Method and apparatus for performing contention based random access at carrier frequency

摘要

The method and user equipment comprise receiving 602 an indication from the network entity whether the cell at the carrier frequency supports a two-step random access procedure. When a two-step random access procedure is supported in a cell (604), a random access procedure is selected between the two-step random access procedure and the four-step random access procedure (606), and each of the two- and four-step random access procedures is one or more. And a preamble, wherein the one or more preambles are configured to be associated with one of the two or four stage random access procedures in the cell. A preamble is randomly selected and transmitted from one or more preambles associated with the selected random access procedure (608), and a time-frequency resource is determined based on the transmitted preamble. Physical random access channel carrier data comprising a demodulation reference signal and one or more data symbols is transmitted 610 on the determined time-frequency resource.