 1, positive indication the UE is allowed to transmit a message; 1, negative indication the UE must exit the RACH procedure. Each slot contains a 32 symbol waveform, which is scrambled with the cell primary scrambling code. Random Access Procedure: UE Required Information The preamble scrambling code is transmitted on the BCCH (SIB5), based on the parameter. The allowed signatures are based on the BCCH (SIB5) and the UE Access Service Class (ASC). For each preamble one Radio Network Planning and Optimisation of the allowed signatures is randomly selected. The UE is allowed to transmit the preamble on PRACH access slots based on the BCCH (SIB5) and the UE ASC. For the first preamble one of the allowed access slots in the next full access slot set (1 or 2) is randomly selected. For re-transmission the first allowed access slot is selected. Paging Procedures The paging procedure uses two physical channels. The paging indication (PI) is sent over the paging indication channel (PICH). The paging indication shows that the UE should read the corresponding message on the secondary common control physical channel (SCCPCH). Overview The paging procedure is required to enable the network to contact the UE in idle mode or when in connected mode the Cell_PCH and URA_PCH states. In idle mode the UE is paged over the whole location area (LA) in the case of CS paging or the routing area (RA) in the case of PS paging. This means that in idle mode the paging indication and message is sent on all cells belonging to the LA or RA. In connected mode the UE is paged over one individual cell if the UE is in the Cell_PCH state or over the UTRAN registration area if the UE is in the URA_PCH state. There are three sources that might start a paging procedure: the circuit switched core, if the UE is registered but not connected; the packet switched core, if the UE is registered but not connected; the RNC in the case where the UE is in the CELL_PCH and URA_PCH states. The paging procedure has two phases: the UE detects an indication on the PI