GSM A interface - BSS Application PartThe A interface is located between the MSC (mobile service switching centre) and the BSS (base station system or radio sub-system).

Standard reference: GSM 08-08 § 2, MSC to BSS - Layer 3

The A interface supports several Applications Parts:

BSSMAP : Base Station System Management Application Part. DTAP : Direct Transfer Application Part.

o RR:Radio Resources.

o MM:Mobility Management.

o CC:Call Control.

BSSMAP messages

Standard reference: GSM 08-08 § 3, MSC to BSS - Layer 3

BSSMAP messages (Base Station System Management Application Part), for a GSM A interface located between the MSC (mobile service switching centre) and the BSS (base station system or radio sub-system) are listed and ordered according to their hexadecimal code or their type (abreviation).

Message list: hex codes

Code Abreviation BSSMAP: message designation01 ASS-REQ Assignment request.02 ASS-COM Assignment complete.03 ASS-FAIL Assignment failure.20 CLEAR-COM Clear command.21 CLEAR-COMP Clear complete.22 CLEAR-REQ Clear request.23 SAPI-CL-COM SAPI "n" clear request.24 SAPI-CL-COMP SAPI "n" clear complete.25 SAPI-REJ SAPI "n" rejected.30 RESET Reset.

31 RESET-ACK Reset acknowledge.32 OVERLOAD Overload.33 TRACE-INV Trace investigation.34 RESET-CIR Reset circuit.35 RST-CI-ACK Reset circuit acknowledge.40 BLOCK Resource blocked.41 BLOCK-ACK Acknowledgement resource blocked.42 UNBLOCK Resource un-blocked.43 UNBLOCK-ACK Acknowledgement resource un-blocked.50 RESOURC-REQ Resource request.51 RESOURC-IND Resource indication.52 PAGING Paging.53 CYPHER-COM Cypher mode command.54 CLASS-UPD "Classmark" update.55 CYPHER-COMP Cypher mode complete.56 QUEUEING-IN Queuing-in.57 LAYER-3-INF Layer 3 information.80 HAND-REQ Handover request.81 HAND-RQD Handover requested.82 HND-RQ-ACK Handover request acknowledge.83 HAND-COM Handover command.84 HAND-COMP Handover complete.86 HAND-FAIL Handover failure.87 HAND-PERFORM Handover performed.88 HND-CAND-ENQ Handover candidate enquiry.89 HND-CAND-REQ Handover candidate request.8A HAND-REQ-REJ Handover request rejection.8B HAND-DETECT Handover detection.

Message list: types

Abreviation Code BSSMAP: message designationASS-COM 02 Assignment complete.ASS-FAIL 03 Assignment failure.ASS-REQ 01 Assignment request.BLOCK 40 Resource blocked.BLOCK-ACK 41 Acknowledgement resource blocked.CLASS-UPD 54 "Classmark" update.CLEAR-COM 20 Clear command.CLEAR-COMP 21 Clear complete.CLEAR-REQ 22 Clear request.CYPHER-COM 53 Cypher mode command.CYPHER-COMP 55 Cypher mode complete.HAND-COM 83 Handover command.HAND-COMP 84 Handover complete.

HAND-DETECT 8B Handover detection.HAND-FAIL 86 Handover failure.HAND-PERFORM 87 Handover performed.HAND-REQ 80 Handover request.HAND-REQ-REJ 8A Handover request rejection.HAND-RQD 81 Handover requested.HND-CAND-ENQ 88 Handover candidate enquiry.HND-CAND-REQ 89 Handover candidate request.HND-RQ-ACK 82 Handover request acknowledge.LAYER-3-INF 57 Layer 3 information.OVERLOAD 32 Overload.PAGING 52 Paging.QUEUEING-IN 56 Queuing-in.RESET 30 Reset.RESET-ACK 31 Reset acknowledge.RESET-CIR 34 Reset circuit.RESOURC-IND 51 Resource indication.RESOURC-REQ 50 Resource request.RST-CI-ACK 35 Reset circuit acknowledge.SAPI-CL-COM 23 SAPI "n" clear request.SAPI-CL-COMP 24 SAPI "n" clear complete.SAPI-REJ 25 SAPI "n" rejected.TRACE-INV 33 Trace investigation.UNBLOCK 42 Resource un-blocked.UNBLOCK-ACK 43 Acknowledgement resource un-blocked.

DTAP Call Control messages

Standard reference: GSM 04-08 § 5, §9.3, §10.4, MSC to BSS - Layer 3

DTAP (Direct Transfer Application Part) Call Control messages , for a GSM A interface located between the MSC (mobile service switching centre) and the BSS (base station system or radio sub-system) are listed and ordered according to their hexadecimal code or their type (abreviation).

Message list: hex codes

Code Abreviation DTAP Call Control message01 ALERTING Alerting.02 CALL-PROCEED Call proceeding.03 PROGRESS Progress.05 SETUP Setup.07 CONNECT Connect.08 CALL-CONFIRM Call confirmed.0D EMERG-SETUP Emergency setup.0F CONNECT-ACK Connect acknowledged.

10 USER-INFO User information.13 MODIFY-REJ” Modify reject.17 MODIFY Modify1F MODIFY-COMP Modify complete.25 DISCONNECT Disconnect.2A RELEASE-COMP Release complete.2D RELEASE Release.31 STOP-DTMF Stop DTMF.32 STOP-DTMF-ACK Stop DTMF acknowledge.34 STATUS-ENQ Status enquiry.35 START-DTMF Start DTMF.36 START-DTMF-AC Start DTMF acknowledge.37 START-DTMF-RE Start DTMF reject.39 CONGEST-CTRL Congestion control.3D STATUS Status.3E NOTIFY Notify.

Message list: types

Abreviation Code DTAP Call Control messageALERTING 01 Alerting.CALL-CONFIRM 08 Call confirmed.CALL-PROCEED 02 Call proceeding.CONGEST-CTRL 39 Congestion control.CONNECT 07 Connect.CONNECT-ACK 0F Connect acknowledged.DISCONNECT 25 Disconnect.EMERG-SETUP 0D Emergency setup.MODIFY 17 ModifyMODIFY-COMP 1F Modify complete.MODIFY-REJ” 13 Modify reject.NOTIFY 3E Notify.PROGRESS 03 Progress.RELEASE 2D Release.RELEASE-COMP 2A Release complete.SETUP 05 Setup.START-DTMF 35 Start DTMF.START-DTMF-AC 36 Start DTMF acknowledge.START-DTMF-RE 37 Start DTMF reject.STATUS 3D Status.STATUS-ENQ 34 Status enquiry.STOP-DTMF 31 Stop DTMF.STOP-DTMF-ACK 32 Stop DTMF acknowledge.USER-INFO 10 User information.

DTAP Radio Resources Management messages

Standard reference: GSM 04-08 § 3, §9.1, §10.4, MSC to BSS- Layer 3

DTAP (Direct Transfer Application Part) Radio Resources Management messages , for a GSM A interface located between the MSC (mobile service switching centre) and the BSS (base station system or radio sub-system) are listed and ordered according to their hexadecimal code or their type (abreviation).

Message list: hex codes

Code Abreviation DTAP Radio Resources Management0A PARTIAL-REL Partial release.0D CHANNEL-REL Channel release.0F PART-REL-COM Partial release complete.10 CHAN-MODIFY Channel mode modify.12 RR-STATUS RR status.14 FREQ-REDEF Frequency redefinition.15 MEASUR-REP Measurement report.16 CLASSM-CHG Classmark change.17 CHAN-MOD-ACK Channel mode modify acknowledge.19 SYS-INFO-T1 System information type 1.1A SYS-INFO-T2 System information type 2.1B SYS-INFO-T3 System information type 3.1C SYS-INFO-T4 System information type 4.1D SYS-INFO-T5 System information type 5.1E SYS-INFO-T6 System information type 6.21 PAG-REQ-T1 Paging request type 1.22 PAG-REQ-T2 Paging request type 2.24 PAG-REQ-T3 Paging request type 3.26 ASS-COMMAND Assignment command.27 PAGING-REP Paging response.28 HAND-FAILURE Handover failure.29 ASS-COMPLETE Assignment complete.2B HAND-COMM Handover command.2C HAND-COMP Handover complete.2D PHYS-INFO Physical layer information.2F ASS-FAILURE Assignment failure.32 CIPH-M-COMP Ciphering mode complete.35 CIPH-M-COMM Ciphering mode command.39 IMM-ASS-EXT Immediate assignment extended.3A IMM-ASS-REJ Immediate assignment reject.3B ADD-ASS Additional assignment.3F IMM-ASS Immediate assignment.

Message list: types

Abreviation Code DTAP Radio Resources ManagementADD-ASS 3B Additional assignment.ASS-COMMAND 26 Assignment command.ASS-COMPLETE 29 Assignment complete.ASS-FAILURE 2F Assignment failure.CHAN-MOD-ACK 17 Channel mode modify acknowledge.CHAN-MODIFY 10 Channel mode modify.CHANNEL-REL 0D Channel release.CIPH-M-COMM 35 Ciphering mode command.CIPH-M-COMP 32 Ciphering mode complete.CLASSM-CHG 16 Classmark change.FREQ-REDEF 14 Frequency redefinition.HAND-COMM 2B Handover command.HAND-COMP 2C Handover complete.HAND-FAILURE 28 Handover failure.IMM-ASS 3F Immediate assignment.IMM-ASS-EXT 39 Immediate assignment extended.IMM-ASS-REJ 3A Immediate assignment reject.MEASUR-REP 15 Measurement report.PAG-REQ-T1 21 Paging request type 1.PAG-REQ-T2 22 Paging request type 2.PAG-REQ-T3 24 Paging request type 3.PAGING-REP 27 Paging response.PART-REL-COM 0F Partial release complete.PARTIAL-REL 0A Partial release.PHYS-INFO 2D Physical layer information.RR-STATUS 12 RR status.SYS-INFO-T1 19 System information type 1.SYS-INFO-T2 1A System information type 2.SYS-INFO-T3 1B System information type 3.SYS-INFO-T4 1C System information type 4.SYS-INFO-T5 1D System information type 5.SYS-INFO-T6 1E System information type 6.

DTAP Mobility Management messages

Standard reference: GSM 04-08 § 4, §9.2, §10.4, MSC to BSS - Layer 3

DTAP (Direct Transfer Application Part) Mobility Management messages , for a GSM A interface located between the MSC (mobile service switching centre) and the BSS (base station system or radio sub-system) are listed and ordered according to their hexadecimal code or their type (abreviation).

Message list: hex codes

Code Abreviation DTAP Mobility Management message

01 IMSI-DET-IND IMSI detach indication.02 LOC-UPD-ACC Location updating accept.04 LOC-UPD-REJ Location updating reject.08 LOC-UPD-REQ Location updating request.11 AUTHENT-REJ Authentication reject.12 AUTHENT-REQ Authentication request.14 AUTHENT-RESP Authentication response.18 IDENTITY-REQ Identity request.19 IDENTITY-RESP Identity response.1A TMSI-REA-COMM Temporary mobile identity reallocation command.1B TMSI-REA-COMP Temporary mobile identity reallocation complete.21 CM-SERV-ACC Connection management service accept.22 CM-SERV-REJ Connection management service reject.26 CM-SERV-REQ Connection management service request.28 CM-REESTABL Connection management re-establishment request.31 MM-STATUS Status.

Message list: types

Abreviation Code DTAP Mobility Management messageAUTHENT-REJ 11 Authentication reject.AUTHENT-REQ 12 Authentication request.AUTHENT-RESP 14 Authentication response.CM-REESTABL 28 Connection management re-establishment request.CM-SERV-ACC 21 Connection management service accept.CM-SERV-REJ 22 Connection management service reject.CM-SERV-REQ 26 Connection management service request.IDENTITY-REQ 18 Identity request.IDENTITY-RESP 19 Identity response.IMSI-DET-IND 01 IMSI detach indication.LOC-UPD-ACC 02 Location updating accept.LOC-UPD-REJ 04 Location updating reject.LOC-UPD-REQ 08 Location updating request.MM-STATUS 31 Status.TMSI-REA-COMM 1A Temporary mobile identity reallocation command.TMSI-REA-COMP 1B Temporary mobile identity reallocation complete.