7 Examples of structured procedures
3GPP44.056CTS radio interface layer 3 specificationGSM Cordless Telephony System (CTS), Phase 1Release 17TS
Clause 7 is informative.
7.1 General
Clause 7 contains examples of how the fixed part may group together the elementary procedures (i.e. the procedures defined in clauses 3 to 5) in order to provide normal service.
7.1.1 CTS paging request
The paging procedure is used to page a mobile station to which a connection shall be established.
Upon receipt of a CTS PAGING REQUEST message the addressed mobile station initiates the immediate assignment procedure.
Mobile Station Fixed Part
CTS PAGING REQUEST
<───────────────────────────────────────
Figure 7.1/GSM 04.56: CTS paging request
7.1.2 CTS immediate assignment
The CTS immediate assignment procedure is always initiated by the mobile station. It may be triggered by a CTS paging request or by a mobile originating service request.
The mobile station sends a CTS ACCESS REQUEST message on the Access Request Channel. The fixed part responds with a CTS IMMEDIATE ASSIGNMENT message on the CTS Access Grant Channel.
Mobile Station Fixed Part
CTS ACCESS REQUEST
───────────────────────────────────────>
CTS IMMEDIATE ASSIGNMENT
<───────────────────────────────────────
Figure 7.2/GSM 04.56: CTS immediate assignment
7.1.3 CTS mutual authentication
The purpose of CTS mutual authentication procedure is to validate the identity provided by the mobile station and the one provided by the fixed part. It is initiated by the fixed part. The CTS mutual authentication procedure also provides the mobile station with information from which a new ciphering key can be derived. The fixed part shall use the CTS mutual authentication at the beginning of each MM connection establishment (see GSM 03.20 annex E).
Mobile Station Fixed Part
CTS MS AUTHENTICATION REQUEST
<───────────────────────────────────────
CTS MS AUTHENTICATION RESPONSE
───────────────────────────────────────>
CTS FP AUTHENTICATION RESPONSE
<───────────────────────────────────────
Figure 7.3/GSM 04.56: CTS mutual authentication
7.2 Abnormal cases
Abnormal cases are not described in the examples of clause 7.
7.3 Selected examples
The following examples are considered:
– enrolment;
– attachment;
– detachment;
– de-enrolment;
– mobile originating call establishment.
7.3.1 Enrolment
The enrolment procedure is always initiated by the mobile station.
7.3.1.1 Enrolment with CTS-MS identity authentication done only by the CTS-FP
Mobile Station Fixed Part
+── ──+
│ CTS ACCESS REQUEST \ RR connection
\ ───────────────────────────────────────> │ establishment
│ CTS IMMEDIATE ASSIGNMENT │ (MO)
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS ENROLMENT REQUEST │
│ ───────────────────────────────────────> │ Service request
│ │
+── ──+
+── ──+
│ CTS MS AUTHENTICATION REQUEST │ Mutual
│ <─────────────────────────────────────── │ authentication
│ CTS MS AUTHENTICATION RESPONSE │
│ ───────────────────────────────────────> │
│ CTS FP AUTHENTICATION RESPONSE │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CIPHERING MODE COMMAND │ Ciphering
│ <─────────────────────────────────────── │ mode setting
│ CTS CIPHERING MODE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ IDENTITY REQUEST │ MS identity
│ <─────────────────────────────────────── │
│ IDENTITY RESPONSE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS ENROLMENT ACCEPT │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CHANNEL RELEASE │
│ <─────────────────────────────────────── │
+── ──+
Figure 7.4/GSM 04.56: CTS enrolment
7.3.1.2 Enrolment with CTS MS authentication done by CTS operator
Mobile Station Fixed Part
+── ──+
│ CTS ACCESS REQUEST │ RR connection
│ ───────────────────────────────────────> │ establishment
│ CTS IMMEDIATE ASSIGNMENT │ (MO)
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS ENROLMENT REQUEST │
│ ───────────────────────────────────────> │ Service request
│ │
+── ──+
+── ──+
│ CTS MS AUTHENTICATION REQUEST │ Mutual
│ <─────────────────────────────────────── │ authentication
│ CTS MS AUTHENTICATION RESPONSE │
│ ───────────────────────────────────────> │
│ CTS FP AUTHENTICATION RESPONSE │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CIPHERING MODE COMMAND │ Ciphering
│ <─────────────────────────────────────── │ mode setting
│ CTS CIPHERING MODE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ IDENTITY REQUEST │ MS identity
│ <─────────────────────────────────────── │
│ IDENTITY RESPONSE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ AUTHENTICATION REQUEST │
│ <─────────────────────────────────────── │ Authentication
│ AUTHENTICATION RESPONSE │ with CTS-SN
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS ENROLMENT ACCEPT │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CHANNEL RELEASE │
│ <─────────────────────────────────────── │
+── ──+
Figure 7.5/GSM 04.56: CTS enrolment
7.3.2 Attachment
The attachment procedure is always initiated by the mobile station.
Mobile Station Fixed Part
+── ──+
│ CTS ACCESS REQUEST │ RR connection
│ ───────────────────────────────────────> │ establishment
│ CTS IMMEDIATE ASSIGNMENT │ (MO)
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS ATTACH REQUEST │
│ ───────────────────────────────────────> │ Service request
│ │
+── ──+
+── ──+
│ CTS MS AUTHENTICATION REQUEST │ Mutual
│ <─────────────────────────────────────── │ authentication
│ CTS MS AUTHENTICATION RESPONSE │
│ ───────────────────────────────────────> │
│ CTS FP AUTHENTICATION RESPONSE │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CIPHERING MODE COMMAND │ Ciphering
│ <─────────────────────────────────────── │ mode setting
│ CTS CIPHERING MODE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS MSI UPDATE COMMAND │ CTSMSI updating
│ <─────────────────────────────────────── │
│ CTS MSI UPDATE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS ATTACH ACCEPT │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CHANNEL RELEASE │
│ <─────────────────────────────────────── │
+── ──+
Figure 7.6/GSM 04.56: CTS attachment
7.3.3 Detachment
The detachment procedure is always initiated by the mobile station.
Mobile Station Fixed Part
+── ──+
│ CTS ACCESS REQUEST │ RR connection
│ ───────────────────────────────────────> │ establishment
│ CTS IMMEDIATE ASSIGNMENT │ (MO)
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS DETACH INDICATION │
│ ───────────────────────────────────────> │ Service request
│ │
+── ──+
+── ──+
│ CTS CHANNEL RELEASE │
│ <─────────────────────────────────────── │
+── ──+
Figure 7.7/GSM 04.56: CTS detachment
7.3.4 De-enrolment
The de-enrolment procedure is always initiated by the fixed part.
Mobile Station Fixed Part
+── ──+
│ CTS PAGING REQUEST │ RR connection
│ <─────────────────────────────────────── │ establishment
│ CTS ACCESS REQUEST │ (MT)
│ ───────────────────────────────────────> │
│ CTS IMMEDIATE ASSIGNMENT │
│ <─────────────────────────────────────── │
│ CTS PAGING RESPONSE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS MS AUTHENTICATION REQUEST │ Mutual
│ <─────────────────────────────────────── │ authentication
│ CTS MS AUTHENTICATION RESPONSE │
│ ───────────────────────────────────────> │
│ CTS FP AUTHENTICATION RESPONSE │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CIPHERING MODE COMMAND │ Ciphering
│ <─────────────────────────────────────── │ mode setting
│ CTS CIPHERING MODE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS DE-ENROLMENT INDICATION │ De-enrolment
│ <─────────────────────────────────────── │ indication
+── ──+
+── ──+
│ CTS CHANNEL RELEASE │
│ <─────────────────────────────────────── │
+── ──+
Figure 7.8/GSM 04.56: CTS de-enrolment
7.3.5 Mobile originating call establishment
The mobile station initiates immediate assignment, service request using the CM SERVICE REQUEST message, and contention resolution.
Mobile Station Fixed Part
+── ──+
│ CTS ACCESS REQUEST │ RR connection
│ ───────────────────────────────────────> │ establishment
│ CTS IMMEDIATE ASSIGNMENT │ (MO)
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CM SERVICE REQUEST │
│ ───────────────────────────────────────> │ Service request
│ │
+── ──+
+── ──+
│ CTS MS AUTHENTICATION REQUEST │ Mutual
│ <─────────────────────────────────────── │ authentication
│ CTS MS AUTHENTICATION RESPONSE │
│ ───────────────────────────────────────> │
│ CTS FP AUTHENTICATION RESPONSE │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CTS CIPHERING MODE COMMAND │ Ciphering
│ <─────────────────────────────────────── │ mode setting
│ CTS CIPHERING MODE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ CTS MSI UPDATE COMMAND │ CTSMSI updating
│ <─────────────────────────────────────── │
│ CTS MSI UPDATE COMPLETE │
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ SET UP │
│ ───────────────────────────────────────> │ Call initiation
│ CALL PROCEEDING │
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ │
│ <─────────────────────────────────────── │ Channel
│ │ Assignment
│ ───────────────────────────────────────> │
+── ──+
+── ──+
│ ALERTING │ User alerting
│ <─────────────────────────────────────── │
+── ──+
+── ──+
│ CONNECT │
│ <─────────────────────────────────────── │ Call accepted
│ CONNECT ACKNOWLEDGE │
│ ───────────────────────────────────────> │
+── ──+
Figure 7.9/GSM 04.56: Mobile originating call establishment