FDD-TDD Band Switching for Broadcast Service Access

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Solution Overview

Problem

UMTS mobile network operators face challenges in offering new services like MBMS without disrupting existing services due to saturation of FDD frequency bands, which are also shared among multiple operators, making it difficult to provide broadcasting services that require significant radio resources.

Innovation Solution

A device and method for user terminals to analyze signaling information and switch between FDD and TDD frequency bands, allowing data frames from an FDD radio access network to be received on TDD frequency blocks, enabling efficient use of available frequency bands without requiring dual transceivers or separate networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If FDD frequency bands are used for existing services, then service coverage is maintained, but new broadcasting services cannot be offered due to saturation

Engineering Contradiction:
Improveservice offering capabilityVSAvoidavailable radio resources
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent extends the frequency domain dimension by enabling user terminals to access services on TDD frequency bands in addition to FDD bands. This dimensional expansion allows broadcasting services to be offered without consuming additional FDD radio resources, thereby resolving the contradiction between service versatility and resource availability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If FDD bands are shared among multiple operators, then spectrum utilization is efficient, but broadcasting services require significant resources that disrupt other services

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidservice disruption risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the radio access network services by frequency band type, allowing different services to operate on different bands. Broadcasting services are directed to TDD bands while existing services continue on FDD bands, eliminating service disruption risks while maintaining overall spectrum utilization efficiency.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If user terminals are equipped with dual transceivers for FDD and TDD, then access to both band types is enabled, but device complexity and cost increase

Engineering Contradiction:
Improvefrequency band access capabilityVSAvoidtransceiver configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the existing FDD user terminal universally compatible with both FDD and TDD networks by adding control logic that enables the single transceiver to operate on TDD bands. This multi-functionality approach allows the terminal to access both frequency band types without requiring separate dedicated transceivers, thus avoiding increased device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2020097B1Device and control procedure for fdd and non-fdd bandwidth
Publication Date: 2015.01.28 ALCATEL LUCENT SA
  • EP2020097B1 patent drawingFigure 1~2

AI summary

A device (D) dedicated to control of bandwidth used by a work station (3-j) that can be connected to a network allowing the user to access a service that doesn't require feedback, this network being a frequency division duplexing network which accommodates at least one frequency bundle branch block of the first type, dedicated to transmission of data bundles, and a second type distinct from the first type. This device has i) the capacity to analyze at least signaling information received from the work station on the first type block, and ii) a switchover feature which is activated if the analysis device detects signaling information signaling the availability of a service on a second type frequency block range, to receive second type data stream on the second type frequency block.