Base Station Beamforming for Unlicensed Band Access
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Solution Overview
Problem
Mobile telephony operators face challenges in accessing unlicensed frequency bands due to high demand and interference from overlapping base station coverage, which affects communication quality and accessibility.
Innovation Solution
A method that allows base stations to switch from omnidirectional to directional transmission mode using beamforming, enabling user devices to access a shared frequency band with reduced interference by broadcasting requests and confirmation messages in dedicated time windows, thereby improving access and communication quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mobile terminals use unlicensed frequency bands to increase throughput, then network capacity is improved, but accessibility is reduced and communication quality deteriorates due to interference from overlapping base station coverage
Solution Approach 1:
The patent segments the frequency band usage by introducing dedicated time windows for different transmission types. During first time windows, base stations perform mode change requests and confirmations using directional transmission. During second time windows, user devices access unlicensed frequency bands. This temporal segmentation reduces interference between base station communications and user device unlicensed band access, allowing both to coexist with improved communication quality.
Solution Approach 2:
The patent implements periodic time windows that alternate between base station mode change operations and user device unlicensed band access. This periodic structure allows systematic coordination between licensed and unlicensed band usage, ensuring that base stations and user devices do not simultaneously transmit in a way that causes interference, thereby maintaining communication quality while enabling unlicensed band utilization.
2Productivity
If multiple mobile terminals use unlicensed frequency bands simultaneously, then network capacity increases, but access difficulty increases due to high demand and lack of coordination
Solution Approach 1:
The patent employs preliminary action by having base stations broadcast mode change requests to user devices before user devices attempt to access unlicensed frequency bands. User devices receive and process these requests in advance, coordinating their unlicensed band access with base station transmissions. This preliminary coordination reduces access conflicts and makes frequency band acquisition easier for multiple terminals.
Solution Approach 2:
The patent implements feedback mechanisms where base stations send mode change requests to user devices, and user devices provide confirmations back to base stations. This feedback loop allows base stations to understand which user devices are capable of and willing to use unlicensed frequency bands, enabling better resource allocation and coordinated access that improves ease of operation for multiple terminals.
3Area of stationary object
If base stations use omnidirectional transmission mode, then coverage area is maximized, but interference to user devices accessing unlicensed frequency bands increases
Solution Approach 1:
The patent makes the transmission mode dynamic by allowing base stations to switch between omnidirectional and directional transmission modes based on operational requirements. During mode change time windows, base stations use directional transmission to reduce interference. During normal operation, they can use omnidirectional mode for maximum coverage. This dynamic adaptation resolves the contradiction between coverage area and interference level.
Solution Approach 2:
The patent applies local quality by using directional transmission in specific spatial directions during mode change operations. Instead of uniformly transmitting in all directions, base stations concentrate energy in specific directions, reducing interference in other directions where user devices are accessing unlicensed frequency bands. This localized transmission quality control maintains coverage while reducing harmful interference.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the probability of accessing unlicensed frequency bands and reduces interference, making it easier for user devices to use shared frequency bands while maintaining connectivity within their primary base station coverage.
Implementation Method 1
A method that allows base stations to switch from omnidirectional to directional transmission mode using beamforming
Data Source
AI summary
Mobile telephony operators are starting to use unlicensed frequency bands in order to increase the throughput of their mobile telephony network at a low cost. However, the use of the unlicensed frequency bands has certain drawbacks. It is difficult for a mobile terminal to use unlicensed frequency bands as the number of mobile terminals wishing to use these unlicensed frequency bands remains high given the capacities of these frequency bands. The development allows a user device located in a zone of overlapping radio coverage of two base stations to use a shared frequency band with a greater probability of access to the frequency band, while reducing the impact of interferences generated by communications established between user devices and the base stations to which they are connected.