Patent ID: 8982868
Filing Date: 2015-03-17
Classification: H04W

Abstract:
1. A base station comprising: a transmitter configured to broadcast information for determining one or more first preambles contained in a first Random Access Preamble group and any second preamble(s) contained in a second Random Access Preamble group; and a receiver configured to receive a preamble transmitted by a mobile station; wherein the received preamble is randomly selected from among the first preamble(s) when the first Random Access Preamble group is selected, or is randomly selected from among the second preamble(s) when the second Random Access Preamble group is selected, wherein the second Random Access Preamble group is selected if a message size based on data available for transmission by the mobile station meets a first condition and if a value calculated based on a reference signal received power of downlink meets a second condition, and else the first Random Access Preamble group is selected.