UE Coexistence Control for LAA and WLAN in Unlicensed Bands
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Solution Overview
Problem
In-device coexistence (IDC) issues arise when a User Equipment (UE) operates both Long Term Evolution (LTE) and Wireless Fidelity (Wi-Fi) in an unlicensed band, leading to hardware conflicts and interference due to concurrent radio access technologies, necessitating improved management strategies.
Innovation Solution
The UE is configured to transmit capability information, receive IDC indications, detect interference, and send assistance information to resolve IDC issues through RRC messages, employing Time Domain Multiplexing (TDM) and Frequency Division Multiplexing (FDM) solutions, including autonomous denial of certain DL assignments or subframes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the UE supports both LAA SCell operation and WLAN/Wi-Fi operation in the unlicensed band, then the UE can provide flexible network connectivity options, but hardware conflict and interference occur due to shared RF circuitry
Solution Approach 1:
The patent segments the operation of LAA SCell and WLAN/Wi-Fi by separating them in the time domain through TDM gaps. The UE is configured with gap patterns that define dedicated time slots for each radio access technology, preventing simultaneous operation and associated hardware conflicts while maintaining both connectivity options.
Solution Approach 2:
The patent implements dynamic adjustment of TDM gap patterns and autonomous denial parameters based on real-time detection of IDC issues. The UE can adaptively modify gap configurations and denial ratios to resolve hardware conflicts dynamically, allowing flexible operation of both LAA and WLAN without fixed structural constraints.
2Ease of operation
If the UE performs WLAN background scanning to support user preferred network connectivity, then user connectivity preferences are met, but IDC interference occurs with LAA SCell operation
Solution Approach 1:
The patent applies preliminary action by configuring the UE with pre-defined TDM gap patterns and autonomous denial parameters before WLAN scanning occurs. When IDC issues are detected, the UE can immediately invoke these pre-configured parameters to resolve interference without requiring real-time network reconfiguration, thus maintaining ease of operation.
Solution Approach 2:
The patent enables self-service by allowing the UE to autonomously detect IDC issues and apply autonomous denial parameters to resolve conflicts without network intervention. The UE independently manages the balance between LAA operation and WLAN scanning, providing ease of operation while controlling harmful interference.
3Reliability
If the UE is configured with measurement on LAA frequencies, then LAA operation is optimized, but the UE cannot perform WLAN scanning without detach and attach procedure
Solution Approach 1:
The patent ensures continuity of useful action by maintaining LAA measurement configuration while enabling simultaneous WLAN scanning capability. The UE can continue optimized LAA operation through configured measurements while also performing background WLAN scanning without requiring detach and attach procedures, thus eliminating time loss.
Solution Approach 2:
The patent achieves universality by enabling the UE to simultaneously support both LAA operation with measurements and WLAN scanning functions. The UE becomes multi-functional, capable of optimizing LAA while also performing background connectivity discovery, eliminating the need to choose between the two functions.
4Object-generated harmful factors
If the UE uses autonomous denial framework to deny certain percentage of UL grants, then IDC issue is partially resolved, but DL assignments or subframes cannot be ignored
Solution Approach 1:
The patent extends the autonomous denial framework dynamically to include DL assignments and subframes, matching the flexibility already present for UL grants. The UE can adaptively deny both uplink and downlink transmissions based on real-time IDC conditions, achieving balanced control over bidirectional traffic while resolving interference.
Solution Approach 2:
The patent applies parameter changes by introducing new autonomous denial parameters specifically for DL assignments and subframes, extending the existing UL denial parameters. This allows the UE to adjust denial ratios and patterns for both directions of communication, providing comprehensive adaptability in controlling harmful interference.
Data Source
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AI summary
In an embodiment of the present invention, a method performed by a user equipment, UE, for resolving an in-device coexistence, IDC, problem is disclosed. The method comprises detecting an IDC problem between a licensed assisted access, LAA, operation and a wireless local area network, WLAN, operation on a secondary cell using an unlicensed band; in case that the IDC problem cannot be resolved by the UE, transmitting, to a base station, IDC assistance information including resource information associated with the IDC problem; and receiving, from the base station, a solution to resolve the IDC problem.