D2D Frequency Selection for LTE Traffic Offloading

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Solution Overview

Problem

Current LTE systems require network traffic to be routed through base stations for direct communication between user equipment (UEs), leading to increased network loading, even when UEs are in close proximity, as peer-to-peer communication is not yet feasible.

Innovation Solution

A method that involves user equipment performing full or partial band searches to select a suitable frequency for device-to-device (D2D) communication, using a database of available operators and frequencies, allowing direct communication without base station intervention, either using a public frequency or an operator-assigned frequency based on band capacity and search results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UEs communicate through base station in LTE system, then communication reliability is ensured, but network loading increases and communication efficiency decreases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidcommunication efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the communication function from the base station infrastructure and implements it directly between UEs through D2D communication. By taking out the mandatory base station routing requirement and allowing direct UE-UE communication, the system achieves both reliability (through direct link) and improved efficiency (by bypassing base station for local communications).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces frequency selection as an intermediary mechanism to enable D2D communication. The frequency selection process (full band search, partial band search, D2D frequency determination) acts as a mediator that facilitates direct UE communication while ensuring proper resource allocation and interference management, thus improving efficiency without compromising reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Extent of automation

If base station forwards all data between UEs, then network control is maintained, but network loading increases

Engineering Contradiction:
Improvenetwork controlVSAvoidnetwork loading
Core Design Contradiction:
Extent of automationVSQuantity of substance

Solution Approach 1:

The patent segments network traffic into two categories: traffic requiring base station control (non-D2D traffic) and traffic that can be handled directly by UEs (D2D traffic). By segmenting the communication paths, the system maintains network control over necessary traffic while offloading local traffic directly between UEs, thereby reducing overall network loading on base stations.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If D2D communication is implemented without frequency selection, then device complexity is reduced, but interference management becomes problematic

Engineering Contradiction:
Improvecommunication protocol complexityVSAvoidradio frequency interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing frequency selection (full band search and partial band search) before establishing D2D communication. This preliminary frequency determination ensures that UEs select appropriate frequencies in advance, avoiding interference issues during actual communication while keeping the D2D protocol itself relatively simple.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3030037B1Method of offloading network traffic to a device-to-device communication and related wireless network system
Publication Date: 2019.05.22 ACER INC
  • EP3030037B1 patent drawingFigure 1
  • EP3030037B1 patent drawingFigure 2A
  • EP3030037B1 patent drawingFigure 2B

AI summary

In a wireless communication system, a first UE may conduct a D2D communication with a second UE using a frequency selected according to the band capacity of the first and second UEs and the result of the band searches performed by the first and second UEs. The first UE may also conduct the D2D communication with the second UE using a frequency assigned by a network or using a public frequency. Therefore, network traffic can be offloaded to the D2D communication with an increased D2D communication bandwidth.