RA-RNTI Generation Using Multi-Counter Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In NB-IoT radio network systems, the existing method for generating Random Access-Radio Network Temporary Identifiers (RA-RNTIs) faces issues such as wrap-around problems and collisions, especially in TDD mode, due to limited resource availability and extended coverage areas, leading to inefficient use of RA-RNTI values.

Innovation Solution

A wireless device and access network node configuration that uses multiple counters to determine RA-RNTIs based on System Frame Number (SFN) and Hyper Frame Number (HFN), ensuring a uniform distribution of RA-RNTI values and avoiding collisions by reallocating unused RA-RNTIs to other RNTI types, thereby expanding the identifier space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the existing RA-RNTI generation method based on SFN is used, then the implementation is simple, but wrap-around problems and collisions occur in TDD mode due to limited resource availability and extended coverage areas

Engineering Contradiction:
ImproveRA-RNTI uniquenessVSAvoidcounter management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The time counter is segmented into multiple counters with different time granularities (first counter for shorter intervals, second counter for longer intervals). This segmentation allows the system to track time more precisely without requiring a single large counter that would wrap around frequently, thereby ensuring RA-RNTI uniqueness while managing complexity through modular counter structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-dimensional SFN counter to a multi-dimensional counter system with multiple counters operating at different time scales. This dimensional expansion allows the system to generate unique RA-RNTI values over extended periods without wrap-around issues, as the combination of multiple counter values creates a larger effective address space.

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

2Reliability

If multiple counters are introduced to ensure uniform distribution of RA-RNTI values, then collision problems are avoided, but the device complexity increases

Engineering Contradiction:
ImproveRA-RNTI distribution uniformityVSAvoidcounter management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The counter system is designed to be dynamically activated based on operational conditions. The first counter operates during normal conditions, while the second counter is engaged when extended coverage or TDD mode is detected. This dynamic approach ensures uniform RA-RNTI distribution where needed while minimizing complexity in scenarios where simple SFN-based generation suffices.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the temporal parameters of counter operation to match different deployment scenarios. By adjusting counter increment rates, wrap-around thresholds, and activation conditions based on coverage requirements and TDD/FDD configuration, the system achieves uniform RA-RNTI distribution adaptively without permanently increasing complexity.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If the SFN wrap-around is allowed to occur, then the system operates continuously, but RA-RNTI collisions increase in extended coverage areas

Engineering Contradiction:
Improvesystem operation continuityVSAvoidRA-RNTI collision avoidance
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The system performs preliminary detection of TDD mode and extended coverage conditions before RA-RNTI generation. When these conditions are detected, the appropriate multi-counter mechanism is pre-configured and activated, preventing wrap-around collisions before they occur. This preliminary action maintains system continuity while proactively avoiding collision scenarios.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The second counter acts as an intermediary that bridges the gap between SFN wrap-around events. By introducing this intermediate time-tracking mechanism, the system can detect when SFN is approaching wrap-around and adjust RA-RNTI generation accordingly, preventing collisions while maintaining continuous operation. The intermediary counter absorbs the wrap-around issue rather than allowing it to cause collisions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3979755B1Technique for generating rntis
Publication Date: 2024.01.31 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3979755B1 patent drawingFigure 1
  • EP3979755B1 patent drawingFigure 2
  • EP3979755B1 patent drawingFigure 3

AI summary

A wireless device is provided that is configured to determine a Random Access-Radio Network Temporary Identifier, RA-RNTI, for use in a radio network system. The wireless device comprises a subframe counter configured to be incremented after a pre-defined period of time and to be re-set when having reached a predefined first number, a system frame number counter, SFN_id, configured to be incremented when the subframe counter reaches the predefined first number and to be re-set when having reached a predefined second number, and a hyper frame number, H-SFN, counter configured to be incremented when the SFN_id reaches the predefined second number and to be re-set when having reached a predefined third number. The wireless device is configured to determine an RA-RNTI at least based on the SFN_id and the H-SFN counter.