Reference Manual

Table Of Contents
Call Control
Example:
P003013A
OLD NEW
BSC
1.
2.
3.
3.
MS
Figure 85 Transmission of physical information
1. BSC sends a message to the MS through the old RBS containing
information about the frequency and time slot to change to. This
information is sent over FACCH.
2. The MS tunes to the new frequency, and transmits handover access
bursts in the correct time slot. The access bursts are small enough to be
sent without any Timing Advance information and do not disturb any
other call.
3. (This function) RBS detects the handover access bursts and measures
the delay. The delay gives information about the Timing Advance
which is included in the Physical Information to the MS and the
Handover Detection message to BSC.
20.5 RF Channel Release
Purpose
To release a radio channel which is no longer needed.
Precondition and Initiation
See Channel Activation above.
The function is initiated when the RBS receives a Channel_Release
message from BSC.
Description
All trafc and signalling on a group of dedicated logical channels are
stopped, and all associated resources are released. After having released
the channel, or if the channel is already released, the RBS sends an
RF_Channel_Acknowledge message to BSC /GSM 08.58:4.7/.
EN/LZT 720 0008 R1A
2001-06-26
197 (421)
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