The document compares the call flow processes in GSM and UMTS mobile networks. In GSM, call flows involve immediate assignment of channels like SDCCH or TCH, with handovers between cells/BSCs handled through measurements and channel administration. In UMTS, call flows activate algorithms for power control, code control, and admission control. Soft handovers are supported between cells/BSCs based on measurements, with inner and outer loop power control on the downlink packet data channel.

1. Call Flow
A comparison between the call
flow in GSM and UMTS

2. Handover/Clear
Call to a MS
Paging
Call from a MS
Immediate
Assignment
Assignment /
Change of
Mode
Supervision
on
CCCH/
PCH
on
CCCH/
AGCH
Immediate assignment
of SDCCH
on
SDCCH
on
TCH
Assignment of TCH
on
RACH
Locating
Initiations
Filtering
Urgency
Basic Ranking
Aux Radio
Network
Function Eval
(HCS)
Organizing List
Sending List
Allocation Reply
MEASUREMENTS
•Immediate
Assignment
on TCH
•ACLC
•ASSOC
•AW
•CLS
•DHRA
Handover
•Inter cell/BSC
•Intra cell/BSC
•OL/UL
•Bad Quality
•Urgency
•HCS
ChannelAdministration
(SDDCH Perform.)
(Random Access)
(Assignment Fail.)
(Traffic Erlangs)
(Call Quality)
(Handover Perf.)
(Dropped Calls)
(Available TCH)
(Paging Perf.)
GSM Call Flow

3. Soft/Softer
Handover/Clear
Call to a MS
Paging
Call from a MS
RRC
Connection
RAB
Assignment
Supervision
on
PICH/
SCCPCH
on FACH/
SCCPCH Predefined Signaling
RAB Selected
on FACH/
SCCPCH
on
DPDCH
Assignment of DPDCH
on
RACH
Activate
Algorithms
Power Ctrl.
Code Ctrl.
Admission Ctrl.
RAB Selection
MEASUREMENTS
•Directed Retry
•Load Sharing
Soft Handover
•Inter cell/BSC
•Intra cell/BSC
•OL/UL
•Bad Quality
•Urgency
•HCS
InnerLoop/OuterLoop
PowerControl
(RRC Connect. Perform.)
(Random Access)
(RAB Establish. Fail.)
(Traffic Erlangs)
(Call Quality)
(Handover Perf.)
(Dropped Calls)
(Available TCH)
(Paging Perf.)
UMTS Call Flow
Open Loop
Power Control
(Throughput)

5. Open Loop on Access Channel

6. Open Loop on Access Channel