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9.2.1 Signals
Record name
From
To
Description
MSSetup
CCSetup
TBFSetup
TBFReservation
ReservationMade
ReservationResponse
FaultyChannel
IncreaseOperationCount
OutMsg
Error
MS
CC
MS
CC
CU
CC
CU
CC
CC
CC
CC
CU
CC
CU
CC
MS
CC
MS
Qtronic
Qtronic
All mobile stations are created
Connection Control is up and running
Set up a TBF
The TBF request
Best possible reservation
TBF response on the request
The removed channels
Make MS increase the operation counter
Send a text String
Send a error String
Table 9.2.1 Input and output signals in CC
9.3 Channel Utilization (CU) State Machine
It is the Channel Utilization where most of the calculation is made. The Channel Utilization
state machine manages the frame. The frame is used for holding and controlling the timeslots,
where the actual data is sent over the air interface.
Frame
timeslot 0
timeslot 1
timeslot 2
timeslot 3
Figure 9.3.1 Timeslot frame in CU
The frame can be of size four to eight, meaning that it can hold four to eight timeslots. Each
timeslot can be of type E-PDCH (Packet Data CHannel) or R-PDCH. To be able to use RTTI,
there must be at least two consecutive R-PDCHs in the frame.
Channel Utilization calculates the best possible reservation according to what capabilities the
mobile station has and how the frame is occupied and which type of PDCH it has.
During the initializing phase of the Channel Utilization state machine Qtronic will decide
how big the frame should be and which type of PDCH it should contain and where they
should be placed in the frame.
When Qtronic have decided about what the frame should look like, the Channel Utilization
state machine will be in the idle mode waiting on:
•
A signal telling Channel Utilization that the Dynamic TTI mode has changed.
•
A TBF reservation request from Connection Control.
•
A signal telling Channel Utilization that it should make a channel faulty.
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