Random Access
Christopher Cox · 2012
The base station explicitly schedules all transmissions that a mobile carries out on a physical uplink shared channel (PUSCH). If the mobile wishes to transmit on the PUSCH but does not have the resources to do so, then it usually sends a scheduling request on a physical uplink control channel. If it does not have the resources to do that, then it initiates a random access procedure. The random access procedure is used for data transmission and reception. The procedure begins when the mobile transmits a random access preamble on a physical random access channel (PRACH). This initiates an exchange of messages between the mobile and the base station that has two main variants, non contention based and contention based. Controlled Vocabulary Terms Data communication; multiaccess communication; reception; uplink