Wireless network providers use a number of cellular frequency bands to deliver 4G LTE voice and data services to their users. LTE technology – or Long-Term Evolution – is a wireless broadband communication standard, and 4G LTE – the fourth generation of cellular communications – represents one of the more recent upgrades to the core LTE network. LTE and LTE upgrades make it possible for customers to make phone calls, send and receive text messages, access the Internet, and enjoy better multimedia and data transfer capabilities.
Most mobile and cellular devices are designed to work with specific frequency bands. Here we talk about different LTE frequency bands and the various cellular connectivity protocols used in the telecom sector.
LTE Bands Explained
The LTE standard uses radio waves to transmit data. Radio waves can vary in length from between one millimeter to over 100 kilometers, and they can also have different frequencies. Frequency is measured in Hertz (Hz), and it represents the number of complete cycles a wave performs per second.
LTE bands are discrete slabs of frequencies that are used for telecommunications. So, for example, LTE Band 1 is stated to have a frequency of 2100 MHz (megahertz), but it actually uses frequencies between 1920 and 1980 MHz to uplink data and frequencies between 2110 and 2170 MHz to downlink data. In other words, the single number used to denote band frequencies is somewhat misleading, and LTE bands contain a range of frequencies. Furthermore, bands and the frequencies they contain can vary from one geographic region to the next. This is known as allocation and is normally done by local governments.
Next, wireless spectrums can be either paired or unpaired. Paired spectrums allocate two distinct and equal frequency bands for communications. One is assigned to downlink from a base station to a mobile device, and the other is assigned to transmitting uplink data. This is known as Frequency Division Duplexing, or FDD. This contrasts with the unpaired spectrum that provides a single band that is used for both downlink as well as uplink, which is known as TDD, or Time Division Duplexing. Think of a phone connection in which both parties can talk at the same time versus a walkie talkie connection that allows only unidirectional data transfer at any given point in time. The phone connection is an example of FDD, while the walkie talkies are an example of TDD.
LTE Infrastructure and Data Transmission
Some of the key goals of LTE networks is to deliver as short a transmission time as possible, along with high throughput (which is the amount of data that can be transferred), low latency (which is a measure of the delay between sending and receiving data) and security. Telecommunication services that come with these fundamental characteristics are typically comprised of a base station (which is a radio receiver or transmitter and can also act as a gateway between wired and wireless networks) connected to a core network.
Each base station has a predetermined coverage area and can communicate directly with approved or designated equipment and devices within that coverage area. If a device or sensor moves from an area served by one base station to an area served by another one, a simple handover transfers control of the session or the connection from the first base station to the next.
The efficiency with which LTE networks do all of the above is one of the reasons it has gained so much popularity as the global telecom standard of choice. However, many significant challenges remain.
- Signal overheads, a large number of connections, overlapping control of data sessions, and a general rise in data traffic can increase latency or outages.
- Backward compatibility, functionality testing, and interoperability testing between devices and upgraded core networks can be challenging to perform.
- Green operations can be challenging to maintain, given the dramatic growth of mobile users and the exponential rise in data requirements.
Carrier aggregation, in which the available spectrum in a given frequency band is bundled to a particular telecom operator, can help, but the equipment used by consumers must be compatible with different bands used by their operator, and multiple reception chains can lead to higher power consumption during transmission. In any case, the high data transfer rates powered by LTE bands come at a cost. The tradeoffs between power consumption, low latency, and high data throughput are long-standing challenges in the telecommunications space.
Depending on the use case at hand, LTE may or may not be ideal for your telecommunications needs. The challenges above provided some of the impetus for the development of NB-IoT, or narrowband IoT. NB-IoT was designed to consume less power and extend device battery lifetimes while connecting more devices and keeping data transmission to the bare minimum to lower costs and maintenance downtimes. It has gained considerable interest in industries such as agriculture, supply chain, logistics, and transportation.
LTE bands are an essential part of mobile phone and mobile device functionality, and they determine how operators provide services to their customers. Understanding LTE frequency bands is essential for two key reasons. Firstly, the data transfer and operational costs that are associated with running on a particular band are a vital part of any business strategy. Secondly, understanding LTE frequency bands will make it easier for you to determine which network – and the various devices that can run on a given network – are best suited to your business needs. If a given LTE solution does not serve your business needs, NB-IoT can offer tangible benefits, and it would be worth exploring your options to see which deployment is best for you.
This is what a Kajeet Solutions Engineer can do for you. Our team can help you plan, set up, and run a mobile and connectivity solution that is custom-designed for your needs and helps streamline and improve your business operations based on your desired end goals. Please contact us here for a consultation with a member of our team.