WLAN Traffic Offloading via Periodic Passive Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies in offloading traffic from cellular networks to wireless local area networks (WLANs), particularly due to high scan energy and latency in discovering WLAN access points, which affects power consumption and network congestion.
Innovation Solution
The proposed solution involves a method where a user equipment (UE) receives measurement configuration from a base station to enable efficient passive scanning for WLAN access points, using specific event-driven beacon transmission times and thresholds to trigger association or disassociation with WLANs, thereby optimizing power and spectral efficiency for traffic offloading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active scanning is used to discover WLAN access points, then the UE can find available WLAN networks, but the scan energy consumption and latency increase significantly
Solution Approach 1:
The patent implements periodic passive scanning where the UE monitors WLAN beacons at specific intervals rather than continuously scanning. The base station configures measurement objects with specific measurement timings, and the UE performs scans only at these periodic intervals, reducing energy consumption while maintaining reliable WLAN discovery.
Solution Approach 2:
The WLAN access points autonomously broadcast beacon signals containing network information, eliminating the need for the UE to actively query each potential access point. The UE simply needs to listen for these self-service beacons, significantly reducing the scanning energy and time required to discover WLAN networks.
2Speed
If continuous scanning is performed to maintain WLAN connectivity, then the UE can quickly detect network changes, but power consumption increases
Solution Approach 1:
The patent implements periodic scanning where the UE monitors WLAN beacons at specifically configured intervals rather than continuously. The base station provides measurement configurations with defined measurement timings, allowing the UE to balance between quick network change detection and power conservation by scanning only at necessary periodic moments.
Solution Approach 2:
The system uses feedback mechanisms where the UE reports measurement results to the base station, which then adjusts measurement configurations based on network conditions. This feedback loop allows the system to optimize scanning frequency dynamically, performing scans more frequently when network changes are likely and less frequently when conditions are stable, thus balancing speed and power consumption.
3Speed
If the UE autonomously decides when to associate with WLANs, then response time is reduced, but network optimization and load management deteriorate
Solution Approach 1:
The patent implements a feedback-based semi-autonomous association mechanism. The UE autonomously discovers WLAN networks through passive scanning and can quickly associate when conditions are favorable, maintaining fast response time. Simultaneously, the UE reports measurement results to the base station, which provides feedback on optimal association decisions based on network load and traffic conditions, thereby optimizing overall network performance and traffic offloading efficiency.
Solution Approach 2:
The base station pre-configures measurement objects and reporting criteria before the UE performs scanning. This preliminary configuration allows the UE to make informed autonomous association decisions based on pre-established criteria, reducing response time while ensuring that association decisions align with network optimization goals set by the base station.
4Use of energy by moving object
If passive scanning with event-driven beacons is used, then power consumption is reduced, but the complexity of managing measurement configurations increases
Solution Approach 1:
The base station's measurement configuration mechanism serves multiple functions: it defines scanning parameters, sets reporting thresholds, determines measurement timings, and optimizes power consumption all in a single unified configuration. This multi-functional approach consolidates complexity in the base station rather than the UE, simplifying the overall system while maintaining power efficiency through event-driven passive scanning.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Methods and apparatus for offloading traffic from a cellular network to a wireless local area network (WLAN) are described. One example method generally includes receiving, from a serving base station, a request to measure one or more WLAN access points (APs), determining one or more metrics for the WLAN APs, comparing the metrics for the WLAN APs to a threshold, and reporting metrics for at least a first AP of the WLAN APs if the metrics for the first AP exceed the threshold.