IOPS Cell Isolation for MBMS Service Quality

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Solution Overview

Problem

In radio networks providing group communication using MBMS in MBSFN transmission mode, the quality of service is dependent on stable radio base stations, and the resilience feature IOPS causes performance challenges such as unknown cells not contributing to MBSFN, radio interference between IOPS and non-IOPS cells, and unpredictable user experiences during handovers.

Innovation Solution

Wireless devices report the presence of IOPS cells to a central GC control node, which informs other devices about the proximity of IOPS cells, providing details like PLMN ID to improve handover times and access to local GC servers, thus enhancing MBMS quality and user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If IOPS mode is activated to provide local connectivity and resilience, then service availability is improved during backhaul failure, but radio interference increases and MBSFN quality degrades

Engineering Contradiction:

Improveservice availabilityVSAvoidradio interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the IOPS cell from the MBSFN transmission system by preventing it from participating in synchronized multicast transmissions. The IOPS cell is isolated from the coordinated multi-cell transmission, allowing it to provide local connectivity without interfering with the MBSFN signal quality. This is achieved by excluding IOPS cells from the MBSFN synchronization protocol while maintaining their ability to provide unicast services.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The network is segmented into two distinct operational modes: MBSFN cells that participate in synchronized multicast transmission and IOPS cells that operate independently for local connectivity. This segmentation allows each cell type to optimize its function without compromising the other, with IOPS cells handling local resilience and MBSFN cells maintaining broadcast quality.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If IOPS cells are excluded from MBSFN transmission, then radio interference is reduced, but coverage area decreases

Engineering Contradiction:

Improveradio interferenceVSAvoidcoverage area

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent implements multi-functionality by enabling wireless devices to operate in multiple modes: they can receive MBSFN transmissions from non-IOPS cells for broad coverage and simultaneously establish unicast connections with IOPS cells for local service continuity. This allows the system to maintain extensive coverage through MBSFN while providing reliable local service through IOPS without mutual interference.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If wireless devices switch between IOPS and non-IOPS cells, then mobility is maintained, but user experience becomes unpredictable

Engineering Contradiction:

ImprovemobilityVSAvoiduser experience consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where the network monitors device location and IOPS cell status, then proactively provides notification messages to devices about upcoming IOPS cell encounters. This feedback allows devices to prepare for mode transitions, maintaining consistent user experience by warning users before service characteristics change during handovers between IOPS and non-IOPS cells.

Inventive Principle:

Principle #23Feedback

4Productivity

If MBSFN transmission is used for efficient group communication, then network efficiency is improved, but service quality becomes dependent on stable base station sets

Engineering Contradiction:

Improvenetwork efficiencyVSAvoidservice quality stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent extracts IOPS cells from the MBSFN base station set, creating a separate operational category. This ensures that the MBSFN transmission group consists only of stable, synchronized base stations that can reliably maintain multicast quality, while IOPS cells provide supplemental unicast services without compromising the integrity of the MBSFN transmission ensemble.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS12144006B2Isolated E-UTRAN operations for public safety (IOPS) awareness with multimedia broadcast multicast services (MBMS)

Publication Date: 2024.11.12 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Disclosed herein is a method for reporting existence of an isolated radio access network and a wireless device and a radio base station for performing the method. The method comprises: performing communications in an isolated radio access network, the isolated radio access network being a radio access network provided by one or more first radio base stations that do not have connectivity to a centralized core network of a cellular communications network; attaching to a second radio base station, the second radio base station having connectivity to the core network; and providing, to a centralized communications server via the second radio base station, one or more messages that inform the centralized communications server of the existence of the isolated radio access network.