The concept of LTE inspires a number of questions. What Is LTE? What is LTE data? And, is LTE the same as 4G? In brief, while LTE is not technically the same as 4G, its evolution has occurred on 4G networks. LTE data is transferred faster and with lower latency, as we will explore in this section and the next.
For most consumers, their first introduction to “LTE” was likely when they noticed those letters in the corner of the screen on their smartphone and asked, what does LTE mean on my phone? For mobile handsets, it simply means that the phone is connected to the carrier’s 4G LTE network.
At Digi, we are focused on the commercial and industrial use cases of 4G LTE and 5G, as our customers are distributed across the enterprise, industrial, transportation, government and medical landscapes. So the remainder of this article is devoted to the discussion of the LTE meaning and outlook in that context.
When Long-Term Evolution (LTE) was first introduced in 2008, it defined a new cellular access network with high spectral efficiency, high peak data rates, short round trip time as well as flexibility in frequency and bandwidth. It signifies an evolving level of performance as the capabilities of cellular hardware, software and network technology — such as speed, latency, battery usage and cost efficiency — are optimized and improved over time. As one industry observer noted about LTE, “It isn’t as much a technology as it is the path followed to achieve 4G speeds.”
It is important to know that as succeeding generations of cellular technology are introduced, previous generation(s) will remain in service, often coexisting for a decade or more with the newer technology.
What LTE means for those purchasing and deploying LTE technology today is that they can deploy a wide range of devices in an LTE network with confidence that their deployment will remain viable for many years to come. This is especially important as older 2G and 3G networks are sunsetting to allow that spectrum to be used more efficiently. Looking at LTE vs. 3G, those with device deployments based on pre-4G networks must migrate to 4G or 5G without delay. If you already have 4G, you’re future-proofed through the useful lifespan of your products.
LTE technology has delivered multiple benefits worldwide:
LTE improves upon the functionality and performance of older networks. This brief LTE description from Keven Sookecheff provides an excellent LTE overview to help understand how LTE works:
LTE is a redesign of the 3G standard to satisfy the demand for low latency data transmission. The redesign includes:
Here are a few important facts to know about how LTE works at a high level:
When 4G evolved from its 3G predecessor, the actual network architecture involved small incremental changes. The following diagram, from our 5G Network Architecture blog shows how LTE works from an architecture perspective:
In the 4G LTE, User Equipment (UE) like smartphones or cellular devices, connects over the LTE Radio Access Network (E-UTRAN) to the Evolved Packet Core (EPC) and then further to External Networks, like the Internet. The Evolved NodeB (eNodeB) separates the user data traffic (user plane) from the network’s management data traffic (control plane) and feeds both separately into the EPC.
Approximately every decade the Radiocommunication Sector of the International Telecommunications Union (ITU-R) and its partners define a new generation of requirements for speed, connectivity and spectrum for the worldwide mobile communication systems. Older generations of technology are retired or sunsetted periodically so that more data can be carried over the same spectrum and more devices can share the available spectrum.
The ITU-R standards reflect advances in technology and timelines for their adoption are established to meet new application and industry needs. Another organization called the 3rd Generation Partnership Project (3GPP) takes the ITU-R requirements and writes technical specifications that are bundled into a series of releases.
Timeline of releases by 3GPP shows key milestones in the evolution of LTE technology. Source: Qualcomm
Here is a brief chronology of key LTE development milestones and related LTE technology:
It's important here to also mention “Private LTE” or “Private Mobile Networks”, which offer a deployment option for LTE technology. While LTE is primarily used in public networks, Private LTE networks are small wireless networks that operate using the same protocols and technology as public LTE, using licensed, unlicensed or shared spectrum to deliver coverage for cellphones and other devices. Mobile network operators (MNOs) can license spectrum and then deploy an isolated Private LTE network on that spectrum.
Private LTE networks are an affordable solution for geographically defined sites such as remote oil fields or mining sites, or in confined areas such as in large factories or seaports. Private LTE is also seen in airports, sports stadiums and on college or corporate campuses. These various use cases benefit from the near-constant uptime that is possible with Private LTE.
Citizens Broadband Radio Service (CBRS) is a version of Private LTE in the U.S. that uses shared spectrum in the 3.5 GHz band (B48). CBRS, which addresses similar use cases than Wi-Fi, is becoming increasingly popular with Enterprise and Industrial customers that want more control over their wireless network. It offers a cost-effective networking option for remote worksites and rural areas with poor or no public cellular reception.
3G networks began rolling out commercially in 2002, gradually augmenting and later replacing the earlier 2G network protocol. LTE functionality builds on some of the underlying 3G technology and functions as an enhancement to 3G.
Here are some of the major differences between 3G and LTE:
The terms “4G” and “LTE” are often used interchangeably and “4G LTE” is seen frequently in industry literature. While carrier marketing sometimes suggests that 4G LTE is an enhanced version of 4G, 4G LTE actually refers to devices and networks that are evolving from the slower 3G standard to full 4G speed and throughput capability. 4G LTE covers the entire range of download speeds from 3G’s 10th of Mbps to 4G’s 100th of Mbps.
“4G” refers to the generation of technology, while “LTE” is the methodology for evolving that generation over the course of multiple releases from 3GPP that explicitly set out the technical steps that deliver better performance and more functionality. This incremental process keeps devices compatible and enables technology to carry forward in a smooth transition from one generation to the next.
LTE networks are used heavily by Internet of Things (IoT) solutions to connect machinery and equipment and enable them to send and receive data. While the IoT existed before the introduction of LTE-level connectivity, the higher speed and throughput of LTE made it possible for IoT systems to control larger and more complex systems with greater precision.
IoT solutions are used in virtually all industries. The following are some of the most widely deployed examples of LTE-enabled IoT:
Continuing LTE connectivity is essential for the smooth rollout of 5G networks. LTE and 5G networks will co-exist for at least a decade until the full 5G infrastructure is built out and LTE will be critical to providing fallback connectivity in areas with limited 5G coverage. Early on, LTE will also be significantly cheaper than 5G for most applications.
From an infrastructure perspective, almost all 5G networks will be initially rolled out in “5G non-standalone” (5G NSA) mode. Initial 5G devices have a radio built in that supports both 4G LTE and 5G. The device will connect to the 4G LTE network first, and uses a 5G network for additional bandwidth, if one is available. Eventually, the roles will be reversed as 5G networks are maturing, and devices will only connect to the 5G network in “5G stand-alone” (5G SA) mode, and are then able to take full advantage of 5G technology.
Here are some FAQs about the important ways that LTE will support 5G:
Additionally, LTE provides essential physical network infrastructure for 5G. One industry expert noted that “Early 5G networks … require a 4G LTE control plane [a network element responsible for routing traffic] to manage 5G data sessions.”
LTE is a key stepping-stone in the development of wireless connectivity, for consumers as well as for commercial and industrial applications. Even as industries and IoT developers discover the extraordinary possibilities presented by 5G, it’s reassuring to know that LTE technology provides a proven — and often lower cost — bridge to that future.
Digi offers complete cellular solutions using 4G LTE, LTE Advanced and 5G technologies to support your organization in future proofing your deployment of connected devices, with robust, integrated security, sophisticated software, and industry-leading cloud and edge management tools.
Need support for your migration to new technology? Learn about LTE and 5G Migration Solutions. Digi can support any aspect of your project as you prepare your organization for the sunset of 2G and 3G networks and for the world of LTE, 5G and beyond.
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