LTE-U vs WiFi: Differences, Bands, and Coexistence

This article clarifies the differences between LTE-U (LTE Unlicensed) and WiFi. It also details the LTE-U bands used in various regions, including the USA, Europe, Japan, and China. LTE-U is designed to work alongside existing LTE and WiFi networks, not to replace them.

LTE-U operates in the 5 GHz frequency band, which is part of the unlicensed ISM (Industrial, Scientific, and Medical) band. A key aspect is that LTE-U transmissions are designed to avoid negatively impacting existing LTE or WiFi installations. LTE-U devices adhere to the LBT (Listen Before Talk) protocol before transmitting, ensuring fair coexistence.

The primary goal of LTE-U is to offload traffic from both existing LTE networks and busy WiFi hotspots. The specifications are defined in 3GPP Release-12.

LTE-U Frequency Bands

The following table outlines the LTE-U frequency bands and their corresponding EIRP (Effective Isotropic Radiated Power) levels in different countries.

Both licensed LTE spectrum (700 MHz to 3.8 GHz) and the unlicensed 5 GHz spectrum can be combined using Carrier Aggregation to improve spectrum efficiency.

Here are some carrier aggregation modes supported in LTE-U:

LTE-U vs WiFi: Comparison and Coexistence

Here’s a comparison of LTE-U and WiFi and how they coexist:

• LTE-U operates at a higher energy level than typical WiFi devices, which minimizes interference. WiFi Access Points (APs) typically use 24 dBm, while WiFi Stations (STAs) use around 18 dBm. LTE-U EIRP levels for different bands are mentioned in the table above.

• LTE-U generally offers better spectrum efficiency compared to WiFi.

• LTE-U has a coverage range approximately two times greater than WiFi.

• LTE-U can provide a gain of up to three times compared to WiFi networks.