LTE operation in unlicensed spectrum (5 GHz) using Carrier Aggregation with licensed anchor.
Description
Licensed Assisted Access (LAA) enables LTE to operate in the unlicensed 5 GHz spectrum band while using a licensed carrier as the primary cell anchor. This combines the reliability of licensed spectrum with the additional capacity of unlicensed bands.
LAA uses Listen Before Talk (LBT) mechanism to ensure fair coexistence with other unlicensed technologies like Wi-Fi. The licensed carrier provides the control plane and guaranteed QoS, while unlicensed carriers boost data throughput.
Purpose & Motivation
LAA was introduced to:
- Access additional spectrum in the 5 GHz unlicensed band - Increase network capacity without acquiring new licensed spectrum - Complement licensed LTE with opportunistic unlicensed capacity - Provide carrier-grade service with Wi-Fi coexistence
Key Features
- ✓Operation in 5 GHz unlicensed band
- ✓Listen Before Talk (LBT)
- ✓Licensed carrier as PCell anchor
- ✓Fair coexistence with Wi-Fi
- ✓Discovery Reference Signals (DRS)