D2D Discovery Timing Coherence Relay User Equipment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Device-to-device communication in LTE networks faces challenges in maintaining coherent timing between user equipment, especially when one device is out of radio coverage, leading to unsuccessful discovery procedures.
Innovation Solution
A method where a relay user equipment, connected to a base station, transmits timing information and discovery signals with adjusted intervals to enable successful discovery between user equipment, even when one is out of network coverage, by applying extended reception intervals and synchronization indications based on estimated timer deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a user equipment operates out of radio coverage, then device-to-device communication autonomy is improved, but timing coherence with the network deteriorates
Solution Approach 1:
The network configures discovery time intervals and timing parameters in advance before the user equipment loses coverage. These pre-configured parameters enable the out-of-coverage device to maintain timing coherence without real-time network synchronization, allowing autonomous device-to-device communication while preserving timing relationships.
Solution Approach 2:
The patent uses pre-configured timing parameters as an intermediary between the network and out-of-coverage devices. These parameters act as a temporary timing reference that bridges the gap between network-synchronized operation and autonomous out-of-coverage operation, maintaining timing coherence without requiring continuous network connection.
2Reliability
If discovery time interval is extended to accommodate timer deviations, then discovery reliability is improved, but communication efficiency deteriorates
Solution Approach 1:
The patent dynamically adjusts the discovery time interval based on the estimated timer deviation. When timer drift is detected, the discovery interval is extended to accommodate the deviation and ensure reliable discovery. When timing coherence is maintained, the interval returns to normal, preserving communication efficiency. This adaptive parameter adjustment resolves the contradiction between reliability and efficiency.
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a method for improving or enabling radio coverage for a user equipment with respect to a mobile communication network, wherein the user equipment and a relay user equipment are enabled to use device to device communication mode (D2D mode), wherein the base station entity furthermore transmits an indication related to a discovery time interval, wherein in case that the relay user equipment is connected to the base station entity, and the user equipment – at a given point in time – has been connected to the base station entity or to another base station entity of the access network of the mobile communication network but is out of direct radio coverage with the base station entity at a further point in time, the method comprising at least either the first and second step or the third step: -- in the first step, the user equipment transmits a first discovery signal, the first discovery signal being received by the relay user equipment and the first discovery signal -- comprising a time limitation with respect to the discovery time interval, and/or -- comprising a synchronization indication, the synchronization indication being related to an estimated timer deviation of a timer within the user equipment with respect to the master timing schedule of the base station entity, -- in the second step, subsequent to the first step, the relay user equipment – upon reception of the first discovery signal from the user equipment – applies reception capabilities during a first reception time interval, the first reception time interval comprising but exceeding the discovery time interval in time, wherein the first reception time interval is dependent on the time limitation and/or the synchronization indication of the first discovery signal, -- in the third step the relay user equipment transmits a second discovery signal, the second discovery signal indicating the master timing schedule of the base station entity to the user equipment, and the user equipment applies reception capabilities during a second reception time interval, the second reception time interval comprising but exceeding the discovery time interval in time, wherein the second reception time interval is related to an estimated timer deviation of a timer within the user equipment with respect to the master timing schedule of the base station entity.