Random Access Apparatus for Unlicensed Spectrum Collision Reduction
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Solution Overview
Problem
The existing random access procedures for LTE devices on unlicensed spectra face challenges due to contention and collisions, as the availability of PRACH resources on unlicensed spectra is unpredictable, leading to potential unavailability of subframes and failure in executing random access procedures.
Innovation Solution
A random access apparatus and method that allows user equipment to receive notification messages from a base station with configuration parameters for PRACH resources on unlicensed spectra, enabling the determination of available PRACH resources and the execution of random access procedures, including listening parameters for idle detection and backoff times to minimize collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If PRACH resources on unlicensed spectrum are notified by system broadcast information, then random access procedure can be executed on licensed spectrum, but subframe availability becomes unpredictable and random access may fail on unlicensed spectrum
Solution Approach 1:
The base station performs preliminary actions by monitoring the unlicensed spectrum and determining available PRACH resources before notifying the UE. The base station proactively identifies suitable subframes and resources for random access on the unlicensed spectrum, then provides this information to the UE through notification messages, ensuring the UE only attempts access on guaranteed available resources.
Solution Approach 2:
The base station continuously monitors the unlicensed spectrum and dynamically adjusts PRACH resource availability information based on real-time conditions. This feedback mechanism allows the system to adapt to changing spectrum conditions, ensuring that the notified PRACH resources remain valid and available when the UE attempts random access.
2Speed
If random access code is sent on unlicensed spectrum without availability checking, then access speed is improved, but collision probability increases
Solution Approach 1:
The UE performs preliminary listening on the unlicensed spectrum before sending the random access code. By checking the channel availability in advance (LBT - Listen Before Talk), the UE ensures the spectrum is idle before transmitting, thereby maintaining fast access when conditions permit while avoiding collisions when the channel is busy.
Solution Approach 2:
The UE applies preliminary anti-action by detecting channel occupancy and preventing transmission when the unlicensed spectrum is already in use. This preemptive measure counteracts the potential harmful effect of collisions by stopping transmission before interference occurs, while still allowing rapid access when the channel is clear.
Data Source
AI summary
Embodiments of the present invention provide random access user equipment, including: a receiving module, configured to receive a notification message sent by a base station, where the notification message is used to instruct the user equipment UE to execute a random access procedure; a processing module, configured to determine, according to a configuration parameter in the notification message received by the receiving module, a PRACH resource used to execute the random access procedure; and a sending module, configured to send a random access code to the base station on the PRACH resource determined by the processing module; where the receiving module is configured to receive a random access response message sent by the base station. The embodiments of the present invention further provide a random access method. The present invention has an advantage that executing the random access procedure on an unlicensed spectrum can be implemented.