UMTS Layer 3

RRC is located at Layer 3 in the control plane of the access stratum (AS). It resides in
the UE and the UTRAN – at the Node B (UE in idle mode) or SRNC (UE in connected
mode). RRC provides signalling transfer services to higher layers through service
access points (SAP). Higher layer signalling messages are encapsulated within RRC
messages for transmission over the radio interface. NAS higher layer entities using
the services of RRC in this way are:
• Call Control (CC), which deals with set-up, maintenance and clear-down of circuitswitched
calls.
• Session Management (SM), which deals with set-up, maintenance and clear-down
of pocket-switched sessions.
• Mobility Management (MM), which deals with all mobility issues involving tracking of
UEs as they move from area to area. Related to this is GPRS Mobility Management
(GMM) which does the same for packet-mode operation.
• Short Message Service (SMS), dealing with SMS message delivery.


Layer 3 pdf


source : m2vtelecom.blogspot.com