Small Cell Base Station Power Saving via Stepped Reference Signal Reduction

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Solution Overview

Problem

Existing methods for controlling the operation mode of small cell base stations in heterogeneous networks do not achieve sufficient power saving, as they passively rely on the presence of terminals, leading to inefficient power consumption when the load of macro cells is low.

Innovation Solution

A communication control apparatus and method that transition the operation mode of small cell base stations from an active mode to a power-saving mode by stepwisely reducing transmission power and allowing time for terminals to switch connections, with the reduction in power set dynamically based on the number of connected terminals and communication quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If the operation mode of a small cell base station is passively controlled depending on presence of a terminal in the vicinity, then the small cell can be activated when needed, but sufficient power saving is not achieved when macro cell load is low and few terminals exist

Engineering Contradiction:
Improvepower consumption of small cell base stationVSAvoidsystem efficiency
Core Design Contradiction:
Use of energy by stationary objectVSProductivity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting transmission power levels of reference signals in a stepped manner (e.g., from 23 dBm to 20 dBm to 17 dBm) before transitioning to power-saving mode. This gradual parameter adjustment allows terminals to detect and switch to alternative base stations while the small cell remains technically operational, achieving both power savings and maintained system efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by reducing transmission power of reference signals before actually switching to power-saving mode. This preliminary power reduction serves as a warning signal to terminals, giving them time to switch connections to other base stations (macro cells or other small cells) before the small cell fully transitions to low-power state, thus avoiding service disruption.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by stationary object

If transmission power is reduced to enable power-saving mode transition, then power consumption decreases, but terminals may experience connection disruption

Engineering Contradiction:
Improvepower consumptionVSAvoidconnection stability
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by implementing a multi-step transmission power reduction process with intermediate waiting periods. Instead of abruptly cutting power, the system gradually reduces reference signal power (e.g., 23→20→17 dBm) and waits for terminals to complete handover at each step, cushioning the transition to prevent connection disruption while achieving power savings.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent implements periodic action through the stepped power reduction process with periodic waiting intervals. The transmission power is reduced in discrete steps with periodic pauses to allow terminal response and connection switching, creating a rhythmic transition pattern that maintains reliability while reducing power consumption.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3035726B1Communication control apparatus, communication control method and radio communication system
Publication Date: 2019.08.07 SONY GROUP CORP
  • EP3035726B1 patent drawingFigure 1A
  • EP3035726B1 patent drawingFigure 1B
  • EP3035726B1 patent drawingFigure 1C

AI summary

[Object] To enable further power saving in a heterogeneous network. [Solution] Provided is a communication control apparatus including: a radio communication unit configured to provide second radio communication service within a cell in which a first base station provides first radio communication service; and a control unit configured to, when an operation mode of the radio communication unit is made to transition from a first mode to a second mode in which power is less consumed than in the first mode, switch the operation mode to the second mode after stepwisely reducing transmission power of a reference signal to be transmitted from the radio communication unit.