What Frequency is LTE Unlicensed?
LTE (Long-Term Evolution) can operate on both licensed and unlicensed frequencies. Unlicensed frequencies are those that can be used by any device without the need for a specific license, unlike licensed bands which are allocated by regulatory bodies for exclusive use by mobile network operators. LTE can operate on unlicensed spectrum through technologies like LTE-U (LTE Unlicensed) and LAA (License-Assisted Access). Let me explain more about the unlicensed frequencies used by LTE.
LTE Unlicensed Frequencies
Unlicensed frequencies used for LTE are primarily in the 5 GHz band, which is a popular frequency range for Wi-Fi and other wireless communications. These unlicensed spectrum bands are part of the broader 5 GHz range and are used to offload traffic from licensed LTE bands, helping to improve network capacity and performance, especially in areas with high user density.
Key LTE Unlicensed Bands
- 5 GHz Band: The most commonly used unlicensed spectrum for LTE. This band is shared with other technologies like Wi-Fi, and LTE networks use it to boost download speeds and overall capacity by combining licensed and unlicensed spectrum (a method called carrier aggregation).
- Licensed-Assisted Access (LAA): LTE-U is enhanced by LAA, which allows LTE to use the unlicensed 5 GHz band in conjunction with licensed bands. By using LAA, LTE can achieve higher speeds and more efficient use of the available spectrum. LAA makes use of the 5 GHz band, but it must also respect existing users, like Wi-Fi, by using listen-before-talk (LBT) protocols to avoid interference.
Benefits of LTE Unlicensed
Using unlicensed spectrum for LTE has several advantages:
- Improved Capacity: By adding unlicensed spectrum to the mix, LTE networks can offload more traffic and enhance network capacity, especially in high-traffic areas.
- Higher Data Rates: The use of unlicensed spectrum can help achieve higher speeds, especially when combined with carrier aggregation techniques, which combine both licensed and unlicensed bands.
- Efficient Spectrum Use: LTE can take advantage of unlicensed spectrum without requiring additional spectrum allocations from regulatory authorities, making it a cost-effective way to meet growing demand.
Challenges of LTE Unlicensed
While using unlicensed spectrum offers benefits, there are also challenges:
- Interference with Wi-Fi: Since the 5 GHz band is shared with Wi-Fi, LTE may cause interference with existing Wi-Fi networks, especially if the LTE system is not carefully managed to avoid competing for the same channels.
- Fair Spectrum Sharing: LTE systems using the unlicensed 5 GHz spectrum must follow regulations that ensure fair sharing of the spectrum with other technologies like Wi-Fi. This is typically done by using Listen-Before-Talk (LBT) protocols, but it adds complexity to the network management.
Conclusion
In summary, LTE can use the 5 GHz band, which is an unlicensed frequency, to improve network capacity and performance. Technologies like LTE-U and LAA make use of unlicensed spectrum to offload traffic and increase data rates, especially in crowded areas. While it offers several benefits, such as higher speeds and better capacity, LTE unlicensed also faces challenges, including potential interference with Wi-Fi and the need for fair spectrum sharing.