WLAN Access Point RF Power Redistribution for Load Balancing
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Solution Overview
Problem
Wireless local area networks (WLANs) face challenges in maintaining quality of service (QoS) due to excessive loading on access points (APs), which can lead to compromised data throughput and service quality for clients, especially when legacy terminals are involved, as existing methods often require changes to mobile devices or compromise QoS by reducing data rates or bandwidth.
Innovation Solution
The method involves monitoring QoS requirements across WLANs, identifying when an AP is nearing maximum capacity, and adjusting the RF transmission power of neighboring APs to redistribute client load by increasing the RF coverage area of adjacent APs and decreasing the overloaded AP's coverage area, allowing for seamless handovers and maintaining uncompromised QoS without requiring modifications to legacy mobile devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the AP increases data rates and bandwidth to serve more clients, then the productivity of the network is improved, but the QoS for individual clients deteriorates when the AP reaches capacity
Solution Approach 1:
The patent segments the network load by redistributing clients from the overloaded AP to neighboring APs. This is achieved by dynamically adjusting RF transmission power levels to create varying RF coverage areas, effectively dividing the client population across multiple access points to prevent any single AP from reaching capacity while maintaining high throughput for all clients.
Solution Approach 2:
The patent implements dynamic adjustment of RF transmission power levels based on real-time load conditions. The system continuously monitors AP capacity and dynamically modifies the RF coverage area of overloaded APs and their neighbors, allowing the network to adapt to changing traffic patterns and maintain optimal QoS without sacrificing productivity.
2Reliability
If the AP reduces data rates or bandwidth to maintain service quality, then the QoS for clients is improved, but the data throughput and network productivity deteriorate
Solution Approach 1:
The patent extracts clients from the overloaded AP by redistributing them to neighboring APs with available capacity. This is accomplished by adjusting RF power levels to make neighboring APs more attractive for client association, thereby removing excess load from the congested AP without reducing data rates or bandwidth for remaining clients, thus preserving both QoS and throughput.
Solution Approach 2:
The patent introduces neighboring APs as intermediary nodes to handle the overflow of clients from the overloaded AP. By dynamically adjusting RF coverage, the system uses neighboring APs as mediators to absorb excess traffic, allowing the overloaded AP to maintain high data rates for its remaining clients while still providing service to all clients through the network.
3Reliability
If the AP increases RF transmission power to expand coverage area, then the network availability is improved, but the loading on the AP increases causing QoS deterioration
Solution Approach 1:
The patent applies local quality by differentiating RF transmission power levels across different APs based on their specific load conditions and geographic locations. Overloaded APs reduce their RF power to decrease coverage area and attract fewer clients, while neighboring APs increase their RF power to expand coverage and accept relocated clients, creating a non-uniform but optimal distribution of network resources.
Solution Approach 2:
Instead of increasing RF power to handle more clients (the conventional approach), the patent inverts the strategy by reducing RF power on overloaded APs to deliberately decrease their coverage area and attract fewer clients. This counterintuitive approach redistributes load to neighboring APs, preventing capacity exhaustion while maintaining network availability.
4Productivity
If the AP decreases RF coverage area to reduce loading, then the AP capacity is improved, but the network availability in certain areas deteriorates
Solution Approach 1:
The patent merges the functionality of multiple APs by dynamically adjusting their RF coverage areas. When an AP reduces its power and coverage, neighboring APs expand theirs, creating a collaborative network where multiple APs work together to maintain coverage. This merging of coverage functions across multiple nodes ensures that reducing load on one AP does not compromise overall network availability.
Data Source
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AI summary
Methods and apparatus for use in controlling the loading of wireless access points (APs) in a wireless local area network (WLAN) in support of legacy terminals are disclosed. The WLAN has at least a first AP and a second wireless AP adjacent the first wireless AP. An indication which indicates whether a loading of the second wireless AP is greater than a predetermined threshold is identified. When the indication indicates that the loading is greater than the predetermined threshold, a first nominal radio frequency (RF) transmission power of the first wireless AP is increased in order to increase a first RF coverage area of the first wireless AP. A second nominal RF transmission power of the second wireless AP is correspondingly reduced in order to reduce a second RF coverage area of the second wireless AP. In response, some of the mobile communication devices initially operating with the second wireless AP are switched to operate with the first wireless AP in order to reduce the loading of the second wireless AP. The techniques may be embodied in a centralized approach where transmission control equipment of the WLAN controls each wireless APs in this manner, or alternatively in a distributed non-centralized approach where each wireless AP acts independently and autonomously in the same or similar manner. Preferably, the techniques do not require the functional requirements of mobile devices to modified and therefore are suitable for use with existing legacy devices.