A base station is configured to communicate employing a plurality of carriers comprising at least one prime carrier and at least one non-prime carrier. The base station may transmit a system frame number in a physical broadcast channel in a frame on a prime carrier. The base station may transmit and receive, employing a communication interface, packets in the frames on a non-prime carrier. The communication interface employs the system frame number transmitted in the frame of the prime carrier. The non-prime carrier is configured to operate without broadcasting the system frame number on the non-prime carrier.