Adaptive Handoff Hysteresis for Mobile Telecommunication Systems
Solution Overview
Problem
Current mobile telecommunication systems face challenges in accurately determining the proper time for handoff between base stations, leading to service interruptions and inefficiencies due to high failure rates in handoff mechanisms.
Innovation Solution
A method that involves measuring and predicting target and server power levels, calculating estimation and prediction errors, and determining a handoff hysteresis level to trigger a seamless transfer of a mobile station from a server station to a target station when the predicted target power exceeds the server power by a certain threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional handoff mechanisms are used to switch mobile stations between base stations, then service continuity is maintained, but handoff failure rate remains high causing service interruptions
Solution Approach 1:
The patent applies preliminary action by predicting future power levels of target and server base stations before the actual handoff occurs. The system calculates prediction errors and uses these to determine an adaptive hysteresis level in advance, allowing the handoff decision to be based on forecasted conditions rather than current measurements alone, thereby reducing handoff failures and service interruptions
Solution Approach 2:
The patent implements feedback by continuously monitoring actual power levels and comparing them against predicted values to calculate prediction errors. This error information feeds back into the system to dynamically adjust the hysteresis level for subsequent handoff decisions, creating a closed-loop control mechanism that improves handoff reliability over time
2Speed
If handoff decisions are made based on current power measurements, then response time is fast, but estimation errors lead to unnecessary handoffs and service failures
Solution Approach 1:
The system performs preliminary power level predictions for future time points before executing handoff decisions. By calculating prediction errors in advance and using these to determine an adaptive hysteresis threshold, the system maintains fast response capability while filtering out false handoff triggers caused by temporary power fluctuations or measurement errors
Solution Approach 2:
The patent changes the parameter used for handoff decisions from static current power measurements to dynamic adaptive hysteresis levels that incorporate prediction errors. This parameter transformation allows the system to distinguish between genuine signal degradation requiring handoff and temporary fluctuations that should be ignored, improving handoff accuracy without sacrificing response speed
3Device complexity
If fixed hysteresis level is used for handoff decisions, then system complexity is low, but it cannot adapt to varying channel conditions causing suboptimal handoff performance
Solution Approach 1:
The patent applies dynamics by transforming the static hysteresis level into a dynamic parameter that automatically adapts to varying channel conditions. The adaptive hysteresis level is continuously updated based on prediction errors derived from comparing actual and predicted power levels, allowing the system to respond to changing mobile station positions, interference patterns, and signal fading without manual intervention
Solution Approach 2:
The system performs self-service by automatically calculating prediction errors from its own power measurements and using these errors to adjust the hysteresis level for future handoff decisions. This self-adjusting mechanism eliminates the need for external configuration or manual tuning, allowing the handoff algorithm to adapt to specific channel conditions autonomously while maintaining relatively simple system architecture
Data Source
AI summary
A method of operation of a mobile telecommunication system includes: measuring a measured target power and a measured server power; predicting a future target power and a future server power for a prediction tap number from when the measured target power and the measured server power are measured; computing an estimation error and a prediction error associated with the future target power and the future server power; determining a handoff hysteresis level based on the estimation error and the prediction error; and sending a handoff trigger for transferring a mobile station from a server station to a target station when the future target power minus both the future server power and the handoff hysteresis level is greater than zero.