The present disclosure provides a method in a User Equipment of transmitting a random access preamble and a physical uplink shared channel, comprising: determining a resource size to be used to contain the physical uplink shared channel, the resource size being one of a set of predetermined sizes; identifying a resource to be used from a predetermined set of resources, the resource in the set of resources corresponding to the determined resource size, each resource being identified with a respective first index n and occupying a distinct set of OFDM symbols and subcarriers; identifying a PRACH preamble with a second index n' corresponding to the first index n of the identified resource; and transmitting the identified PRACH preamble, and the physical uplink shared channel in the identified resource.