Specifications

Radio Link Communications Model
Radio Frequency Channel Types
B-4 68P81095E55-E August 08, 2000
Table B-2 Medial Access Control Contents
Media Access Control Description
Secondary Control Channel (SCCH) The SCCH is an extended control path. This path is
similar to the PCCH except it does not contain a
BCCH. There may be up to 4 SCCHs per cell.
Primary Control Channel (PCCH) The logical grouping of radio link channels used to
control and monitor the integrity of the radio link.
There is one PCCH per cell. (Assigned to radio one
frequency one for each cell/sector in the system).
The frequencies are provider specific and are loaded
in a table on the mobile. The mobile scans this table
when not in active communication to determine
signal quality and receive control and short
messages (SMS).
Primary Control Channel Components
Slot Information Channel (SICH) The SICH sends outbound Slot Descriptor Blocks
(SDBs) to the SIP for allocation to Radio Link
timeslots.
Broadcast Control Channel (BCCH) The BCCH is an outbound-only path used to send
MS system parameters.
Common Control Channel (CCCH) The CCCH is an outbound-only broadcast channel
used for transmission of pages, channel
assignments, and similar controls.
Random Access Channel (RACH) The RACH is the inbound-only multiple-access
channel used to gain system access.
Non-Primary Control Channel components
Temporary Control Channel
(TCCH)
The TCCH provides temporary random access
signaling on a channel which is normally used for
reserved access.
Dedicated Control Channel (DCCH) The DCCH is allocated to an individual MS for
extended network layer control signaling
procedures.
Associated Control Channel
(ACCH)
The ACCH provides for supervision and control of
the associated traffic channel. The added bandwidth
dynamically uses the TCH.
Traffic Channel (TCH) Provides for circuit-mode transmission of user
speech and data. TCHs are reserved by individual
MSs or groups of MSs.
Packet Channel (PCH) The PCH provides for multiple-access packet-mode
transmission of user data. PCHs are accessed via a
Reservation-ALOHA protocol.