Dialling, Numbering & Addressing

Pieter de Kruyff

R&S BICK Mobilfunk GmbH

Agenda

• Definition of terms

• Dialling & Man Machine Interface (MMI)

• Addresses and Identities

• Numbering and Addressing

• Call Scenarios

Definition of terms(as used in this presentation)

DIALLING - Identity exchange mechanism between User and Terminal

NUMBERING - decimal representation of air-interface addresses as seen by the user i.e. user visible numbering

ADDRESSING - Identity exchange mechanism over air- interface, provides the routing information for the network

TETRA Dialling & MMI

Man-Machine Interface MMI - ETR 294

Full dialling

Mode keys

Soft keys

Display scrolling

Number presentation (CLI & TPI)

Special numbers e.g. 999/ 112

ETSI doc. TR 102 300-5: Leading Digit dialling Relative and Shortened dialling

ID exchange between user and terminal

TETRA Identity

MOBILE NETWORK ID SHORT SUBSCRIBER ID

SHORT SUBSCRIBER IDENTITY

(SSI)

MOBILECOUNTRY

CODE(MCC)

MOBILE NETWORK

CODE(MNC)

24 BINARY BITS7/8 DECIMAL DIGITS

10 BITS3/4 DIGITS

14 BITS4/5 DIGITS

24 BINARY BITS 24 BINARY BITS

Family of TETRA Addresses

(ITSI) INDIVIDUAL TETRA SUBSCRIBER IDENTITY

(ATSI) ALIAS TETRA SUBSCRIBER IDENTITY

(GTSIs) GROUP TETRA SUBSCRIBER IDENTITIES

HOME NETWORK

(V)ATSI VISITING ALIAS TETRA SUBSCRIBER IDENTITY

(V)GTSIs VISITING GROUP TETRA SUBSCRIBER IDENTITIES

VISITING NETWORK

How many numbers for a TETRA Terminal?• One Family of Home Network TSIs

– One Individual TETRA Number ITSI– One Alias of individual Number ATSI– One or more TETRA Group Numbers GTSIs

• One or more Families of Visiting Network TSIs – Unassigned SSI (USSI)– One Visiting Alias (V)ATSI– One or more Visiting Group Numbers (V)GTSIs

• One telephone number (E.164)

Numbering & Addressing

• Numbering and Addressing Plans• Basic Numbering• Enhanced Numbering• Leading Digit Dialling• Call Scenarios

– Home & Foreign Network– PABX & E.164

Linking TETRA Addressing & Numbering

SHORT SUBSCRIBER IDENTITY

(SSI)

MOBILECOUNTRY

CODE(MCC)

MOBILE NETWORK

CODE(MNC)

3/4 DIGITS 4/5 DIGITS 7 / 8 DECIMAL DIGITS

TETRA ADDRESSTETRA ADDRESS

TETRA NUMBERTETRA NUMBER

Basic TETRA Number SSI

• Communication within home TETRA Network

• No need for algorithm selection• Home dialling algorithm applies

– decimal value range from 0 to 16,777,215 (224)– User may dial between 1 and 8 digits – 7 digit with max value 9 999 999 recommended

• Decimal digits are converted to binary SSI

Enhanced TETRA Numbering

• Communication beyond home TETRA Network e.g. another TETRA, PABX, PSTN, ISDN

• Need for algorithm selection• Selection of Dialling Plan

– Direct number entry via keypad, Mode selection buttons, Soft key menu selection, Leading Digit Dialling

• DTMF can be used to access services outside TETRA networks during a call.

Leading Digit Dialling

• Leading Digit Dialling is the only dialling algorithm selection defined in TR 102 300-5

• Recommended way to achieve commonality between manufacturers’ implementations– Predefined value for E.164 gateway access

is 16,777,184– Predefined value for ISDN gateway access

is 16,777,185– 14 more values reserved for future use.

Dialling methods

• Relative dialling

• Shortened dialling

The last digits of the own SSI are replaced with the dialled digits to form the identity of the subscriber to be called

The last digits of a predefined base address (SSI) are replaced with the dialled digits to form the identity of the subscriber to be called

Private Numbering Plans• A private numbering plan uses a number space which is

independent of TETRA SSI or E.164 numbering.

• The TETRA MoU has prepared two specifications for private numbering:

• Fleet Specific Short Number (FSSN, TTR001- 7)

• Radio User Number (RUN, TTR001 - 18)

• The TETRA Standard describes Short Number Addressing (SS-SNA, ETS 300 392-10-7), which provides a private numbering space of 256 addresses.

Fleet Specific Short Number• FSSN uses one million addresses from the SSI addressing

space with a base address of 15.000.000. The calling user may dial the FSSN of up to 6 digits, which are added to the base address.

• The Air Interface provides the transposed number (15.nnn.nnn) to the infrastructure where the number is translated to the real SSI of the called subscriber.

• The calling subscribers identity is translated to the associated FSSN number and presented as CLI at the called terminal.

• The FSSN numbering space may be re-used by several user organisations.

Radio User Number• The RUN identifies the user rather than the radio terminal.

When the user authenticates himself (RUA, TTR001-17), part of the process is entering his RUN, which is mapped by the system to the ITSI of the used radio terminal.

• The infrastructure resolves the called ITSI from the called RUN for the routing of the call as well as the calling RUN from the calling ITSI for display as the CLI at the called terminal.

• The call setup message is addressed to the SSI identifying the RUN application. The RUN is carried in the ESN field in the same way as an E.164 number.

Call Scenarios

• Call originating and terminating on same Network,

• Call originating and terminating on different Networks

• Calls between TETRA and PABX

• Calls between TETRA and E.164 (PSTN, GSM, TETRA!)

Scenario 1- Home Network

TETRATETRA

9 2

MNCMNCMCCMCC SSISSI

1

MNCMNCMCCMCC SSISSI

1 2 3 4 5 6 7

1 2 3 4 5 6

Calling Subscriber

Scenario 2 - Foreign TETRA Net

TETRA (UK)TETRA (UK)

TETRA (UK)TETRA (UK)

TETRA (France)TETRA (France)MCCMCC MNCMNC SSISSI

MCCMCC MNCMNC SSISSI

ISIISI

ISI

PABX GWMNI

PABX GWSSI

PABX Subscriber Number (24 digits)

Scenario 3 - PABX

TETRA (A)TETRA (A) TETRA (B )TETRA (B )ISIPABXGW

PABX (A)

PABXGW

PABX (B)

Scenario 4 - E.164 (PSTN, GSM)

E.164 GWMNI

E.164 GWSSI

External Subscriber Number (24 digits)

E.164 GWMNI

E.164 GWSSI

E.164 Subscriber Number (24 digits)

TETRA (UK)TETRA (UK) TETRA (Germany)TETRA (Germany)

E.164 (PSTN, GSM)E.164 (PSTN, GSM)

ISI

E.164GW

E.164GW

UK Phone German Phone

TETRA IP

• TETRA uses IP numbers in the same way as any other IP network

• Individual TETRA user can have a fixed IP number or the number can be allocated dynamically

• In order to do the air interface signalling, TETRA IP numbers need to be mapped to TETRA ITSIs

Conclusions• TETRA dialling plans TETRA dialling plans provide the

benefits of flexibility and interoperability to meet the huge variety of needs of professional users

• TETRA numbering plans TETRA numbering plans have flexibility to efficiently deal both with simple fleet numbers & full E.164 international numbers

• TETRA addressingTETRA addressing alignment allows for future interoperability/ roaming with GSM