A method and system for detecting radio link (RL) failures between a wireless transmit/receive unit (WTRU) and a Node-B are disclosed. When signaling radio bearers (SRBs) are supported by high speed uplink packet access (HSUPA), an RL failure is recognized based on detection of improper operation of at least one of an absolute grant channel (AGCH), a relative grant channel (RGCH), a hybrid-automatic repeat request (H-ARQ) information channel (HICH), an enhanced uplink dedicated physical control channel (E-DPCCH) and an enhanced uplink dedicated physical data channel (E-DPDCH). When SRBs are supported by high speed downlink packet access (HSDPA), an RL failure is recognized based on detection of improper operation of at least one of a high speed shared control channel (HS-SCCH), a high speed physical downlink shared channel (HS-PDSCH) and a high speed dedicated physical control channel (HS-DPCCH).