Although the term 4G is widely used in the telecommunications world, LTE isn’t as commonly understood. It is, however, an integral part of mobile telecommunication as we know it today. Understanding these factors will help you prepare yourself for what lies ahead. In this article, I have prepared a detailed guide on mobile LTE and its importance for 5G connectivity. We shall also discuss some technical and historical aspects of LTE connectivity.
What is LTE connectivity?
LTE, which stands for Long Term Evolution, is a telecommunication standard that falls under the broadband category. It was designed to cater to mobile phones, tablets, IoT devices, and other enterprise applications, which require high-speed Internet access, among other connectivity options.
Because it succeeds 3G in the chronology of telecommunication standards, LTE is often referred to as 4G LTE. On many occasions, the terms “4G” and “LTE” are frequently used interchangeably. Compared to previous standards like 3G, the LTE telecommunication standard offers significant boosts in network speed and efficiency.
As a customer, you may have found the term LTE next to the reception icon on your smartphone. It happens when your smartphone is connected to a 4G LTE network. Here’s a quick table comparing LTE connectivity to previous options, such as 3G.
Feature | 3G (Past) | LTE / 4G (Present Standard) |
|---|---|---|
Primary Focus | Voice calls with some internet. | High-speed mobile data & video. |
Architecture | Circuit-switched (mostly). | Packet-switched (All-IP). |
Latency | High (100ms+). | Low (30-50ms). |
Max Speed | ~42 Mbps (HSPA+). | ~300 Mbps (Standard LTE). |
Please note that the actual speeds from these connections depend on several factors, including congestion, weather conditions, and device type.
In addition to improving speed and performance, LTE connectivity also offers several other benefits:
- LTE was the first telecommunication standard capable of managing IoT devices. Multiple variations of LTE, such as LTE-M, have been made for these purposes.
- LTE has also improved the quality of voice calls, thanks to VoLTE. It is also a reason people now benefit from global roaming. It was impossible during the time of GSM/CDMA.
- You also get better power efficiency when connected to LTE networks. In contrast, 3G networks were once known for their high battery consumption.
- LTE networks also support simultaneous calls and mobile data, further enhancing convenience. The call setup time is also less on LTE compared to its predecessors.
Overall, LTE connectivity is indeed a significant milestone in the history of telecommunications standards.
How Does LTE Work?
We shall now see how LTE works.
Long-Term Evolution utilizes several technologies to provide the advantages we discussed earlier. Here are a few of them:
Radio Access Mechanism
LTE utilizes orthogonal frequency-division multiple access (OFDMA) and single-carrier FDMA (SC-FDMA) radio access mechanisms for the downlink and uplink, respectively. This combination offers the best speeds while minimizing interference. Even when handling high throughput, the system ensures maximum power efficiency on devices.
Packet Switching
While a 3G network utilizes circuit switching for voice services, LTE employs a different approach. It utilizes packet switching and IP-based routing to ensure that data is delivered to its intended destination. Packets from your device travel to the Internet using the LTE platform itself. Because routing is based on IP addresses, the LTE system also minimizes latency.
In other words, LTE networks treat everything as data, rather than creating a distinction between data/voice. This is a key reason why VoLTE is significant when making calls using a 4G network. This approach can offer higher-quality audio content with minimal infrastructural resources.
MIMO
LTE also utilizes the Multiple Input Multiple Output (MIMO) approach. Instead of relying on a single antenna, LTE networks leverage multiple antennas on towers as well as on LTE-enabled devices. As a result, a single stream can handle more data, increasing the overall speed you get from an LTE connection. Once again, the ultimate performance will depend on your device.
Carrier Aggregation
Carrier aggregation is also a characteristic of LTE connectivity. This technology ensures that you get the best speeds by combining multiple component carriers, also known as CC, across different frequency bands. For instance, a system may combine frequencies such as 800 MHz, 1800 MHz, and 2600 MHz to create a larger system that can throughput more data simultaneously.
All these components work together to transform LTE networks into something that caters to the increasing demands for bandwidth, performance, and latency.
LTE’s Architecture
Let’s look at the LTE architecture.
Four major components are essential for the LTE network to function correctly. Here’s an overview of those four components:
#1 User Equipment
User Equipment is at the receiving end of the LTE network. Devices like your smartphone, Wi-Fi routers, and IoT devices would be included in the UE category. These devices will use their radios to connect to the LTE network and access the provided information.
#2 E-UTRAN
E-UTRAN, which stands for Evolved UMTS Terrestrial Radio Access Network, is the foremost component of the LTE network. This radio access network is what connects user devices to the core network. The most crucial part of E-UTRAN is the LTE base station, which handles scheduling, QoS, resource management, and encryption.
#3 EPC
In the next section, we have Evolved Packet Core, commonly referred to as EPC. EPC is the core network of the LTE system, and E-UTRAN serves as the intermediary between EPC and the User Equipment. This system comprises three parts. While the Mobile Management Entity (MME) handles handovers, authentication, and mobility, the Serving Gateway (S-GW) manages packet routing and establishes user data sessions. The third component, namely the Packet Data Network Gateway (P-GW), connects the system to another network, such as the Internet. Without P-GW, data over LTE would not work.
#4 IMS for VoLTE
Considering that voice over LTE is a common feature these days, most LTE systems also contain a component called IP Multimedia Subsystem. This component ensures that voice call data is converted into data packets and transferred over the same protocol.
It is worth noting that the exact architecture of the LTE system would vary based on the requirements and the environment. For instance, LTE-M may require additional components, as this network is designed and optimized for IoT devices.
The Evolution of LTE Technology
I cannot possibly cover the entire history of the LTE technology for obvious reasons. Instead, we shall discuss some critical milestones in the evolution of LTE technology.
Release 8: Baseline
Release 8 is considered the baseline for LTE networking, having been launched in 2009. Networks during this period were just in the establishing phase and offered peak download speeds of 100 Mbps and upload speeds of 50 Mbps. It utilized OFDMA, SC-FDMA, and MIMO, but also achieved an improved latency of 50 to 30 milliseconds. This was the base from which 4G networking grew.
Release 10-12: Gigabit 4G
In the following years, LTE saw the release of 10-12, in which the system was improved to accommodate the increasing needs for speed and performance. One of the significant enhancements during this period was Carrier Aggregation, which increased speeds to a maximum of 1 Gbps, and an enhanced portion of MIMO, ensuring that multiple devices could rely on the network without compromising speeds.
They also included better relay nodes and coordinated multipoint systems. As a result of these changes, 4G LTE networks became comparable to fiber connections at the time, marking the first steps toward mobile broadband and the Internet of Things.
Release 13-14: Pre-5G
The pre-5G phase of LTE happened during releases 13 to 14, and these features made 4G LTE somewhat comparable to 5G capabilities. For instance, it introduced 250 QAM downlink and 64 QAM uplink, resulting in improved efficiency for both directions.
Similarly, we saw the rise of massive MIMO building blocks and support for unlicensed spectrum. LTE was able to rely on these unlicensed 5 GHz bands to enhance performance within urban areas. There were also IoT-specific changes to the system, including the introduction of LTE-M and NB-IoT.
This phase of LTE networking also saw several attempts to reduce latency to as low as 10 milliseconds.
Release 15: 5G and After
The world of telecommunications has reached the 5G phase, but LTE is not yet obsolete.
You may already be familiar with the Non-Standalone Mode of 5G networks. LTE connections are integral to this system. 5G has not actually replaced what 4G LTE was building. Instead, it works as an anchor that the 5G connection can fall back on.
We will discuss this further in a bit.
Difference Between 4G LTE And 5G
Let’s now talk about the differences between 4G LTE and 5G.
Parameter | 4G LTE | 5G |
|---|---|---|
Peak Data Rate | 100 Mbps to 1 Gbps (LTE-A) | 1–20 Gbps depending on band |
Typical Latency | 20–40 ms | 1–10 ms |
Spectrum | Mostly sub-3 GHz | Low-band, mid-band, mmWave |
Device Density | ~100,000 devices/km² | ~1 million devices/km² |
Architecture | EPC, centralized | Cloud-native, service-based, network slicing |
Energy Efficiency | Moderate | Designed for high energy efficiency and longer IoT battery life |
Mobility Support | Good (up to ~350 km/h) | Enhanced (up to ~500 km/h in some profiles) |
Key Use Cases | Mobile broadband, VoLTE, basic IoT | eMBB, mMTC, URLLC, industrial IoT, autonomous systems |
Reliability | High but not deterministic | Ultra-reliable, mission-critical capable |
As you can see, 5G brings massive improvements in terms of performance, speed, and throughput. While its maximum speeds are theoretical, 5G connections still can bring speeds between 1-2 Gbps. 5G connections are also more reliable than 4G LTE connections in most cases, especially when it comes to latency-intensive tasks like gaming, video-conferencing, etc.
The cloud-native infrastructure of 5G also supports an unprecedented number of devices. You can utilize 5G for an incredible variety of use cases, including autonomous mobility, smart grids, AR/VR, and the growing set of AI-based applications. However, all these still don’t mean that 5G is independent of LTE.
Why LTE Networks Matter for IoT and 5G
Here is how 5G and IoT continue to benefit from LTE networks.
LTE as an Anchor for 5G Deployment
Earlier deployments of 5G networks were in the Non-Standalone method, also known as NSA. It means the 5G radio base stations still depend on LTE networks for control signaling. It is also a way of anchoring in the sense that the network can fall back onto LTE when 5G doesn’t work. This has been crucial and remains the case in many sectors where standalone 5G networks are still being built.
Enhanced Coverage Options
It is estimated that 90% of the volt has existing connectivity for LTE networks. For this reason, LTE becomes a backup option for 5G networks and IoT connections because LTE is already optimized to run IoT devices with ease. The predictable performance that you get from the LTE infrastructure and ecosystem also matters significantly when deploying something as significant as IoT.
LTE for Internet of Things
LTE networks are further optimized for IoT systems, particularly for LTE-M. This particular version has been optimized for low-power devices that offer wide coverage. When discussing wearable devices and asset trackers like AirTags, you can benefit from LTE connectivity. When 5G alternatives are being launched, they do not actually replace LTE.
In addition to these, hybrid systems (LTE + 5G) and private networks can also benefit from LTE.
What Is Private LTE?
Private LTE is a type of LTE network that is specifically designed for a private organization, rather than the general public. This network could be optimized according to the specific requirements. For instance, private LTE networks will provide the organization with advanced access control. They also offer improved network latency and scalability.
Multiple industries, including automation and robotics, can benefit from a private LTE connection. Some other use cases include logistics hubs, enterprise campuses, and the energy sector, among others. A private LTE connection benefits from all the features we discussed, but the deployment costs would be higher, as resources are exclusive.
Wrapping Up
I believe you have a better understanding of LTE networks and their continuing role in 5G and the future of telecommunications. It becomes clear that LTE is here to stay, and it may acquire many sub-identities in the years to come.
