Specifications

Radio Link Communications Model
Radio Frequency Channel Types
B-6 68P81095E55-E August 08, 2000
Control Channels
Primary Control Channel
The Primary Control Channel (PCCH) is used to transfer most important call control
and mobility management information between the MS and the EBTS. Each provider
specifies a set of leased frequencies as primary control channels. These channels are
assigned to radio-one, frequency-one of each sector. These frequencies are loaded
into a table on each MS for the subscriber and are used to locate and contact the MS
while it is active in the system. The MS scans the PCCH frequencies to measure
signal quality and maintain contact with the system. Both Dispatch and Interconnect
call processing use the PCCH to contact the MS. The MS uses the PCCH to contact
the network. Registration, Mobility Management, Hails, Requests-for-Service, and
Service Permissions are conducted on the PCCH. The information handled by the
PCCH is summarized in Table B-3.
Table B-3 Primary Control Channel Contents
Secondary Control Channel
Limiting factors to the capacity in a large sector or cell is control channel traffic and
the ability of the Primary Control Channel (PCCH) to handle system messages.
During Dispatch calling only, when the capacity of a site is increased, the number of
messages per control channel may become high enough to require additional control
channels. The Secondary Control Channel (SCCH) is allocated one or more timeslots
on any Base Radio. Secondary Control Channels are configured on a per cell basis.
There may be 0-4 SCCHs per cell. A SCCH is similar to the PCCH, but it does not
contain the mobility management information of the BCCH (Table B-4).
Table B-4 Secondary Control Channel Contents
Channel Contents
Inbound to MS (downlink)
Random Access Control Channel (RACH) Service requests from MSs
Outbound to EBTS (uplink)
Broadcast Control Channel (BCCH) Cell information
Cell parameters
Neighbor cell list and parameters
Location area information
Common Control Channel Paging sub-channel
Service grants
Channel Contents
Inbound to MS (downlink)
Random Access Control Channel (RACH) Service requests from MSs
Outbound to EBTS (uplink)
Common Control Channel Paging sub-channel
Service grants