Autonomous Uplink Channel Access in Heterogeneous Cellular Networks
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Solution Overview
Problem
Femto cells deployed in heterogeneous networks face challenges in determining suitable carrier selection and transmission power to avoid interference with victim eNBs, especially when far away, and in optimizing channel access without relying on downlink signaling.
Innovation Solution
Local devices measure interference levels on uplink resources, calculate a probability of channel access based on highest and lowest interference values, and transmit these values to a femto node for collective decision-making, allowing autonomous carrier reselection and power setting to minimize interference and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If local devices transmit at higher power to improve communication quality, then transmission reliability is improved, but interference to victim eNB increases
Solution Approach 1:
The patent implements dynamic transmission power adjustment where local devices continuously monitor interference levels on uplink resources and adapt their transmission power accordingly. The power level is dynamically changed based on real-time channel conditions and interference measurements, allowing the system to optimize between reliability and interference mitigation.
Solution Approach 2:
The patent changes the transmission power parameter based on measured interference values. By calculating probability of access based on interference levels and adjusting power accordingly, the system modifies the power parameter to balance communication quality and interference reduction to victim eNB.
2Extent of automation
If local devices autonomously select carriers without downlink signaling to reduce network assistance, then system autonomy is improved, but ability to determine suitable carrier decreases
Solution Approach 1:
The patent enables local devices to autonomously perform carrier selection and power adjustment without relying on downlink signaling from the network. Devices self-monitor interference levels, self-calculate access probabilities, and self-adjust transmission parameters, achieving complete operational autonomy in the uplink.
Solution Approach 2:
The patent implements a feedback mechanism where local devices measure interference levels on uplink resources, use these measurements to calculate probability of access, and adjust their carrier selection and power settings based on this feedback. This closed-loop feedback enables autonomous operation while maintaining accurate carrier determination.
3Object-generated harmful factors
If local devices deploy far from victim eNB to reduce interference, then interference to victim eNB is reduced, but channel selection capability decreases
Solution Approach 1:
The patent performs preliminary interference measurements on multiple uplink resources before making channel selection decisions. By proactively measuring interference levels across different carriers and resources, local devices can identify suitable channels in advance, maintaining channel selection capability even when deployed at various distances from victim eNB.
Solution Approach 2:
The patent enables dynamic carrier selection where local devices can switch between different uplink carriers based on real-time interference measurements. This dynamic adaptability allows devices to maintain channel selection capability regardless of their deployment location relative to the victim eNB.
Data Source
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AI summary
Methods, apparatuses, and software can be provided for dynamic autonomous resource allocation and channel access in a cellular system uplink. A method can include measuring interference levels on uplink resources of a victim cell and calculating a probability of accessing channels of the uplink resources of the victim cell using the measured interference levels, including defining a suitable transmission power, and a highest value and a lowest value. The method can further include accessing a channel for which the probability of accessing has been calculated, when the probability meets a predetermined condition.