Short Contention Resolution ID for Faster NB-IoT Random Access
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Solution Overview
Problem
Existing NB-IoT networks face inefficiencies in random access procedures due to the need for large contention resolution identifiers, leading to excessive signaling and resource allocation, especially for small data transmissions.
Innovation Solution
Implementing a shorter contention resolution identifier, typically 16 bits, for use on the physical downlink control channel (PDCCH) to terminate the random access channel procedure without requiring the physical shared data channel (PDSCH), allowing early data transmission and reducing the need for additional acknowledgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a long contention resolution identifier is used in NB-IoT random access procedures, then the identifier can uniquely identify user equipment, but the signaling overhead and resource allocation increase excessively
Solution Approach 1:
The contention resolution identifier transmission is segmented into two parts: a shortened identifier (e.g., 16 bits) transmitted on the PDCCH for quick recognition, and the full identifier transmitted on the PDSCH when needed. This segmentation allows the system to use minimal signaling for common cases while maintaining full identification capability when required.
Solution Approach 2:
The patent applies partial action by transmitting only a portion of the contention resolution identifier (the essential short form) on the PDCCH, which is sufficient for most random access procedures. The complete identifier is transmitted only when actually needed, avoiding unnecessary signaling overhead while maintaining identification reliability.
2Reliability
If the complete contention resolution identifier is transmitted on PDSCH, then all user equipment can be uniquely identified, but the random access procedure duration increases
Solution Approach 1:
The shortened contention resolution identifier is transmitted preliminarily on the PDCCH before the full identifier transmission on PDSCH. This preliminary action allows user equipment to quickly recognize and process the contention resolution result, reducing the overall procedure duration while maintaining accurate identification through the subsequent full identifier transmission if needed.
3Reliability
If traditional random access procedures are used for small data transmissions, then all standard procedures are followed, but network resources are wasted on unnecessary PDSCH allocation
Solution Approach 1:
The patent extracts the essential contention resolution function from the traditional complete random access procedure by transmitting the shortened identifier on PDCCH. This extraction allows the procedure to terminate early without requiring full PDSCH allocation, taking out only the necessary components for small data transmissions while maintaining procedural reliability.
4Reliability
If user equipment waits for application acknowledgement in all cases, then data transmission reliability is ensured, but battery consumption increases
Solution Approach 1:
The patent applies partial action by having user equipment wait for application acknowledgement only when necessary (indicated by the network through the contention resolution process), rather than in all cases. This selective approach maintains data transmission reliability when needed while reducing unnecessary battery consumption for small data transmissions that don't require full acknowledgment protocols.
Data Source
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AI summary
Various communication systems may benefit from improved random access procedures. For example, it may be helpful to improverandom access procedure when a network entity does not have any downlink data to transmit.A method, according to certain embodiments, may include receiving at a network entity from a user equipment a short contention resolution identifier. The method mayalso include transmitting from the network entity to the user equipment downlink control information comprising at least the short contention resolution identifier on a physical downlink control channel.