Various embodiments of the definition or configuration of a random access mapping used by a device are given below. In some embodiments, a mapping is explicitly defined in a standard. In some embodiments, a mapping may be configured in broadcasted system information. In some embodiments, a mapping was configured specifically for the device in an earlier connection to the network, for example in an embodiment where the initial access in this disclosure is part of a handover procedure, and the device was connected to the earlier connection before the handover. In some embodiments where a device is capable of multiple simultaneous connections, such as dual connectivity in LTE or multi-connectivity in future systems, a mapping is configured through an already present connection. An already present connection is on the same carrier (i.e. frequency band) as the carrier where the initial access of this disclosure occurs, in some embodiments, and on another carrier, in some embodiments.
In various embodiments, a device has obtained system information, which includes an AIT, for instance by receiving and decoding a C-AIT or by receiving a D-AIT using dedicated signaling.