Dynamic Relay Backhaul Timer Adjustment for UE Load

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Solution Overview

Problem

In cellular wireless networks, relay nodes (RNs) face challenges in maintaining seamless coverage due to communication errors on the relay backhaul air interface, which can lead to reduced quality of service for UEs, especially when a high number of UEs are being served, as existing timer durations are fixed and do not adapt to the number of served UEs.

Innovation Solution

The RN dynamically adjusts the timer durations (T310 and T311) based on the number of UEs being served, decreasing the timer duration as the number of UEs increases, to quickly resolve communication errors and minimize service disruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If fixed timer durations are used for relay backhaul link failures, then the system is simple to operate, but service disruption duration increases when many UEs are served

Engineering Contradiction:

Improvetimer configuration simplicityVSAvoidservice disruption duration

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The timer duration is made dynamic by adjusting it based on the number of UEs served by the relay node. The base station determines the appropriate timer duration according to the UE count and configures it to the relay node, allowing the system to adapt between fixed simplicity and dynamic optimization based on operational conditions

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The timer duration parameter is changed based on the number of served UEs. When the UE count exceeds a threshold, a shorter timer duration is configured to enable faster failure detection and recovery, reducing service disruption time for high-traffic relay nodes

Inventive Principle:

Principle #35Parameter changes

2Reliability

If longer timer durations are used, then false failures are avoided, but service disruption duration increases

Engineering Contradiction:

Improvefalse failure avoidanceVSAvoidservice disruption duration

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

Different timer durations are applied to different relay nodes based on their local conditions, specifically the number of UEs they serve. Relay nodes with more UEs receive shorter timer durations optimized for their high-traffic status, while those with fewer UEs use longer durations to avoid false failures

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The timer duration is dynamically adjusted based on the operational load (number of served UEs) of each relay node, allowing the system to optimize between reliability and recovery speed for each individual node based on its current state

Inventive Principle:

Principle #15Dynamics

3Loss of time

If shorter timer durations are used, then service disruption is minimized, but false failures increase

Engineering Contradiction:

Improveservice disruption durationVSAvoidfalse failure rate

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The timer duration parameter is changed based on the number of served UEs, with shorter durations assigned to relay nodes handling more UEs to minimize service disruption, while longer durations are assigned to low-traffic nodes to prevent false failures

Inventive Principle:

Principle #35Parameter changes

4Device complexity

If fixed timer durations are used, then device complexity is low, but quality of service deteriorates when many UEs are served

Engineering Contradiction:

Improvetimer management complexityVSAvoidquality of service

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The base station receives feedback information about the number of UEs served by each relay node and uses this feedback to determine and configure appropriate timer durations, creating a closed-loop system that optimizes quality of service based on actual operational conditions

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The timer management system transitions from a static fixed-duration approach to a dynamic condition-based approach, where timer durations are adjusted according to the number of served UEs, improving quality of service without significantly increasing overall system complexity

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10085161B1Dynamic variation of radio link failure timer duration for relay backhaul link, with timer duration being set based on number of served UEs

Publication Date: 2018.09.25 SPRINT SPECTRUM LLC

AI summary

Disclosed are methods and systems to facilitate variation of timer duration. In particular, a relay node (RN) may be configured to be served by a base station (BS) over a relay backhaul air interface and may be configured to serve user equipment devices (UEs) over a relay coverage air interface. Also, the RN may be configured (i) to detect when a threshold error in communication occurs on the relay backhaul air interface, (ii) in response to detecting the threshold error in communication, to start a timer that runs for a timer duration, and (iii) to respond to expiration of the timer duration by engaging in management of the relay backhaul air interface. With these arrangements, the RN may determine a count of how many UEs are being served by the RN over the relay coverage air interface and may set the timer duration based on the determined count of UEs.