Preamble group selection in random access of wireless networks

A method for selecting a transport block size (TBS) of a first uplink message (RACH Msg3) transmitted on a Physical Uplink Shared Channel (PUSCH) during a random access procedure in a User Equipment (UE) accessing a radio access network, comprising:

• determining a pathloss threshold parameter by a base station (eNB) serving the UE;
• broadcasting the pathloss threshold parameter to a UE being served by the eNB;
• and
• receiving a random access request from the UE with an indication of a selected TBS, wherein a smaller value of TBS is selected from a set of TBS values by the UE if an estimated pathloss value indicative of radio link conditions between the UE and the eNB is greater than i an operating power level of the UE minus the pathloss threshold parameter.

A User Equipment (UE) apparatus for accessing a radio access network, the UE comprising:

• processing logic connected to a memory;
• radio frequency (RF) transmission logic coupled to the processing logic;
• and
• RF receiver logic couple to the processing logic, the RF receiving logic configured to receive a pathloss threshold parameter;
• and
• wherein the processing logic is configured to select a transport block size (TBS) of a first uplink message (RACH Msg3) transmitted on a Physical Uplink Shared Channel (PUSCH) during a random access procedure while the UE is accessing a radio access network by:
• estimating a downlink pathloss value indicative of radio link conditions between the UE and a base station (eNB) serving the UE;
• selecting from a set of TBS values a smaller value of TBS if the determined pathloss value is greater than an operating power level of the UE minus the pathloss threshold parameter;
• and
• sending a random access request via the RF transmission logic containing an indication of the selected TBS.