Which are the main LTE standards for the unlicensed bands?
Let’s dive into LTE standards for unlicensed bands. If you’re familiar with the fundamentals of LTE, you might know that LTE typically operates on licensed spectrum. However, with the growing demand for high-speed mobile internet, operators started using unlicensed spectrum to enhance capacity and improve network efficiency. This brings us to the LTE standards for unlicensed bands.
The LTE standards for unlicensed bands are designed to help operators utilize unlicensed frequency bands for LTE services, without interfering with other technologies like Wi-Fi. This allows mobile operators to offload traffic, increase capacity, and deliver faster speeds, particularly in dense environments where spectrum congestion is common. There are two main LTE standards for unlicensed bands:
- LTE-U (LTE Unlicensed): LTE-U allows LTE services to operate in unlicensed spectrum bands, typically in the 5 GHz range. This enables operators to supplement their licensed spectrum with unlicensed bands to increase network capacity. LTE-U works by using a technique called carrier aggregation, where licensed and unlicensed spectrum are combined to improve performance and coverage.
- LAA (Licensed Assisted Access): LAA is another LTE standard that uses unlicensed spectrum to deliver better performance. It operates in the 5 GHz band and relies on carrier aggregation to combine both licensed and unlicensed spectrum. One important feature of LAA is the use of the Listen-Before-Talk (LBT) mechanism, which ensures that LTE does not interfere with Wi-Fi or other technologies using the same unlicensed band.
The key difference between LTE-U and LAA lies in the way they operate in the unlicensed spectrum. While LTE-U allows LTE to transmit in unlicensed bands without necessarily using the LBT mechanism, LAA strictly adheres to LBT to prevent interference with other devices that also use the unlicensed band (such as Wi-Fi). The LBT mechanism ensures that LTE does not transmit on a channel if the channel is already in use by another technology.
These LTE standards for unlicensed bands bring several benefits, including:
- Increased Capacity: By utilizing the unlicensed spectrum, operators can offload traffic from the licensed spectrum, effectively increasing the overall network capacity.
- Better Performance in Dense Areas: Unlicensed spectrum provides additional bandwidth, which is especially useful in areas with high network traffic, such as urban environments or large public events.
- Cost Efficiency: Since unlicensed spectrum is available for public use, it offers a more cost-effective solution compared to acquiring additional licensed spectrum.
In previous articles, we’ve touched on LTE carrier aggregation and its role in enhancing network performance. By adding unlicensed spectrum into the mix, LTE-U and LAA take carrier aggregation a step further, providing even more flexibility and higher speeds. These technologies demonstrate how LTE can evolve to meet the growing demands of modern mobile networks.