Delayed data transmission in a wireless communication system after physical layer reconfiguration

For delayed transmission after reconfiguration of the physical layer, a wireless network initially sends a first message (e.g., a Reconfiguration message) to a wireless device for reconfiguration of uplink and/or downlink physical channels. The wireless network then performs synchronization to establish the uplink physical channels, and the wireless device performs synchronization to establish the downlink physical channels. Upon completing the downlink synchronization, the wireless device sends a second message (e.g., a Reconfiguration Complete message) to the wireless network. The wireless network sends a Layer 2 acknowledgment (L2 ACK) upon successfully decoding the second message. The wireless network delays transmission of signaling/data on the downlink, except for transmission of certain messages such as those needed for reconfiguration, until successful decoding of the second message. The wireless device delays transmission of signaling/data on the uplink, again except for certain messages, until recep