Dynamic Contention Window Adjustment for Random Access Channel Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing random access procedures in wireless communication systems experience unacceptable levels of latency and signaling overhead, particularly in unlicensed spectrum access, due to contention procedures like Listen-Before-Talk (LBT), which hinder efficient channel access and network access efficiency.
Innovation Solution
The method involves an electronic device (ED) transmitting a random access preamble and dynamically adjusting the contention window size (CWS) based on the receipt of messages from a base station, setting it to a minimum value upon successful reception and increasing it upon failure, to optimize channel access priority and reduce latency and overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Listen-Before-Talk (LBT) contention procedure is used for random access in unlicensed spectrum, then channel access collision is mitigated, but latency and signaling overhead increase
Solution Approach 1:
The patent applies dynamics by making the contention window size adjustable rather than fixed. The base station dynamically configures different CWS values for different priority classes of random access preambles, allowing the system to adapt the LBT procedure parameters based on channel conditions and traffic requirements, thus reducing latency while maintaining collision mitigation
Solution Approach 2:
The patent changes the parameter of contention window size from a fixed value to a configurable parameter that can be adjusted based on priority classes. By modifying this parameter dynamically, the system optimizes the balance between collision avoidance and access speed for different types of traffic
2Reliability
If Listen-Before-Talk (LBT) contention procedure is used for random access in unlicensed spectrum, then channel access collision is mitigated, but signaling overhead increases
Solution Approach 1:
The patent reduces signaling overhead by efficiently configuring the contention window size parameter through priority class associations rather than individual RAR messages for each CWS adjustment
3Ease of manufacture
If fixed contention window size is used in LBT procedure, then implementation is simple, but channel access efficiency is reduced
Solution Approach 1:
The patent introduces dynamics by enabling flexible configuration of contention window sizes through priority classes, allowing the system to adapt to different channel conditions and traffic patterns while maintaining a manageable implementation complexity through standardized priority class definitions
Solution Approach 2:
The patent creates a universal framework where priority classes serve multiple functions: they categorize different types of traffic, determine contention window sizes, and guide random access behavior. This multi-functionality improves channel access efficiency without requiring separate mechanisms for each function
Data Source
AI summary
Method and devices are provided for a channel access mechanism for accessing a network on a random access channel (RACH). Methods involve defining a listen-before-talk (LBT) category to be used as part of a contention based procedure and how a contention window that is part of the LBT can be dynamically adjusted.