Methods and devices for access control, user equipment and base stations

A method of access control, being applied to a base station supporting new radio access to an unlicensed spectrum, comprising:

• determining a first system information block based on a supported traffic type, wherein the first system information block carries at least one of:
• a correspondence between traffic type and maximum number of times for transmitting a preamble or a correspondence between quality of service class identifier and maximum numbers of times for transmitting a preamble;
• and
• broadcasting the first system information block.

User equipment, comprising:

• a processor;
• and
• memory for storing processor executable instructions;
• wherein the processor is configured to:
• determine a result of listen-before-talk (LBT) detection on a to-be-detected channel, wherein the to-be-detected channel is an unlicensed channel for sending a random access preamble;
• increase a preamble transmission counter by one in response to that the result of the LBT detection indicates a failure, and determining a count value of the preamble counter;
• and
• perform radio link failure processing in response to that the count value of the preamble transmission counter reaches a maximum number of times for transmitting the preamble, wherein maximum number of times for transmitting the preamble and traffic type of a to-be-transmitted traffic have a correspondence, or service class identifier of a to-be-transmitted traffic have a correspondence.