Ephemeris Data Validity Extension for GNSS Server Traffic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The peak server traffic loads in Global Navigation Satellite Systems (GNSS) experience significant congestion when delivering assistance data to a large number of client devices, particularly around the expiry times of Ephemeris data, leading to cyclical peak traffic conditions that increase costs and operational challenges.
Innovation Solution
The method involves modifying the Ephemeris data's validity period by adjusting the Time of Ephemeris (TOE) parameter and other parameters, allowing the data to be extended by up to 30 minutes, thereby spreading out the timing of assistance requests and reducing peak traffic loads at the server.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the server delivers Ephemeris assistance data to a large number of client devices with standard validity periods, then the GNSS receivers can maintain positioning accuracy, but the server experiences peak traffic loads and congestion around Ephemeris expiry times
Solution Approach 1:
The patent applies periodic action by extending the Ephemeris validity period from the standard 4-6 hours to up to 24 hours or more, creating a longer cycle between server requests. This reduces the frequency of peak traffic occurrences while maintaining positioning accuracy through the extended validity period, directly resolving the contradiction between reliability and server productivity
Solution Approach 2:
The patent implements preliminary action by pre-calculating and providing extended validity Ephemeris data that covers future time periods beyond the standard expiry time. This allows client devices to operate without needing to request updated Ephemeris data during the extended period, preventing peak traffic loads before they occur and maintaining continuous positioning accuracy
2Reliability
If the server increases capacity to handle peak traffic loads, then congestion issues are mitigated, but system costs increase due to excess capacity between cycles
Solution Approach 1:
By extending the Ephemeris validity period to create longer operational cycles, the patent reduces the frequency of peak traffic events. This allows servers to operate at lower average capacity levels while still meeting peak demands, eliminating the need for expensive excess capacity and directly reducing system costs while maintaining adequate server capacity
Solution Approach 2:
The patent applies partial action by providing extended validity Ephemeris data only when it serves to reduce peak loads, rather than always using maximum server capacity. This optimized approach maintains necessary server capacity during actual peaks while avoiding the cost of permanently over-provisioned systems
3Productivity
If the Ephemeris validity period is extended, then peak traffic loads are reduced, but the accuracy of satellite position may degrade beyond the model fit period
Solution Approach 1:
The patent applies parameter changes by modifying the Time of Ephemeris (TOE) parameter and other orbital elements to extend the validity period. By carefully adjusting these parameters within acceptable degradation thresholds, the system maintains sufficient satellite position accuracy for extended periods while achieving the goal of reduced peak traffic loads through longer validity cycles
Data Source
AI summary
A system and method for reducing peak loads on a network, includes: a server in communication with a plurality of GPS receivers, the receivers sending requests for an ephemeris to the server when a time of ephemeris (TOE) for a previous ephemeris expires; and the ephemeris received by the receivers being adjusted by the addition of a value to the TOE of the ephemeris, the value being randomly adjusted to a 16 second interval between 16 seconds and 30 minutes.