ss with contention The mobile transmits the preamble in the PRACH physical channel. This preamble is chosen randomly in a list communicated by the eNB entity in the SIB2 system information. VoLTE and ViLTE In case the eNB entity does not respond, the mobile retransmits the preamble while increasing the transmission power. The maximum number of retransmissions is shown by the SIB2 system information or the RRC Connection Reconfiguration message. The risk of contention is linked to the fact that several mobiles can access the same PRACH physical channel and use the same preamble. When the eNB entity receives the PRACH physical channel, it calculates the timing advance and transmits to the mobile: - the DCI control information in the PDCCH physical channel, recovered from random access RNTI (RA-RNTI) identity. The mobile retrieves the description of its data in the PDSCH physical channel; - the random access response (MAC RAR) frame containing the index of the preamble, the timing advance TA, the resource to use (UL Grant) for the transmission in the PUSCH physical channel and the temporary cell RNTI (TC-RNTI) identity. This identity is temporary as several mobiles may consider that this identity is allocated to them, thereby leading to contention. The mobile initializes its timing advance and responds with the RRC Connection Request message containing: - the shortened temporary mobile subscriber identity (S-TMSI), if the mobile is already attached; - a random number in the contrary case. When the eNB entity receives the RRC Connection Request message, it transmits to the mobile: - the DCI control information in the PDCCH physical channel, recovered from the TC-RNTI identity. The mobile retrieves the description of its data in the PDSCH physical channel; - the header MAC RAR containing the UE CRI (contention resolution identity) control element. This control element reproduces the identity in the RRC Connection Request message, thereby resolving the contention issue; - the RRC ConnectionSetup message. The TC-RNTI id