WLAN AP Scanning via Base Station Load Feedback
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Solution Overview
Problem
Existing methods for a User Equipment (UE) to discover Wireless Local Area Network (WLAN) Access Points (APs) are inefficient, leading to increased power consumption and poor performance due to the inability to accurately select APs with light loads, resulting in overloaded networks and decreased throughput.
Innovation Solution
A method where the UE uses a specific AP scanning channel set by a Base Station (BS) or AP management entity to actively scan for WLAN APs, with APs transmitting probe response frames after offset times based on their load states, allowing the UE to select APs with the lightest loads and reducing scanning time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the UE performs active scanning by transmitting probe request frames to discover WLAN APs, then the AP discovery time per channel is reduced compared to passive scanning, but the terminal generates additional packets which act as a burden to the terminal and increase power consumption
Solution Approach 1:
The BS pre-collects information on WLAN APs including their channels and load states before the UE performs scanning. This preliminary preparation allows the UE to efficiently scan only necessary channels and select appropriate APs without excessive power consumption from scanning all channels or dealing with overloaded APs.
Solution Approach 2:
The BS provides feedback to the UE about the load states of various WLAN APs through collected information. This feedback mechanism enables the UE to make informed decisions about which APs to scan and connect to, avoiding wasted power on scanning that would lead to connection rejection due to overload.
2Reliability
If the UE scans for WLAN APs without knowing the network load, then the UE can discover available APs, but the UE cannot guarantee good performance and may access overloaded APs resulting in throughput degradation
Solution Approach 1:
The BS pre-collects load state information from WLAN APs before the UE performs scanning. This advance collection of information ensures that when the UE discovers APs, it has access to current load data, enabling reliable selection of underloaded APs and guaranteeing better service performance.
Solution Approach 2:
The BS acts as an intermediary between WLAN APs and the UE. It collects load information from APs and provides this information to the UE, eliminating the need for the UE to directly query APs for load information and ensuring accurate, up-to-date load data is available for decision-making.
3Productivity
If multiple UEs access the same overloaded WLAN AP, then the AP can serve more users, but the throughput of each UE rapidly decreases and the AP overload ratio increases
Solution Approach 1:
The system segments the UE population based on AP load information. The BS collects load states from different APs and provides this segmented information to UEs, allowing UEs to select APs based on current load conditions. This segmentation prevents concentration of UEs on overloaded APs and distributes them across multiple APs appropriately.
Solution Approach 2:
The system dynamically adjusts UE AP selection based on real-time load information. The BS continuously collects load states from WLAN APs and updates the information provided to UEs, enabling dynamic load balancing where UEs can switch between APs as load conditions change, maintaining optimal throughput for all users.
4Loss of information
If the UE receives and decodes beacon or probe response frames to identify AP load, then the UE can know AP load before accessing, but the basic limitation of not reducing WLAN AP discovery time still exists
Solution Approach 1:
The invention extracts the load information collection function from the UE and relocates it to the BS. The BS collects load information from WLAN APs independently, and the UE simply receives this pre-collected information from the BS. This extraction eliminates the time-consuming process of UE receiving and decoding beacon or probe response frames while still providing complete load information.
Solution Approach 2:
The BS creates a copy of the load information from WLAN APs and provides this copied information to the UE. Instead of the UE directly interacting with APs to obtain load information through time-consuming beacon or probe response frame exchanges, the BS copies the necessary information and delivers it efficiently to the UE.
Data Source
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AI summary
The present invention relates to a method and an apparatus enabling a terminal to obtain information required for a wireless LAN AP search from a cellular base station in order to use a wireless LAN service, and to access a wireless LAN AP having a low network load in a short time. The communication method of a terminal according to one embodiment of the present invention may comprise the steps of: switching a channel to an AP scanning channel, which is a channel for searching for a wireless LAN AP between the terminal and the wireless LAN AP; transmitting a wireless LAN AP search signal from the AP scanning channel; receiving, from the wireless LAN AP, a wireless LAN AP response signal, transmitted after an offset time set in accordance with the load state of the wireless LAN AP; and switching the channel to a data transmitting and receiving channel for data communications with the wireless LAN AP. According to one embodiment of the present invention, the terminal can always select the AP having the lowest load by performing a search on all surrounding wireless LAN APs.