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A-13
APPENDIX A
Protocol Log of a Typical Call
Protocol Log of a Typical Call
For brevity, the protocol log shown in the User’s Guide is in a shorter form than that
presented by the HP/Agilent 37900D GSM 04.08 decoding option.
This is a protocol log of the Common Air Interface (CAI) for a typical call placed
between the Agilent 8922M/S and a GSM Mobile Station. You are expected to be
familiar with ETSI standards GSM 04.06 and 04.08 to understand these protocol
logs. The logs are in a simplified format and contain the following information:
Source Layer -> Destination Layer,
PRIMITIVE,
Logical Channel (if any),
Data Link Frame Header,
Layer 3 Message Type,
Layer 3 Message Contents in hexidecimal,
TDMA Frame number.
The Service Access Points (SAP) in the BS (Agilent 8922M/S) that are recorded
are:
Between CC and MM,
Between MM and RR,
Between RR and DL,
Between DL and PH.
The call is BS originated to a class II MS. Authentication and encryption are not
used. The initial TCH is full rate on ARFCN 30 using timeslot 4. The intra-cell
handover is to a hopping TCH using ARFCN 10, 62 and 114 with MAIO set to zero
using timeslot 6. The inter-cell handover is back to the ARFCN 30 timeslot 4 TCH.
The call is BS terminated. The BCCH/CCCH is using SD/4 organization on ARFCN
20. Paging mode is normal and DTX is off. Requested MS transmit level is 15. This
is an early assignment call without use of start times. The MS in this case is using
DL I frames for acknowledgement rather than \‘piggybacking\’ acknowledgement
on following DL I frames. This is a Phase I MS and therefore only BM0 format BA,
CA and MA tables are used.
Uplink traffic is in bold typeface, downlink traffic is in normal typeface.