transmitting data efficiently and reliably.
Currently, there are around 20 LTE categories (more about the connection between LTE and LTE-M later), where LTE Cat-M1 and Cat-M2 are more common.
What are the benefits of LTE-M for IoT?
Many IoT devices are designed to utilize lower processing power, memory, and hardware requirements for use over long periods. They are also typically deployed in places where Wi-Fi, ethernet, or landlines are inaccessible, leaving cellular the only connectivity option. But cellular data can be pricey so data requirements must be kept low, and sent intermittently. By design, LTE-M works to solve these IoT issues.
1. Low power consumption
Optimized for battery life that can extend to several years.
2. Extended coverage
Designed to provide a deep coverage that reaches challenging locations such as underground or within buildings.
3. Less complexities
Deployment is straightforward and it is interoperable with LTE networks.
4. Scalability
Can be easily scaled up for a massive number of devices due to its efficient use of spectrum and network resources.
What are the limitations of LTE-M?
Because LTE-M is designed with IoT in mind, other devices or deployments might be better off with another kind of connectivity solution. Take note of these limitations to LTE-M when considering what connectivity solution to utilize for your solution.
- Bandwidth constraints: Inadequate for high data rate applications
- Incompatible with high-speed data transfer needs
- Not available in certain countries
How does LTE-M work?
To understand how LTE-M works, we need to backtrack and look at LTE first.
Consider LTE-M as a subset of LTE that is tailored specifically for IoT. In fact, LTE-M is adapted from LTE, which means the two share many similarities in architecture and protocols. LTE-M operates within the existing LTE network infrastructure and utilizes a number of protocols that are consistent with the standard LTE network.
LTE-M vs LTE: similarities
Below is a table that lists the network architecture and protocols adapted by LTE-M from the standard LTE network.
| LTE & LTE-M SIMILARITIES | |
| Network architecture | Protocols |
| User Equipment (UE): LTE-M devices or IoT modules that communicate with the network. | Control Plane: For signaling and control purposes, LTE-M uses the same LTE protocols for setting up the connection and maintaining the network (NAS, RRC, etc.). |
| eNodeB (Evolved Node B): The LTE base stations that manage radio communications with the UE. | User Plane: For data transfer, LTE-M leverages the standard LTE protocols (PDCP, RLC, MAC, and PHY layers). |
| Evolved Packet Core (EPC): The core network that manages high-level functions for the LTE network, including authentication, session management, mobility management, and routing of data to external networks. | Security: LTE-M inherits LTE’s security features, including mutual authentication, data integrity, and encryption. |
| MME (Mobility Management Entity): A component of the EPC that handles signaling and control functions, including UE authentication and security. | |
| SGW (Serving Gateway): It routes and forwards user data packets, while also acting as the mobility anchor for the data bearers when the UE moves between eNodeBs. | |
| PGW (Packet Data Network Gateway): This connects the LTE network to external IP networks, providing UE with IP addresses and QoS management. |
What are the key features of LTE-M?
LTE had to be modified in order to satisfy the unique needs of M2M and IoT. It is possible to argue that the elements that enable LTE-M to function better for connected devices are what set it apart from LTE. IoT applications typically call for less money, less power, and less data usage even with improved coverage. By utilizing these essential characteristics, LTE-M improves its IoT suitability.
The 7 key features of LTE-M for IoT
1. Radio access
LTE-M uses a modified version of the LTE radio protocols. It operates in licensed spectrum with a bandwidth as low as 1.4 MHz (compared to 20 MHz for regular LTE). This narrower bandwidth is sufficient for the small amount of data typically sent by IoT devices.
2. Power-saving features
LTE-M supports Power Saving Mode (PSM) and extended Discontinuous Reception (eDRX), which allow devices to sleep for extended periods of time and wake up only when needed to transmit data. This is critical for IoT devices that need to operate on a small battery for years.
3. Voice support
LTE-M can support voice communication over the LTE network using Voice over LTE (VoLTE), which can be important for certain IoT applications such as alarm systems or emergency services.
4. Frequency Division Duplex
LTE-M devices often use frequency-division duplex (FDD) operation and time-division duplex (TDD), which means they can transmit and receive but not at the same time. FDD can either be full- or half-duplex FDD (FD-FDD or HD-FDD). This reduces the complexity of the radio frequency (RF) front-end and saves power.
5. Single antenna
Typically, LTE-M devices use a single antenna for communication, which is less complex than the multiple antennas used for Multiple Input Multiple Output (MIMO) in standard LTE. This simplifies the device design and reduces costs.
6. Mobility
While LTE is designed for high-speed mobility, LTE-M supports lower mobility speeds. This is suitable for stationary or low-mobility IoT devices, which constitute a large segment of IoT applications.
7. Coverage enhancement
LTE-M has coverage enhancement modes that allow for better signal penetration in buildings and subterranean locations. This is achieved by repeating the transmission of data, which ensures that even in difficult-to-reach areas, the data can be reliably transmitted.
These adaptations make LTE-M more attractive for IoT use cases where devices need to send small amounts of data over long periods, in a wide range of environments, while conserving battery life and reducing hardware costs. Despite these differences, LTE-M benefits from being part of the LTE standard, ensuring good scalability, security, and compatibility with existing cellular network infrastructure.
Here’s a list that summarizes some key LTE-M protocols.
| FEATURE | LTE-M PROTOCOL |
|---|---|
| Deployment | In-band LTE |
| Minimum carrier bandwith | 1400 kHz |
| Data rate | Up to 1000 kbps |
| Transmission range | 5 km |
| Security | AES 256 |
| Modulation | QPSK, 16-QAM and 64-QAM |
| Duplexing | FD & HD (type B), FDD & TDD |
| Power saving | PSM, ext. I-DRX, C-DRX |
| Power class | 23 dBm, 20 dBm |
| Battery life time | 10 years |
| Link budget | 146 db |
LTE-M vs. other IoT connectivity options
Comparable to LTE-M is NarrowBand-Internet of Things, or NB-IoT.
- LTE-M and NB-IoT are both low power wide area network (LPWAN) technologies developed for IoT applications.
- LTE-M offers higher uplink and downlink speeds.
- LTE-M supports mobile devices through seamless handovers between base stations.
- LTE-M is generally better for applications requiring mobility and can handle over-the-air firmware updates more efficiently due to its higher bandwidth.
- NB-IoT might be preferred for static devices due to typically lower module costs and sufficient coverage for many use cases.
This table offers a quick overview on how LTE-M compares with NB-IoT. For a deep dive into the topic, you can refer to this guide.
Looking more granularly, check out this guide to see how LTE Cat 1 and LTE Cat 1bis stack up to each other.
💡 It’s important to keep in mind that depending on where you are in the world, NB-IoT could be more prominent than LTE-M (and vice versa). Onomondo offers global LTE-M coverage and NB-IoT coverage in Europe, Asia, and North America.
Choosing the right IoT connectivity technology
LTE-M is just one piece of the puzzle for IoT. And whether or not LTE-M, NB-IoT, or other network technology is right for your business, connectivity shouldn’t be an afterthought. In fact, there are many things to be gained when starting with connectivity when designing your IoT device.
But what things do you need to consider when choosing the most suitable connectivity solution for your business? Here are some things to look out for:
1. Consider the size of your device
Determine the size limitations for your IoT device and choose a connectivity solution that fits within those constraints.
2. Evaluate coverage
Assess the coverage provided by different connectivity options. Consider factors like urban and rural coverage, limitations in certain countries, and indoor reliability.
3. Assess power and battery life
Understand the power consumption of different connectivity solutions. Compare power consumption per update for sensor devices and devices with GPS functionality.
4. Consider data and throughput capability
Evaluate the payload sizes and update rates offered by different connectivity options. This will impact the amount and frequency of data you can transmit.
5. Factor in price
Consider the cost of the IoT connectivity solution. Balance the upfront costs of devices and infrastructure with the ongoing expenses for connectivity.
For expert advice on selecting the right connectivity solution for your IoT business, the CEO of LightBug, Chris Guest, shared his top tips for choosing the best IoT connectivity solution. Chris also highlighted the need to prioritize the non-negotiable aspects of your business needs before making tradeoffs.
How can LTE-M work for your IoT business?
The global industrial IoT market is expected to grow to US$1.5 billion by the 2030s, according to industry research. LTE-M can help drive industry growth as it delivers a combination of wide-range, low-cost, and reliable connectivity for IoT solutions.
From smart meters and wearables to asset tracking and smart agriculture, LTE-M provides businesses with the tools to innovate and stay competitive. IoT applications are innovating in many industries and below are some examples where LTE-M is especially beneficial.
IoT use cases for LTE-M
Asset tracking and logistics
Whether it’s indoors or underground, across roads, or out in the sea (such as the case for Maersk) ensuring continuous monitoring and efficient logistics management are non-negotiable for IoT asset tracking and logistics deployments
LTE-M has long-range capabilities and low power consumption making it ideal for real-time tracking and monitoring of assets across wide areas without frequent battery replacements. What’s also great about LTE-M is that it can provide reliable connectivity in challenging environments.
Smart agriculture
Farming is at the cusp of industry-wide transformations. Smart agriculture facilitates proactive decision-making, optimizing resource utilization, and improving crop management. LTE-M can enable efficient and cost-effective monitoring of crops, soil conditions, and equipment.
Farmers can set-up systems to remotely monitor and control irrigation systems, track environmental parameters, and receive real-time alerts about potential issues, such as equipment malfunctions or extreme temperature. This will allow farmers to focus on other important aspects of their business and help with optimizing land management.
Remote monitoring and control
Because of LTE-M’s low latency and excellent dependability, equipment may be remotely controlled and automated, which facilitates effective management and lower maintenance costs. It may be used to ensure early defect or anomaly detection in vital infrastructure, such as pipelines, utilities, and industrial equipment.
When running an intelligent plug-and-play sensor platform, Consibio utilized LTE-M as a key component to make sure they have stable connectivity for devices underground in sewage systems. You can read more about how Consibio tackles remote monitoring and control with an IoT solution.
Healthcare and wearable devices
IoT for healthcare is one of the fastest growing verticals for IoT projects. LTE-M’s wide coverage and reliable connectivity support remote patient monitoring and telemedicine applications. This enables real-time transmission of critical health data, allowing personalized healthcare that enables healthcare professionals to continuously monitor patients remotely and provide timely interventions.
LTE-M’s low power consumption also ensures prolonged battery life for wearable devices, enhancing user experience and reducing the need for frequent recharging.
Smart cities and infrastructure
Remote diagnostics, low-cost connectivity, and adaptability requirements are crucial for IoT deployments for smart cities and building the infrastructure of tomorrow. In the case of Aguardio, an innovative water-saving IoT solutions company, LTE-M means they can meet technical and logistical requirements for building efficient IoT building management systems. Read more about Aguardio’s story, here.
→ Learn from other IoT businesses and how they delivered market-leading connected solutions with Onomondo. See Customer Stories
Is LTE-M future-proof?
LTE-M is designed to be forward-compatible with both existing LTE and future 5G New Radio (NR) systems. Most devices with LTE-M are firmware upgradable to their 5G versions, indicating a clear path toward 5G integration.
Additionally, 3GPP is studying ways to connect LTE-M (and NB-IoT) to the 5G core network, further confirming their trajectory towards being part of the 5G ecosystem. This means that the transition to 5G will allow LTE, NR, NB-IoT, and LTE-M to use the same core network, unlike the shift from 2G/3G to 4G which required different core networks.
→ Interested to learn more about future-proofing cellular IoT devices? Watch this on-demand webinar to know more.
Getting started with LTE-M
After assessing the specifications of your IoT product and LTE-M stood out as the rightful connectivity option for your needs, what’s next? When getting started with LTE-M for IoT, also factor in these two things: location and hardware.
Hardware
Designing an IoT device geared for LTE-M connectivity usually requires a chipset, module, and the end-devices or embedded modules. IoT or M2M SIM cards are also needed to establish connectivity for the device. IoT device development is a completely different topic (watch out for that one on our blog) so we’ll just briefly touch on it in this guide.
In a nutshell, testing, approvals, and certifications (among other things) are needed when designing custom devices down to the chipset level. This means a lot of planning and engineering — and the costs can be significant.
Make sure the ROI is worth it if treading down this level of device customization. Modules that are pre-built with embedded systems are available and are used by many IoT businesses. One example of such hardware is Nordic Semiconductor’s low power nRF9160 System-in-Package (SiP) with an integrated LTE-M/NB-IoT modem.
→ Read up on how Onomondo and Nordic Semiconductor partnered up to drive device efficiencies with the SoftSIM.
LTE-M SIMs
Once you’re ready to start testing, our LTE-M SIMs for IoT are available in every form factor to fit your device requirements.
We offer a free trial for LTE-M SIMs with access to over 100 LTE-M networks globally.
Start testing Onomondo for free
Ready to experience next-generation IoT connectivity? Create an account, explore the platform, and start testing Onomondo’s IoT SIM cards for free.
Build your LTE-M network list
Manage your LTE-M networks across the world using our free LTE-M network coverage list. You can also download the full network list so you can plan the coverage needs for your IoT deployment.
Resources
- LTE-M communication for low-powered IIoT: An experimental performance study (2023). Eddy Bajic, Kais Mekki, Clement Rup. https://hal.science/hal-04222955/
- LTE-M Deployment Guide to Basic Feature Set Requirements (2019). GSMA. https://www.gsma.com/iot/wp-content/uploads/2019/08/201906-GSMA-LTE-M-Deployment-Guide-v3.pdf
- Security Features of LTE-M and NB-IoT Networks (2019). GSMA. https://www.gsma.com/iot/wp-content/uploads/2019/09/Security-Features-of-LTE-M-and-NB-IoT-Networks.pdf
