VRU Communication Sleep Modes for Low-Power V2X Safety

The patent implements discontinuous reception (DRX) cycles where the VRU device alternates between active monitoring periods and sleep periods. During active periods, the device monitors ITS messages at high frequency to ensure safety. During sleep periods, the device reduces power consumption by stopping monitoring. This periodic action resolves the contradiction by providing safety-critical continuous monitoring only when necessary, while allowing power-saving sleep modes during low-risk periods.

The patent dynamically adjusts the monitoring frequency and DRX cycle parameters based on contextual factors such as location, traffic density, and risk level. When the VRU device detects high-risk conditions (e.g., approaching intersections, high vehicle density), it increases monitoring frequency. In low-risk conditions, it reduces frequency to save power. This dynamic adaptation resolves the contradiction by matching power consumption to actual safety requirements.

The patent employs feedback mechanisms where the VRU device continuously assesses the current risk level based on environmental sensors, location data, and received ITS messages. This feedback informs real-time adjustments to DRX cycle parameters. When risk increases, the device wakes up more frequently; when risk decreases, it extends sleep periods. This feedback loop ensures monitoring continuity is maintained precisely when needed while maximizing power savings during safe periods.

The patent performs preliminary risk assessment and predicts potential hazard zones in advance. Before entering high-risk areas (e.g., intersections, pedestrian zones), the device proactively adjusts its DRX cycle to increase monitoring frequency. This preliminary action ensures that monitoring continuity is already established before safety-critical events occur, resolving the contradiction by preparing the system in advance rather than reacting after power savings compromise monitoring.

The patent applies location-based communication by activating ITS message transmission and reception only in specific geographic zones where VRUs are at risk (e.g., near intersections, pedestrian crossings, highway entrances). Outside these zones, the device remains in low-power mode. This local quality approach resolves the contradiction by concentrating communication resources only where energy waste from unnecessary transmission would occur, while avoiding the need for complex protocols everywhere.

The patent implements contextual activation where the VRU device autonomously determines when to activate or deactivate ITS communication based on its own contextual information (location, movement state, environmental sensors). The device self-manages its communication activity without requiring complex external coordination or sophisticated protocol negotiations with the network. This self-service approach reduces energy waste from unnecessary communication while keeping device complexity manageable by using simple, rule-based contextual evaluation.