LTE & LTE Advanced

10Radio Interface Procedures

10.1. Access control

10.1.1. PRACH physical channel acquisition

The procedure of access to the evolved Node B (eNB) entity is developed for accessing Physical Random Access Channel (PRACH) that the mobile is going to use to carry out the random access.

The different physical channels and physical signals processed by the mobile for the acquisition of the PRACH physical channel can be found in Table 10.1.

Table 10.1. Acquisition of the PRACH physical channel

The Primary Synchronization Signal (PSS) facilitates the following functions:

• – frequency synchronization;
• – time synchronization at the level of the Orthogonal Frequency Division Multiplexing (OFDM) symbol, of the time slot (periodicity 0.5 ms), of the subframe (periodicity 1 ms) and the half-frame (periodicity 5 ms);
• – determination of the value of the number .

The Secondary Synchronization Signal (SSS) facilitates the following functions:

• – time synchronization at the frame level (periodicity 10 ms);
• – determination of the Frequency Division Duplex (FDD) or Time Division Duplex (TDD) mode;
• – determination of the type of the Cyclic Prefix (CP), normal or extended;
• – determination of the value of the number .

The number of the Physical-layer Cell Identity (PCI) is equal to

represents the ...