Each CTS-MS has one or more temporary identities which are used for paging and to request access. The structure and allocation principles of the CTS Mobile Subscriber Identities (CTSMSI) are defined below.

The CTSMSI is composed of the following elements:

• CTSMSI Type. Its length is 2 bits;
• Significant Part. Its length is 20 bits.

The following CTSMSI Type values have been allocated for use by CTS:

The default Individual CTSMSI contains the least significant portion of the IMSI. This is the default CTS-MS identity. Assigned CTSMSIs are allocated by the CTS-FP during enrolment, registration and other access procedures. Significant Part of the assigned CTSMSI shall be allocated in the range 00001-FFFFE. CTS-FP shall not allocate Significant Part equal to 00000 or to FFFFF and shall not allocate Assigned CTSMSI using Reserved Type value. Such assignments shall be ignored by the CTS-MS. Assigned CTSMSIs are allocated in ciphered mode. The value FFFFF from the set of Assigned Connectionless Group CTSMSI shall be considered in all CTS-MS as the value of the Connectionless Broadcast Identifier.

The 22 bits of CTSMSI are padded with 2 leading zeroes to give a 6 digit hexadecimal value. EXAMPLE:

Each CTS-FP has one Fixed Part Beacon Identity known by the enrolled CTS-MSs. The FPBI is periodically broadcast on the BCH logical channel so that the CTS-MSs are able to recognise the identity of the CTS-FP. The FPBI contains an Access Rights Identity. Enrolled CTS-MSs shall store the FPBI to which their assigned CTSMSIs are related. Below the structure and allocation principles of the Fixed Part Beacon Identity (FPBI) are defined.

The FPBI shall be allocated during the CTS-FP initialisation procedure. Any change to the value of the FPBI of a given CTS-FP shall be considered as a CTS-FP re-initialisation; i.e. each enrolled CTS-MS needs to be enrolled again. FPBI are not required to be unique (i.e. several CTS-FP can have the same FPBI in different areas). Care should be taken to limit CTS-MS registration attempts to a fixed part with the same FPBI as another fixed part.

The structure and allocation principles of the International Fixed Part Equipment Identity (IFPEI) are defined below.

The IFPEI is composed of the following elements (each element shall consist of decimal digits only):

• Type Approval Code (TAC). Its length is 6 decimal digits;
• Final Assembly Code (FAC). Its length is 2 decimal digits;
• Serial NumbeR (SNR). Its length is 6 decimal digits;
• Software Version Number (SVN) identifies the software version number of the fixed part equipment. Its length is 2 digits.

Regarding updates of the IFPEI: the TAC, FAC and SNR shall be physically protected against unauthorised change (see TS 42.009); i.e. only the SVN part of the IFPEI can be modified.

The Type Approval Code (TAC) is issued by a global administrator. The place of final assembly (FAC) is encoded by the manufacturer. Manufacturers shall allocate unique serial numbers (SNR) in a sequential order. The Software Version Number (SVN) is allocated by the manufacturer after authorisation by the type approval authority. SVN value 99 is reserved for future use.

The structure and allocation principles of the International Fixed Part Subscription Identity (IFPSI) are defined below.

The IFPSI is composed of the following elements (each element shall consist of decimal digits only):

• Mobile Country Code (MCC) consisting of three digits. The MCC identifies the country of the CTS-FP subscriber (e.g. 208 for France);
• CTS Operator Number (CON). Its length is three digits;
• Fixed Part Identification Number (FPIN) identifying the CTS-FP subscriber.

The National Fixed Part Subscriber Identity (NFPSI) consists of the CTS Operator Number and the Fixed Part Identification Number.

IFPSI shall consist of decimal characters (0 to 9) only. The allocation of Mobile Country Codes (MCCs) is administered by the ITU. The allocation of CTS Operator Number (CON) and the structure of National Fixed Part Subscriber Identity (NFPSI) may be responsibility of each national numbering plan administrator. CTS Operators shall allocate unique Fixed Part Identification Numbers.