Vehicle WLAN Bandwidth Switching for DSRC Toll Interference
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Solution Overview
Problem
WLAN systems in automobiles experience interference from DSRC systems, particularly at toll booths, leading to complete jamming of Wi-Fi functions due to overlapping frequency bands, which affects in-car applications like Apple CarPlay and Android Auto.
Innovation Solution
WLAN devices in vehicles are configured to dynamically switch between bandwidths based on detected DSRC system locations, using a database of known positional information and clear channel assessment, employing action frames for channel switches to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If WLAN devices operate in 80 MHz bandwidth in U-NII-3 band, then throughput and data transmission speed are improved, but interference from DSRC systems completely jams the Wi-Fi function
Solution Approach 1:
The patent implements dynamic bandwidth switching between 80 MHz and 40 MHz modes based on real-time interference detection. The WLAN device monitors for DSRC system presence and automatically adjusts its operating bandwidth accordingly, transitioning from wide 80 MHz mode for high throughput to narrow 40 MHz mode to avoid interference, thus resolving the contradiction between productivity and interference avoidance
Solution Approach 2:
The system changes the operational parameter of bandwidth from fixed 80 MHz to dynamically selectable 80 MHz or 40 MHz based on interference conditions. By modifying this key parameter, the system maintains high throughput when interference is absent while avoiding complete jamming when DSRC systems are detected, balancing productivity and harmful factor mitigation
2Object-affected harmful factors
If WLAN devices switch to 40 MHz bandwidth to avoid DSRC interference, then interference is minimized, but throughput is reduced
Solution Approach 1:
The system dynamically adjusts bandwidth based on real-time detection of DSRC interference. When interference is absent, it operates at 80 MHz for maximum throughput; when interference is detected, it switches to 40 MHz to minimize harmful effects. This dynamic adaptation resolves the contradiction by making throughput sacrifice temporary and conditional rather than permanent
Solution Approach 2:
The WLAN device periodically monitors the radio environment for DSRC interference and switches bandwidth modes accordingly. This periodic assessment allows the system to maintain high throughput during most operating conditions while periodically sacrificing speed to avoid interference when necessary, balancing the two competing requirements
3Object-affected harmful factors
If the system continuously monitors for DSRC interference, then interference mitigation is improved, but device complexity increases
Solution Approach 1:
The WLAN device uses its own existing receive antenna and signal processing capabilities to detect DSRC interference, rather than requiring separate dedicated monitoring hardware. The system leverages its built-in radio frequency front-end and baseband processor to perform interference detection, thus improving detection accuracy without proportionally increasing device complexity
Solution Approach 2:
The same radio frequency receiver and signal processing chain used for normal Wi-Fi communication is also utilized for detecting DSRC interference. This multi-functional approach allows the system to perform both data transmission and interference monitoring using existing hardware, avoiding the need for additional dedicated monitoring components
Data Source
AI summary
Disclosed are methods and systems for a WLAN device to select an operating dynamic bandwidth selection (DBS) channel that minimizes the probability of interference from a dedicated short range communication (DSRC) device by using positional information. The WLAN device may operate on a first DBS channel of a plurality of DBS channels within a first bandwidth. The WLAN device may determine that the WLAN device is approaching a geo-tagged zone, where the geo-tagged zone interferes with operation of the WLAN device. The WLAN device may change the operation of the WLAN device from the first DBS channel to a second DBS channel within a second bandwidth in response to determining that the WLAN device is approaching the geo-tagged zone.