Detecting method, transmitting method and apparatus for common control channel

A method, comprising:

• transmitting, by a first apparatus, a first common control channel on a first resource that is a candidate resource of a first candidate resource set within downlink resources of a cell, wherein the first common control channel carries a common search space indication information indicating a candidate resource of a common search space in a second candidate resource set that is a subset of a common search space candidate resource set, wherein the common search space candidate resource set comprises at least two subsets corresponding to at least two candidate resources of the first candidate resource set;
• receiving, by a second apparatus, the first common control channel on the first resource;
• transmitting, by the first apparatus, a physical downlink control channel on the candidate resource of the common search space;
• and
• receiving, by the second apparatus, the physical downlink control channel on the candidate resource of the common search space.