Cellular Load Sharing via Dynamic UE Grouping

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Solution Overview

Problem

Existing cellular communication systems face challenges in efficiently utilizing network and UE capabilities for effective load sharing between different base station nodes, leading to potential radio resource losses due to interference and varying UE interference suppression capabilities.

Innovation Solution

A method and device that define groups of radio devices based on capabilities and associate them with load sharing boundaries, gathering statistics on connection failures to dynamically adjust these boundaries, thereby optimizing load sharing and reducing interference-related issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If range expansion is applied by setting a cell selection offset parameter to expand the uptake area of low-power nodes, then load sharing between macro cell and micro/pico cells is improved, but downlink signal strength and link bitrate deteriorate due to UEs connecting to low power nodes

Engineering Contradiction:
Improveload sharingVSAvoiddownlink signal strength
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies different cell selection offset parameters to different UEs based on their individual interference suppression capabilities. UEs with good interference suppression capabilities receive a first cell selection offset parameter that enables range expansion to low-power nodes, while UEs with poor interference suppression capabilities receive a second, smaller offset parameter. This local differentiation allows load sharing to be improved for capable UEs without degrading downlink performance for incapable UEs.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the cell selection offset parameter based on UE capability and network conditions. The network node determines each UE's interference suppression capability and assigns appropriate offset values accordingly. This parameter adaptation enables the system to achieve load sharing benefits when conditions permit while avoiding performance degradation when conditions do not permit, thus resolving the contradiction between load sharing improvement and downlink signal strength maintenance.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If range expansion is applied by modifying the cell selection offset parameter for all UEs, then load sharing is improved, but interference from macro cell control signalling to UEs connected to micro/pico cell increases

Engineering Contradiction:
Improveload sharingVSAvoidinterference from macro cell control signalling
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent differentiates between UEs with good and poor interference suppression capabilities, applying different cell selection offset parameters to each group. This local quality approach ensures that only UEs capable of handling the additional interference from macro cell control signalling are subjected to aggressive range expansion, while other UEs receive more conservative offset values that protect them from harmful interference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces UE interference suppression capability as an intermediary criterion that mediates between the goal of load sharing and the harmful effect of macro cell interference. By using this intermediary property to guide parameter assignment, the system achieves load sharing only for UEs that can tolerate the associated interference, thus resolving the contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If range expansion is applied to balance load between different layers, then capacity of high-power nodes is saved for other terminals, but uplink performance in transition zones may be compromised due to path loss differences

Engineering Contradiction:
Improvenode capacity utilizationVSAvoiduplink performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent adjusts the cell selection offset parameter dynamically based on UE capability and measured signal conditions. For UEs with good interference suppression capabilities, larger offset values enable connection to low-power nodes even when downlink signal strength is lower, allowing capacity savings on high-power nodes. The system monitors uplink performance and can adjust parameters to maintain reliability while achieving load balancing.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3008939B1Load sharing in a cellular radio communication system
Publication Date: 2018.08.22 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3008939B1 patent drawingFigure 1~4
  • EP3008939B1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a method performed in a network node (10) of a cellular radio communication system (l) for facilitating load sharing between a serving cell (2) and a neighbouring cell (3) of the cellular radio communication system. The serving cell serves a plurality of radio devices (4). The method comprises defining a first group of radio devices, which first group is a subgroup of the plurality of radio devices served by the serving cell. The method also comprises associating the first group of radio devices with a load sharing boundary (5) to a load sharing zone (6) between the serving cell and the neighbouring cell, beyond which load sharing boundary any of the radio devices in the first group is regarded as being able to be handed over to the neighbouring cell. The method also comprises gathering statistics relating to connection failures experienced by the radio devices in the first group. The method also comprises adjusting the load sharing boundary based on the gathered statistics.