Wireless Device Rendezvous Algorithm for Unsynchronized Networks
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Solution Overview
Problem
Wireless devices with unsynchronized activation schedules in wireless communication networks face challenges in discovering and communicating with each other, as they must be awake and aligned in time to exchange information or use directional antennas, which is difficult and costly to coordinate.
Innovation Solution
A time-domain based rendezvous algorithm that determines active and inactive time units in each cycle, allowing devices to periodically awaken and communicate without pre-coordinated synchronization, using equations like Xi+1=(Xi+S)mod C to ensure overlapping active periods for communication and antenna alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If wireless devices use low duty cycles to extend battery life, then power consumption is reduced, but communication capability deteriorates because devices cannot communicate when inactive
Solution Approach 1:
The patent implements periodic activation where devices wake up at regular intervals according to a duty cycle schedule. Each device alternates between active and inactive states, with the active state occurring periodically. This allows devices to conserve energy during inactive periods while maintaining communication capability during active periods, resolving the contradiction between power consumption and communication reliability.
Solution Approach 2:
The patent uses pre-coordination mechanisms where devices exchange information about their activation schedules before entering inactive states. This preliminary action allows devices to know when to expect the other device to be active, enabling them to synchronize their communication attempts without needing to remain continuously active, thus maintaining communication capability while reducing power consumption.
2Length of moving object
If wireless devices use directional antennas to extend transmission range, then communication range is improved, but device complexity increases due to the need for synchronized antenna alignment
Solution Approach 1:
The patent implements a two-phase process: first, devices perform preliminary synchronization by exchanging beacon messages to align their activation schedules and antenna orientations. Once synchronized, devices can maintain their directional antenna orientations for extended periods, reducing the need for frequent realignment and thereby reducing device complexity while maintaining extended transmission range.
Solution Approach 2:
The patent uses periodic re-synchronization intervals where devices periodically update their antenna alignment and synchronization information. Between these periodic updates, devices maintain their directional orientations, which extends transmission range while minimizing the complexity of continuous synchronization by limiting realignment operations to periodic intervals.
3Reliability
If wireless devices require pre-coordinated synchronization to communicate, then communication reliability is improved, but ease of operation deteriorates due to the difficulty and cost of implementing coordination
Solution Approach 1:
The patent implements self-service synchronization where each device independently generates and follows its own activation schedule based on simple rules (such as duty cycle parameters and offset values). Devices autonomously determine when to wake up and communicate without requiring complex centralized coordination or negotiation protocols, thereby maintaining communication reliability while significantly simplifying the ease of operation.
Solution Approach 2:
The patent uses a universal synchronization mechanism based on duty cycle parameters that can be applied to any pair of devices regardless of their specific characteristics. This multi-functional approach allows the same simple coordination rules to work for all devices in the network, eliminating the need for device-specific coordination protocols and thereby improving ease of operation while maintaining communication reliability.
Data Source
AI summary
A method enables a wireless device (310) to rendezvous with another wireless device (320) through a wireless network (330), where activation schedules of the wireless devices are not synchronized. The method includes determining a number of time units in each cycle of multiple communication cycles, identifying active time units in each cycle during which the first wireless device enters an active mode, and identifying inactive time units in each cycle during which the first wireless device enters an inactive mode. The sum of the active time units and the inactive time units equals the number of time units in each cycle. A first active time unit in each cycle occupies a same position in the cycle as an active time unit in a previous consecutive cycle. Also, a second active time unit in each cycle occupies a different position in the cycle than any active time unit in the previous consecutive cycle.