LTE-A Unlicensed Spectrum Allocation via WLAN Beacon Scanning
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Solution Overview
Problem
Current technologies face challenges in deploying UMTS LTE-A in unlicensed frequency bands used by WLAN, leading to performance degradation for both systems due to interference and inefficiencies in channel allocation.
Innovation Solution
The method involves determining communication activity rates and scanning for WLAN beacon signals to select and allocate WLAN channels for UMTS LTE-A communication, prioritizing secondary channels over primary ones and un-used channels with lower traffic loads, to minimize impact on WLAN performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If UMTS LTE-A uses unlicensed frequency bands for communication, then spectrum utilization is improved, but WLAN performance deteriorates due to interference
Solution Approach 1:
The patent segments the unlicensed spectrum into primary channels and secondary channels. LTE-A is allocated secondary channels while WLAN uses primary channels, allowing both systems to coexist with reduced interference. This segmentation enables spectrum sharing by dividing the frequency band into distinct allocation zones for different radio access technologies.
Solution Approach 2:
The patent applies local quality by assigning different channel types (primary vs secondary) to different WLAN access points based on their specific deployment scenarios. Each access point can be configured with appropriate primary and secondary channels according to local interference conditions and traffic requirements, optimizing coexistence performance in each local environment.
2Ease of operation
If LTE-A allocates channels without considering WLAN activity, then channel allocation simplicity is improved, but interference with WLAN increases
Solution Approach 1:
The patent implements feedback mechanisms where LTE-A network nodes monitor WLAN communication activity on primary channels and adjust secondary channel allocation accordingly. When WLAN activity is detected on primary channels, the system provides feedback to modify LTE-A transmissions on secondary channels, reducing interference while maintaining efficient spectrum utilization.
Solution Approach 2:
The patent applies preliminary action by pre-allocating secondary channels for LTE-A use before WLAN interference occurs. The system proactively identifies suitable secondary channels and configures LTE-A access points to use them, preventing interference before it happens rather than reacting to interference after it occurs.
3Reliability
If WLAN uses CSMA/CA for channel access, then collision avoidance is improved, but throughput decreases due to time-sharing
Solution Approach 1:
The patent segments channel access mechanisms by assigning CSMA/CA to primary channels for WLAN while enabling more efficient access methods on secondary channels for LTE-A. This segmentation allows WLAN to maintain collision avoidance on primary channels while LTE-A achieves higher throughput on secondary channels, reducing the overall impact of time-sharing limitations.
Data Source
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AI summary
A method of a network node is disclosed. The network node is adapted to operate in accordance with a first radio access technology for allocation of radio resources of a frequency band (e.g. an unlicensed frequency band) to communication in accordance with the first radio access technology, wherein communication according to a second radio access technology may occupy one or more of the radio resources of the frequency band. The method comprises receiving a beacon signal associated with the second radio access technology and determining whether or not the beacon signal comprises information indicative of which of the radio resources of the frequency band are used as primary and secondary channels, respectively, in accordance with the second radio access technology. The method also comprises determining a communication activity rate of at least one of the radio resources of the frequency band. The method also comprises selecting one or more of the radio resources of the frequency band based on the determined communication activity rate (wherein, if the beacon signal comprises information indicative of which of the radio resources of the frequency band are used as primary and secondary channels, the selection is further based on the information), and allocating one or more of the selected radio resources to communication in accordance with the first radio access technology. Corresponding scheduler, network node and computer program product are also disclosed.