TABLE OF CONTENTS We turn now to the most important subject of this chapter: the RRC. The RRC controls the configuration of the lower layers in the protocol stack, and it has control interfaces to each of the lower layers (PDCP, BMC, RLC, MAC, and layer 1).
The RRC provides the following services to the upper layers:
General control. This is an information broadcast service. The information transferred is unacknowledged, and it is broadcast to all mobiles within a certain area.
Notification. This includes paging and notification broadcast services. The paging service broadcasts paging information in a certain geographical area, but it is addressed to a specific UE or UEs. The notification broadcast service is defined to provide information broadcast to all UEs in a cell or cells. Note that the notification broadcast service seems to be quite similar to the general control service.
Dedicated control. This service includes the establishment and release of a connection and the transfer of messages using this connection. These connections can be both point-to-point and group connections. Message transfers are acknowledged.
The RRC functions include:
Initial cell selection and cell reselection (includes preparatory measurements);
Broadcast of information (system information blocks [SIBs]);
Reception of paging and notification messages;
Establishment, maintenance, and release of RRC connection;
Establishment, reconfiguration, and release of radio bearers;
Assignment, reconfiguration, and release of radio resources for the RRC connection, which includes such things as the assignment of codes and CPCH channels;
