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marked/Q/T-REC-Q.101-198811-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with latitude and longitude lines. A lightning bolt symbol is positioned to the right of the globe.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+**Q.101**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**GENERAL RECOMMENDATIONS ON TELEPHONE  
+SWITCHING AND SIGNALLING**
+
+**CLAUSES APPLICABLE TO ITU-T STANDARD  
+SYSTEMS**
+
+---
+
+**FACILITIES PROVIDED IN INTERNATIONAL  
+SEMI-AUTOMATIC WORKING**
+
+**ITU-T Recommendation Q.101**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation Q.101 was published in Fascicle VI.1 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## **1.1 FACILITIES PROVIDED IN INTERNATIONAL SEMI-AUTOMATIC WORKING**
+
+1.1.1 The operating methods used in the semi-automatic international service are described in the *Instructions for the International Telephone Service*. These operating methods assume the existence of equipment (operator's positions and automatic switching equipment) involving the following categories of operators:
+
+- a) *outgoing* operators;
+- b) *incoming* operators;
+- c) *delay* operators;
+- d) *assistance* operators;
+- e) *information* or *special service* operators.
+
+1.1.2 The *outgoing operator* controls the setting up of calls at the outgoing exchange. (From the operating point of view she is, in general, the controlling operator and is sometimes so referred to in the *Instructions*.)
+
+She must be able to set up calls to any one of the following points in the called country:
+
+- a) subscribers;
+- b) incoming operators at the incoming international exchange;
+- c) delay operators, especially a particular delay operator at the incoming international exchange;
+- d) incoming operators at a local manual exchange in the called country;
+- e) information or special service operators.
+
+The outgoing operator should be able to recall incoming and delay operators on calls set up via these operators, by sending a forward-transfer signal as defined in the relevant system specifications.
+
+1.1.3 The *incoming operator*<sup>1)</sup> at the incoming international exchange is obtained by using a special code 11 signal or a special number. The code 11 signal is a particular combination provided by the signal code. This operator performs the functions of an incoming operator in ordinary manual service for those calls which cannot be routed automatically at the incoming international exchange.
+
+1.1.4 The *delay operator* is obtained by using a special code 12 signal, or a special number. The code 12 signal is a particular combination provided by the signal code. The delay operator may be:
+
+- any of the operators of this category;
+- or a particular operator, or one of those operating a particular group of positions; her position or her group of positions is then indicated by a number which follows the code 12 signal or is indicated by the special number.
+
+With respect to the direction in which a required call is set up, the delay operator may be at the outgoing international exchange and may be called by an operator at the incoming international exchange. From the technical point of view and as far as signalling is concerned, however, the delay operator at the outgoing international exchange called back by an operator at an incoming international exchange must be regarded as being at the incoming end of the international circuit over which she has been called back.
+
+1.1.5 *Notes on incoming and delay operators*
+
+a) Incoming and delay operators must be able to speak the *service language* used for the route concerned, and hence may have to belong to a particular language group. A *language (or information) digit*, from 1 to 8, sent on all
+
+---
+
+<sup>1)</sup> Called alternatively in French "opératrice translatrice", see *Instructions for the International Telephone Service* (art. 125).
+
+semi-automatic calls, is used to obtain operators of a particular language group [see Recommendation Q.104]<sup>2)</sup>.
+
+- b) It may be the same operator who acts as an incoming and as a delay operator, and even as an assistance operator. She enters a circuit in any of these capacities in response to the appropriate signal.
+- c) While an incoming or delay operator is being called, the national ringing tone of the incoming country must be sent back over the international circuit.
+
+1.1.6 The *assistance operator* at the incoming international exchange enters a semi-automatic circuit on a call already set up, when requested by the outgoing operator, because of language difficulties or, for instance, when she is required to interpret a national tone. Access to an assistance operator at an international transit exchange is not possible.
+
+The assistance operator is called by a forward-transfer signal, sent by the outgoing operator when, for example, she operates a key on the outgoing position. An assistance operator in a required language group is obtained in conjunction with the forward-transfer signal by the language digit (or information) sent previously during the setting up of the call. Hence the incoming relay set must store the language digit (or information).
+
+The outgoing operator receives no indication to show that the assistance operator is being called, or to show when she answers or withdraws from the circuit, but if necessary the outgoing operator can send the forward-transfer signal several times on the same call.
+
+The assistance operator must be able:
+
+- a) to break into the call as a third party (this she would do, for example, when the language spoken in the country of arrival is other than the service language used in that relation, and the operator intervenes as an interpreter);
+- b) to enter a circuit on one side only after having isolated the other. She does this, in particular, when she translates a verbal announcement or interprets an audible tone returned from the incoming end.
+
+In no circumstances will the assistance operator be able to block the international circuit.
+
+*Note* - It should be noted that the term "assistance operator" has a very definite meaning in CCITT documents. It stands for an operator who breaks in, as required, as a third party in a circuit already set up. Hence this operator must not be confused with any other operator in the incoming country who may help to *set up* the call in conjunction with the international outgoing operator. Assistance operators may not be available on intraregional circuits.
+
+1.1.7 The *information or special service operator* of the country of destination is obtained by using a special number. This operator is responsible for giving details concerning subscriber number and miscellaneous inquiries.
+
+---
+
+2) The language digit may not be used on some intraregional circuits.

marked/Q/T-REC-Q.106-198811-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with latitude and longitude lines. A lightning bolt symbol is positioned to the right of the globe.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+**Q.106**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**GENERAL RECOMMENDATIONS ON TELEPHONE  
+SWITCHING AND SIGNALLING**
+
+**CLAUSES APPLICABLE TO ITU-T STANDARD  
+SYSTEMS**
+
+---
+
+**THE SENDING - FINISHED SIGNAL**
+
+**ITU-T Recommendation Q.106**
+
+(Extract from the *Blue Book*)
+
+---
+
+## NOTES
+
+1 ITU-T Recommendation Q.106 was published in Fascicle VI.1 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## **1.6 THE SENDING-FINISHED SIGNAL**
+
+In semi-automatic working, when the international outgoing operator has finished keying or dialling, she operates a special button on her keyboard or a key so that, after the number, a local signal which is called a *sending-finished* signal is sent to the outgoing equipment to show that there are no more digits to follow. In automatic working, subscribers cannot show when they have finished dialling the number, and so this signal does not apply.
+
+*Note* - In semi-automatic working, local sending of the sending-finished signal will cause an *end-of-pulsing* signal to be sent on the international circuit <sup>1)</sup> or signalling channel. This has the same function and shows the incoming equipment that there are no more digits to be received. In some cases also in automatic working, when the outgoing equipment decides that there are no more digits to follow, an end-of-pulsing signal is sent on the international circuit or signalling channel, for example in the ST condition of System No. 5 (see Recommendation Q.152).
+
+---
+
+<sup>1)</sup> In System R2 the sending of end-of-pulsing signal (code 15) may not occur if a *number-received* indication has already been received.

marked/Q/T-REC-Q.109-198811-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with latitude and longitude lines. A lightning bolt symbol is positioned to the right of the letters.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+**Q.109**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**GENERAL RECOMMENDATIONS ON TELEPHONE  
+SWITCHING AND SIGNALLING**
+
+**CLAUSES APPLICABLE TO ITU-T STANDARD  
+SYSTEMS**
+
+---
+
+**TRANSMISSION OF THE ANSWER SIGNAL IN  
+INTERNATIONAL EXCHANGES**
+
+**ITU-T Recommendation Q.109**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation Q.109 was published in Fascicle VI.1 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## **1.9 TRANSMISSION OF THE ANSWER SIGNAL IN INTERNATIONAL EXCHANGES**
+
+For the reasons given in Recommendation Q.27, it is necessary to reduce to a minimum the delays resulting from:
+
+- the conversion of the national answer signal into the international answer signal and vice versa; and
+- the transmission of the international answer signal over the international part of the connection,
+
+these delays being additional to any delays due to conversions and repetitions of the answer signal within the national systems of the incoming and outgoing countries.

marked/Q/T-REC-Q.113-198811-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with latitude and longitude lines.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+**Q.113**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**GENERAL RECOMMENDATIONS ON TELEPHONE  
+SWITCHING AND SIGNALLING**
+
+**CLAUSES APPLICABLE TO ITU-T STANDARD  
+SYSTEMS**
+
+---
+
+**CONNECTION OF SIGNAL RECEIVERS IN  
+THE CIRCUIT**
+
+**ITU-T Recommendation Q.113**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation Q.113 was published in Fascicle VI.1 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## **2.2 CONNECTION OF SIGNAL RECEIVERS IN THE CIRCUIT**
+
+2.2.1 The line signal receivers are permanently connected to the 4-wire side of the circuit. The register signal receivers in System No. 5 are connected to the 4-wire side of the circuit when the register is associated with the circuit for the setting up of the call; the same is valid (in the international exchanges) for the register signal receivers in Systems R1 and R2.
+
+2.2.2 An in-band line signal receiver should be protected against disturbing currents (voice currents or possibly noise), coming from the near end of the circuit, by a buffer amplifier or other arrangement. The arrangement used should introduce an appropriate supplementary attenuation in such a manner that, at the point where the line signal receiver is connected, these disturbing currents are of such a level that they cannot:
+
+- operate the line signal receiver;
+- interfere with the reception of signals by operating the guard circuit of the line signal receiver.
+
+The additional attenuation introduced should in consequence take account of:
+
+- a) the relative level  $n$  at the point where the signal receiver is connected (this relative level is obtained by assuming a zero relative level at the distant origin of the circuit);
+- b) the minimum permissible signal level at the input to the signal receiver, for example:
+  - $-18 + n$  dBm in the case of System No. 4 (see Recommendation Q.123 § 3.2.1),
+  - $-16 + n$  dBm in the case of System No. 5 (see Recommendation Q. 144 § 2.4.1);
+- c) the maximum permissible level for disturbing currents (voice currents and switching noise) coming from the near end of the circuit. The maximum level of voice current might be assumed to be, for example,  $+10$  dBm0 in the direction *opposite* to that of the signals. The nature of the switching noises depends on the national systems used;
+- d) any attenuation (terminating set and possibly pads) between the point where the signal receiver is connected and the point where the near-end disturbing currents are considered;
+- e) a safety margin to give an appreciable reduction of the level of disturbing currents coming from the near end [as defined in c)] compared to the minimum level of the signal as defined in b).
+
+2.2.3 When a register-signal receiver is connected to the circuit, the exchange side of the circuit is disconnected and hence the receiver is not subject to near-end disturbances.
+
+2.2.4 The Recommendations of Volume III concerning international circuits must still be met after the connection of a signal sender and a signal receiver and of the switching equipment. In consequence, it is necessary to fix the limits of input and output impedance, insertion loss, attenuation distortion, non-linear distortion, balance, and crosstalk of line signal senders and receivers; an example of specification clauses concerning these conditions is given in Recommendation Q.114.

marked/Q/T-REC-Q.114-198811-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+**Q.114**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**GENERAL RECOMMENDATIONS ON TELEPHONE  
+SWITCHING AND SIGNALLING**
+
+**CLAUSES APPLICABLE TO ITU-T STANDARD  
+SYSTEMS**
+
+---
+
+**TYPICAL TRANSMISSION REQUIREMENTS  
+FOR SIGNAL SENDERS AND RECEIVERS**
+
+**ITU-T Recommendation Q.114**
+
+(Extract from the *Blue Book*)
+
+---
+
+# NOTES
+
+1 ITU-T Recommendation Q.114 was published in Fascicle VI.1 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below).
+
+2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## 2.3 TYPICAL TRANSMISSION REQUIREMENTS FOR SIGNAL SENDERS AND RECEIVERS
+
+2.3.1 In-band line signal receivers (including the buffer amplifier or equivalent device), in §§ 2.3.2 to 2.3.7 below, apply only in the case where the signal receiver is a 4-terminal device ("quadrupole") and where the nominal circuit impedance is 600 ohms.
+
+### 2.3.2 *Input and output impedance*
+
+The nominal value of the input and output impedances of the signal receiver is 600 ohms.
+
+$Z_E$  and  $Z_S$ , which are respectively the measured values of the input and output impedance of the signal receiver, should meet the following condition throughout the 300 to 3400 Hz frequency band:
+
+$$\left| \frac{Z_E - 600}{Z_E + 600} \right| \leq 0.35 \text{ and } \left| \frac{Z_S - 600}{Z_S + 600} \right| \leq 0.35.$$
+
+In making these measurements the free terminals should be looped by a resistance of 600 ohms and the voltage applied must not overload the equipment.
+
+### 2.3.3 *Attenuation*
+
+At 800 Hz, the insertion loss of the signal receiver, measured with a generator and a receiver of internal resistance of 600 ohms, must be between the limits:
+
+$$A \pm 0.5 \text{ decibel}$$
+
+The value  $A$  is to be determined from the level diagram of the circuit according to the point of the circuit at which the signal receiver should be connected.
+
+The measurement is made with a 1 mW generator having an internal impedance equal to a pure resistance of 600 ohms and having an e.m.f. of  $2 \times 0.775$  volt (so-called "standard generator"). The e.m.f. of the generator will be adjusted to take into account the relative level of the point of the circuit at which the signal receiver is connected.
+
+If  $n$  is the relative level at the signal receiver input, the e.m.f. of the generator will therefore be:
+
+$$1.55 \cdot 10^{\frac{n}{20}} \text{ volts, if } n \text{ is expressed in decibels.}$$
+
+### 2.3.4 *Attenuation distortion*
+
+The variation in insertion loss of the signal receiver in the 300-3400 Hz frequency band, measured under the conditions of § 2.3.3 above, should not exceed the limits shown in Figure 1/Q.114.
+
+As in certain cases Systems No. 5, and R1 may be applied to circuits in transmission systems with a channel spacing of less than 4 kHz, the 300 Hz lower limit shown above may be replaced by 200 Hz for System No. 5.
+
+### 2.3.5 *Nonlinear distortion*
+
+The curve representing the variation (as a function of power) of the output level of the signal receiver, with reference to the nominal value of the output level, should be within the limits shown in Figure 2/Q.114 over the relevant frequency range.
+
+### 2.3.6 *Balance*
+
+The input and output of the signal receiver should have a high degree of balance to earth, the admittance of each terminal to earth being very low.
+
+The same clause should apply to the signal sender.
+
+![Figure 1/Q.114: Attenuation distortion of the signal receiver. A graph showing attenuation in dB versus frequency in Hz. The y-axis ranges from -0.2 to +0.5 dB. The x-axis has markers at 300, 600, 800, 2400, and 3400 Hz. The graph shows a shaded region between +0.2 dB and +0.5 dB from 300 Hz to 2400 Hz, and another shaded region between -0.2 dB and +0.5 dB from 2400 Hz to 3400 Hz. The text 'CCITT - 48 501' is at the bottom right.](09af5b86cf9391543d22db5f2129b3ca_img.jpg)
+
+Figure 1/Q.114: Attenuation distortion of the signal receiver. A graph showing attenuation in dB versus frequency in Hz. The y-axis ranges from -0.2 to +0.5 dB. The x-axis has markers at 300, 600, 800, 2400, and 3400 Hz. The graph shows a shaded region between +0.2 dB and +0.5 dB from 300 Hz to 2400 Hz, and another shaded region between -0.2 dB and +0.5 dB from 2400 Hz to 3400 Hz. The text 'CCITT - 48 501' is at the bottom right.
+
+FIGURE 1/Q.114  
+Attenuation distortion of the signal receiver
+
+![Figure 2/Q.114: Limits for nonlinear distortion due to the insertion of the signal receiver. A graph showing the variation of the output level in dB versus the power level applied to the input in dBm0. The y-axis ranges from -0.2 to +0.2 dB. The x-axis has a marker at 3.5 dBm0. The graph shows a shaded region between -0.2 dB and +0.2 dB up to 3.5 dBm0. The text 'CCITT - 48 511' is at the bottom right. A note indicates: 'Power level applied to the input of the signal receiver and referred to zero relative level'.](a30a7877bf2f45b837a9382e22067ad0_img.jpg)
+
+Figure 2/Q.114: Limits for nonlinear distortion due to the insertion of the signal receiver. A graph showing the variation of the output level in dB versus the power level applied to the input in dBm0. The y-axis ranges from -0.2 to +0.2 dB. The x-axis has a marker at 3.5 dBm0. The graph shows a shaded region between -0.2 dB and +0.2 dB up to 3.5 dBm0. The text 'CCITT - 48 511' is at the bottom right. A note indicates: 'Power level applied to the input of the signal receiver and referred to zero relative level'.
+
+FIGURE 2/Q.114  
+Limits for nonlinear distortion due to the insertion of the signal receiver
+
+### 2.3.7 *Crosstalk between adjacent signal receivers*
+
+The crosstalk ratio between two adjacent signal receivers should not be less than 74 dB in the relevant frequency band.
+
+2.3.8 During the register signalling period no speech transmission takes place. It is not essential therefore for the register signalling equipment of systems having separate equipment for that purpose to take account of §§ 2.3.2 to 2.3.7 above but it is desirable to adopt appropriate clauses for efficient signalling performance.

marked/Q/T-REC-Q.1200-199709-I_PDF-E/raw.md

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**Q.1200**
+
+(09/97)
+
+SERIES Q: SWITCHING AND SIGNALLING
+
+Intelligent Network
+
+# --- **General series Intelligent Network Recommendation structure**
+
+ITU-T Recommendation Q.1200
+
+(Previously CCITT Recommendation)
+
+---
+
+# ITU-T Q-SERIES RECOMMENDATIONS
+
+## **SWITCHING AND SIGNALLING**
+
+|                                                          |                      |
+|----------------------------------------------------------|----------------------|
+| SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE           | Q.1-Q.3              |
+| INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING       | Q.4-Q.59             |
+| FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN | Q.60-Q.99            |
+| CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS             | Q.100-Q.119          |
+| SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5     | Q.120-Q.249          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 6                | Q.250-Q.309          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R1                   | Q.310-Q.399          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R2                   | Q.400-Q.499          |
+| DIGITAL EXCHANGES                                        | Q.500-Q.599          |
+| INTERWORKING OF SIGNALLING SYSTEMS                       | Q.600-Q.699          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 7                | Q.700-Q.849          |
+| DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1               | Q.850-Q.999          |
+| PUBLIC LAND MOBILE NETWORK                               | Q.1000-Q.1099        |
+| INTERWORKING WITH SATELLITE MOBILE SYSTEMS               | Q.1100-Q.1199        |
+| <b>INTELLIGENT NETWORK</b>                               | <b>Q.1200-Q.1999</b> |
+| BROADBAND ISDN                                           | Q.2000-Q.2999        |
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## **ITU-T RECOMMENDATION Q.1200**
+
+# **GENERAL SERIES INTELLIGENT NETWORK RECOMMENDATION STRUCTURE**
+
+## **Summary**
+
+This Recommendation explains the structure of the Q.1200-series Intelligent Network (IN) Recommendations and provides the outline of all general (i.e. Q.120x-series) Recommendations.
+
+## **Source**
+
+ITU-T Recommendation Q.1200 was revised by ITU-T Study Group 11 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 12th of September 1997.
+
+# FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+# NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+# INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1999
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+# CONTENTS
+
+*Page*
+
+|   |                                                           |   |
+|---|-----------------------------------------------------------|---|
+| 0 | Introduction .....                                        | 1 |
+| 1 | General structure .....                                   | 1 |
+| 2 | Q-series Intelligent Network Recommendation overview..... | 1 |
+
+
+
+# **GENERAL SERIES INTELLIGENT NETWORK RECOMMENDATION STRUCTURE**
+
+*(revised in 1997)*
+
+# **0 Introduction**
+
+A block of one hundred numbers has been set aside in the Q series for the development of Intelligent Network (IN) Recommendations. This Recommendation, the first in that series, has been developed to organize the Recommendations in a meaningful way in order to assist users in locating topics of interest. It defines the structure of the Q.1200-series Recommendations and assigns blocks of numbers to the groupings of IN capabilities known as Capability Sets (CSs) and blocks of numbers for general and vocabulary sections. In addition, this Recommendation provides a structural overview of the content of each Recommendation.
+
+This Recommendation has been developed with a long range view in mind. By assigning blocks of numbers to each capability set (CS-1, CS-2, CS-n), an organized, parallel structure across capability sets can be maintained; for example, CS-1 has been assigned the Q.121x block of numbers and CS-2 the Q.122x block of numbers.
+
+Associated work has been documented in the I-series Recommendations. For the sake of consistency, Recommendations Q.1201, Q.1202 and Q.1203 have been assigned numbers in the I-series Recommendations (I.312, I.328 and I.329, respectively).
+
+## **1 General structure**
+
+Table 1 shows the overall Q.1200-series Intelligent Network Recommendation structural distribution through the "ten" digits (1201, 1211, 1221, etc.) and the "one" digits (i.e. 1201, 1211, 1221, etc.).
+
+**Table 1/Q.1200 – Recommendation framework structure**
+
+|                                                                             |                                           |
+|-----------------------------------------------------------------------------|-------------------------------------------|
+| 00 – General                                                                |                                           |
+| 10 – CS-1                                                                   | 1 – Principles introduction               |
+| 20 – CS-2                                                                   | 2 – Service plane (not included for CS-1) |
+| 30 – CS-3                                                                   | 3 – Global functional plane               |
+| 40 – CS-4                                                                   | 4 – Distributed functional plane          |
+| 50 – CS-5                                                                   | 5 – Physical plane                        |
+| 60 – CS-6                                                                   | 6 – For future use                        |
+| 70 – CS-7                                                                   | 7 – For future use                        |
+| 80 – CS-8                                                                   | 8 – Interface Recommendation              |
+| 90 – Glossary                                                               | 9 – Intelligent Network user's guide      |
+| NOTE 1 – 1200 is assigned as for the IN Recommendation framework structure. |                                           |
+| NOTE 2 – 1290-series has been set aside for the glossary.                   |                                           |
+
+## **2 Q-series Intelligent Network Recommendation overview**
+
+### **Q.1200 – General series Intelligent Network Recommendation structure**
+
+- 0 Introduction
+- 1 General structure
+- 2 Q-series Intelligent Network Recommendation overview
+
+### **I.312/Q.1201 – Principles of Intelligent Network architecture**
+
+- 1 Objectives, overall description
+  - 1.1 Motivation, objectives, scope of Intelligent Network
+    - 1.1.1 Motivation
+    - 1.1.2 Objectives of Intelligent Network
+    - 1.1.3 Scope of Intelligent Network
+  - 1.2 Definition of Intelligent Network
+  - 1.3 Evolution of Intelligent Network Recommendations
+    - 1.3.1 General considerations on the standardization process
+    - 1.3.2 Recommendation areas
+    - 1.3.3 Phased standardization and definition of capability sets
+- 2 IN functional requirements
+  - 2.0 Introduction
+  - 2.1 Service requirements
+    - 2.1.1 Overall requirements
+    - 2.1.2 Service creation
+    - 2.1.3 Service management
+    - 2.1.4 Service processing
+    - 2.1.5 Service interworking
+  - 2.2 Network requirements
+    - 2.2.1 Overall requirements
+    - 2.2.2 Service creation
+    - 2.2.3 Service management
+    - 2.2.4 Network management
+    - 2.2.5 Service processing
+    - 2.2.6 Network interworking
+- 3 IN architectural concept
+  - 3.1 IN Conceptual Model (INCM)
+    - 3.1.1 Service plane
+    - 3.1.2 Global functional plane
+    - 3.1.3 Distributed functional plane
+    - 3.1.4 Physical plane
+    - 3.1.5 Relationship with the 3-stage method
+    - 3.1.6 Service logic
+    - 3.1.7 Application Programming Interface (API)
+    - 3.1.8 Relationships among different planes
+    - 3.1.9 Service interaction
+    - 3.1.10 Service and network interworking
+    - 3.1.11 Management functionality
+- 4 Intelligent Network (IN) long-term architecture framework
+  - 4.1 Introduction
+  - 4.2 Intelligent Network Conceptual Model
+  - 4.3 Architecture structure
+    - 4.3.1 Logical architecture
+    - 4.3.2 Physical architecture
+    - 4.3.3 Open distributed processing view
+  - 4.4 Service considerations
+    - 4.4.1 Service/service feature interaction
+  - 4.5 Technology basis
+    - 4.5.1 Broadband capabilities
+    - 4.5.2 Distributed processing
+    - 4.5.3 Open Systems Interconnection (OSI)
+    - 4.5.4 Object-oriented modelling
+    - 4.5.5 Information technology
+    - 4.5.6 Cooperative processing
+    - 4.5.7 Distributed control
+    - 4.5.8 Management of services and networks
+    - 4.5.9 Verification/validation
+    - 4.5.10 Artificial intelligence
+
+### **I.328/Q.1202 – Intelligent Network Service plane architecture**
+
+- 1 General
+- 2 Service plane architecture
+  - 2.0 General
+  - 2.1 Characterization of services and service capability requirements
+  - 2.2 Service plane modelling
+  - 2.3 Service and service feature interaction
+    - 2.3.1 The service and feature interaction problem
+    - 2.3.2 A solution: Which one?
+    - 2.3.3 A solution: When?
+    - 2.3.4 A solution: How?
+
+Annex A – Alphabetical list of abbreviations used in this Recommendation
+
+Annex B – A thesaurus of examples
+
+- B.1 General
+- B.2 Call Forwarding Unconditional and Terminating Key Code Screening
+  - B.2.1 First case
+  - B.2.2 Second case
+- B.3 Call Forwarding Unconditional and Automatic Call Back
+  - B.3.1 First case
+  - B.3.2 Second case
+- B.4 Call Forwarding Unconditional and Terminating Call Screening
+
+### **I.329/Q.1203 – Intelligent Network global functional plane architecture**
+
+- 1 General
+- 2 Scope of IN global functional plane architecture
+- 3 References
+- 4 Global functional plane modelling
+- 5 Service independent building blocks
+  - 5.1 Definition of an SIB
+  - 5.2 Characteristics of an SIB
+  - 5.3 Data parameters for SIBs
+  - 5.4 Method to describe SIBs
+  - 5.5 Flowchart analysis
+  - 5.6 Interaction management
+    - 5.6.1 Interaction between SIBs
+- 6 Basic call process
+  - 6.1 General
+  - 6.2 Basic call process functionality
+- 7 Global service logic
+  - 7.1 General
+
+Annex A – Alphabetical list of abbreviations used in this Recommendation
+
+### **Q.1204 – Intelligent Network distributed functional plane architecture**
+
+- 1 General
+- 2 Distributed functional plane model
+  - 2.1 Explanation of diagram
+    - 2.1.1 Functional entities
+    - 2.1.2 Relationships
+  - 2.3 Definition of functional entities related to IN service execution
+  - 2.4 Definition of IN service creation/management related functional entities
+
+- 3 Functional entity call/service logic processing models
+    - 3.1 General
+    - 3.2 Modelling objectives/criteria
+      - 3.2.1 Call modelling objectives/criteria
+      - 3.2.2 Modelling of service logic processing objectives/criteria
+    - 3.3 General assumptions
+      - 3.3.1 Scope of functional entity call/service logic processing models
+      - 3.3.2 Relation to IN conceptual model
+      - 3.3.3 Use of functional entity call/service logic processing models
+      - 3.3.4 Other considerations
+    - 3.4 Overview of call/service logic processing related functional entities
+    - 3.5 Call/service logic processing functional entity models
+  - 4 Relationship between functional entities
+    - 4.1 General
+    - 4.2 Relationships
+    - 4.3 Information flows between functional entities
+  - 5 Mapping the global functional plane to the distributed functional plane
+    - 5.1 Mapping requirements
+    - 5.2 Relationship to IN conceptual model
+    - 5.3 An example of mapping some selected SIBs to functional entities
+- Annex A – Example basic call state model (BCSM)
+- Annex B – Object-oriented finite state machine modelling
+- Annex C – Call segment model
+
+### **Q.1205 – Intelligent Network physical plane architecture**
+
+- 1 General
+- 2 Requirements and assumptions
+  - 2.1 Requirements
+  - 2.2 Assumptions
+- 3 Physical entities (PEs)
+- 4 Mapping the distributed functional plane to the physical plane
+  - 4.1 Mapping of functional entities to physical entities
+  - 4.2 Selection of underlying protocol platforms
+- 5 User interfaces
+
+### **Q.1208 – General aspects of the Intelligent Network application protocol**
+
+- 1 Introduction
+- 2 Background
+- 3 Definition methodology
+- 4 Evolutionary requirements
+
+### **Q.1210 – Q.1210-series Intelligent Network Recommendation structure**
+
+- 1 General Q.1200-series structure
+- 2 Q.121x-series Intelligent Network Recommendation overview
+
+### **Q.1220 – Q.1220-series Intelligent Network Capability Set 2 Recommendation structure**
+
+- 0 Introduction
+- 1 General Q.1200-series structure
+- 2 Q.121x-series Intelligent Network Recommendation overview
+
+### **Q.1230 – Q.1230-series Intelligent Network Capability Set 3**
+
+- 1 General Q.1200-series structure
+- 2 Q.123x-series Intelligent Network Recommendation overview
+
+### **Q.1290 – Glossary of terms used in the definition of Intelligent Networks**
+
+- 1 General
+  - 1.1 Introduction
+  - 1.2 Conventions
+- 2 Terms and definitions (listed alphabetically)
+
+Annex A – Acronyms
+
+
+
+# ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| <b>Series Q</b> | <b>Switching and signalling</b>                                                                                                |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| Series T        | Terminals for telematic services                                                                                               |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**Q.1208**
+
+(09/97)
+
+SERIES Q: SWITCHING AND SIGNALLING
+
+Intelligent Network
+
+# --- **General aspects of the Intelligent Network Application protocol**
+
+ITU-T Recommendation Q.1208
+
+(Previously CCITT Recommendation)
+
+---
+
+## ITU-T Q-SERIES RECOMMENDATIONS
+
+## **SWITCHING AND SIGNALLING**
+
+|                                                          |                      |
+|----------------------------------------------------------|----------------------|
+| SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE           | Q.1–Q.3              |
+| INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING       | Q.4–Q.59             |
+| FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN | Q.60–Q.99            |
+| CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS             | Q.100–Q.119          |
+| SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5     | Q.120–Q.249          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 6                | Q.250–Q.309          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R1                   | Q.310–Q.399          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R2                   | Q.400–Q.499          |
+| DIGITAL EXCHANGES                                        | Q.500–Q.599          |
+| INTERWORKING OF SIGNALLING SYSTEMS                       | Q.600–Q.699          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 7                | Q.700–Q.849          |
+| DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1               | Q.850–Q.999          |
+| PUBLIC LAND MOBILE NETWORK                               | Q.1000–Q.1099        |
+| INTERWORKING WITH SATELLITE MOBILE SYSTEMS               | Q.1100–Q.1199        |
+| <b>INTELLIGENT NETWORK</b>                               | <b>Q.1200–Q.1999</b> |
+| BROADBAND ISDN                                           | Q.2000–Q.2999        |
+
+*For further details, please refer to ITU-T List of Recommendations.*
+
+## **ITU-T RECOMMENDATION Q.1208**
+
+# **GENERAL ASPECTS OF THE INTELLIGENT NETWORK APPLICATION PROTOCOL**
+
+## **Summary**
+
+The objective of this Recommendation is to specify the definition methodology to be applied to the Intelligent Network application protocol Recommendations defined in specific capability sets. This Recommendation is not expected to change greatly in future versions with the possible exception of additional specification mechanisms.
+
+Associated standardization work is contained in all of the Q.12xx IN Recommendations and more particularly in the Q.12x8 INAP Recommendations.
+
+### **Source**
+
+ITU-T Recommendation Q.1208 was revised by ITU-T Study Group 11 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 12th of September 1997.
+
+## FOREWORD
+
+ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
+
+The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 1998
+
+All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
+
+## CONTENTS
+
+|                                                                      | <i>Page</i> |
+|----------------------------------------------------------------------|-------------|
+| 1 Introduction .....                                                 | 1           |
+| 2 Background.....                                                    | 1           |
+| 3 Definition methodology.....                                        | 1           |
+| 4 Evolutionary requirements .....                                    | 1           |
+| 4.1 Rules for adding new parameters to INAP.....                     | 2           |
+| 4.2 Rules/guidelines for development of IN call party handling ..... | 2           |
+
+
+
+# **GENERAL ASPECTS OF THE INTELLIGENT NETWORK APPLICATION PROTOCOL**
+
+*(revised in 1997)*
+
+## **1 Introduction**
+
+This Recommendation defines the general aspects of the interfaces and protocols. For the detailed protocols and interfaces supported in each capability set, refer to the Q.12x8 Recommendation for that capability set.
+
+## **2 Background**
+
+All the work on interface specifications is based on the IN Functional Model (INFM). Each capability set will support a number of the interfaces defined in that model appropriate to the requirements placed upon that capability set.
+
+## **3 Definition methodology**
+
+The definition of the protocol can be split into three sections:
+
+- the definition of the service which the protocol provides (primitives etc.);
+- the definition of the operations transferred between entities;
+- the definition of the actions taken at each entity as a result of performing the operations.
+
+The primitives are defined in a tabular notation and may be omitted. The operation definitions are in Abstract Syntax Notation 1 (ASN.1, see Recommendation X.680). The actions are defined in terms of state transition diagrams. Other definition techniques may be used in future capability sets to supplement or replace these if this seems appropriate.
+
+The INAP is a ROSE user protocol (see Recommendation X.219/X.229). The ROSE protocol is contained within the component sublayer of TCAP (see Recommendations Q.771 to Q.775) and DSS 1 (Recommendation Q.932). At present the ROSE APDUs are conveyed in transaction sublayer messages in SS No. 7 and in the Q.931 REGISTER, FACILITY and call control messages in DSS 1. Other supporting protocols may be added at a later date.
+
+The INAP (as a ROSE user) and the ROSE protocol have been specified using ASN.1. At present, the only standardized way to encode the resulting PDUs is the basic encoding rules (see Recommendation X.690). The protocols should be defined in such a way that the functional entities defined in the INFM may be mapped into physical entities in any way that operators and manufacturers desire.
+
+## **4 Evolutionary requirements**
+
+The use of the application context negotiation mechanism (as defined in the Q.77x-Series Recommendations) allows the two communicating entities to identify exactly what their capabilities (and therefore the capabilities required on the interface) are. Where possible, this should be used to allow evolution through capability sets.
+
+Capability sets should always be defined as supersets of previous capability sets to ensure successful interworking with previous capability sets is possible. This may not apply where errors are found in previous capability sets.
+
+### 4.1 Rules for adding new parameters to INAP
+
+The objective of the rules is to achieve alignment and to avoid clashes between ITU-T CS-x and implementations based upon the regional standards that emanated from earlier versions of CS-x Recommendations. For network-specific parameters which are included in the Recommendations, context specific tags will be used. Rules for context specific tagging are:
+
+- 1) Originally defined Q.12x8 tag values shall be maintained in subsequent capability sets.
+- 2) In case parameters are removed from a defined Q.12x8, the corresponding tag values remain reserved.
+- 3) In case a regional defined parameter is adopted by the ITU-T, the regional defined tag values are also considered.
+- 4) The following structure for tag value allocation shall be used:
+
+![Diagram showing tag value allocation for INAP parameters. It is divided into three sections: 'Q.1218 parameters' (tags 0, 1, 2, ..., x), 'Regional standard adopted parameters' (tags ..., 30), and 'Future Capability Set use' (tags 31, ..., n ...). Arrows indicate the flow and scope of each section.](d0abac95583b52a3b35f74a215567334_img.jpg)
+
+|                   |   |   |     |                                         |     |    |                           |           |  |
+|-------------------|---|---|-----|-----------------------------------------|-----|----|---------------------------|-----------|--|
+| Q.1218 parameters |   |   |     | Regional standard<br>adopted parameters |     |    | Future Capability Set use |           |  |
+| →                 |   |   |     | ←                                       |     |    | →                         |           |  |
+| 0                 | 1 | 2 | ... | x                                       | ... | 30 | 31                        | ... n ... |  |
+
+Diagram showing tag value allocation for INAP parameters. It is divided into three sections: 'Q.1218 parameters' (tags 0, 1, 2, ..., x), 'Regional standard adopted parameters' (tags ..., 30), and 'Future Capability Set use' (tags 31, ..., n ...). Arrows indicate the flow and scope of each section.
+
+When a new data type is to be added to an existing sequence of data types with an extension marker (...) and the new data type can be ignored when the receiving system is an implementation of an older INAP version, the new data type shall be added at the end of the sequence, after the extension marker. When the new data type cannot be ignored, the new data type shall be positioned before the extension marker, before the last mandatory parameter. The ITU-T shall allocate tag values starting from 0 upwards (as shown above). Regional bodies may then use tag values from 30 downwards for their additions to the Q.12x8 Recommendation. If the ITU-T adopts a parameter for INAP from such a regional standard, the tag value will also be adopted, in order to ensure compatibility. When all tag values from 0 to 30 have been allocated between Q.12x8 and regional standards, tag allocation by the ITU-T will continue from 31 upwards.
+
+### 4.2 Rules/guidelines for development of IN call party handling
+
+The information used to synchronize the SSF and SCF with the Connection View State should be as generic as possible, to allow flexibility. Allowing different operators to support differing transitions and priorities for feature interactions, thereby enabling competition. The IFs and IEs should specify the modified use of Legs and Call Segments by LegID and Call Segment ID. This also applies to commands initiated by the SCF, both bidirectional (class 1) and unidirectional (class 2) messages.
+
+These requirements also provide a flexible view to evolve to the IN/B-ISDN requirements being developed by the ITU-T, where the addition and removal of parties and bearers should be completely flexible.
+
+## ITU-T RECOMMENDATIONS SERIES
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of the ITU-T                                                                                          |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Transmission of television, sound programme and other multimedia signals                                                       |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| <b>Series Q</b> | <b>Switching and signalling</b>                                                                                                |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| Series T        | Terminals for telematic services                                                                                               |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure                                                                                              |
+| Series Z        | Programming languages                                                                                                          |

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+
+
+![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines.
+
+ITU logo
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**Q.1702**
+
+(06/2002)
+
+SERIES Q: SWITCHING AND SIGNALLING
+
+Signalling requirements and protocols for IMT-2000
+
+---
+
+**Long-term vision of network aspects for  
+systems beyond IMT-2000**
+
+ITU-T Recommendation Q.1702
+
+---
+
+# ITU-T Q-SERIES RECOMMENDATIONS
+
+## SWITCHING AND SIGNALLING
+
+|                                                                                |                      |
+|--------------------------------------------------------------------------------|----------------------|
+| SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE                                 | Q.1–Q.3              |
+| INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING                             | Q.4–Q.59             |
+| FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN                       | Q.60–Q.99            |
+| CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS                                   | Q.100–Q.119          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 4                                      | Q.120–Q.139          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 5                                      | Q.140–Q.199          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 6                                      | Q.250–Q.309          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R1                                         | Q.310–Q.399          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM R2                                         | Q.400–Q.499          |
+| DIGITAL EXCHANGES                                                              | Q.500–Q.599          |
+| INTERWORKING OF SIGNALLING SYSTEMS                                             | Q.600–Q.699          |
+| SPECIFICATIONS OF SIGNALLING SYSTEM No. 7                                      | Q.700–Q.799          |
+| Q3 INTERFACE                                                                   | Q.800–Q.849          |
+| DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1                                     | Q.850–Q.999          |
+| PUBLIC LAND MOBILE NETWORK                                                     | Q.1000–Q.1099        |
+| INTERWORKING WITH SATELLITE MOBILE SYSTEMS                                     | Q.1100–Q.1199        |
+| INTELLIGENT NETWORK                                                            | Q.1200–Q.1699        |
+| <b>SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000</b>                      | <b>Q.1700–Q.1799</b> |
+| SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) | Q.1900–Q.1999        |
+| BROADBAND ISDN                                                                 | Q.2000–Q.2999        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **ITU-T Recommendation Q.1702**
+
+# **Long-term vision of network aspects for systems beyond IMT-2000**
+
+## **Summary**
+
+This Recommendation addresses the envisaged network environment, network design objectives, and architecture concepts of Systems Beyond IMT-2000. This Recommendation, together with a draft ITU-R Recommendation which covers the radio aspects, form the ITU long-term vision for Systems Beyond IMT-2000.
+
+## **Source**
+
+ITU-T Recommendation Q.1702 was prepared by ITU-T SSG (2001-2004) and approved under the WTSA Resolution 1 procedure on 29 June 2002.
+
+## **Keywords**
+
+Long-Term Vision, Network Aspects, Systems Beyond IMT-2000
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 2002
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+###### Page
+
+|     |                                                             |   |
+|-----|-------------------------------------------------------------|---|
+| 1   | Scope .....                                                 | 1 |
+| 2   | References.....                                             | 1 |
+| 3   | Definitions .....                                           | 1 |
+| 4   | Abbreviations.....                                          | 2 |
+| 5   | Envisaged network environment around the year 2010 .....    | 2 |
+| 5.1 | Market trends.....                                          | 2 |
+| 5.2 | Technology trends .....                                     | 3 |
+| 6   | Key long-term network design objectives .....               | 3 |
+| 6.1 | Broadband and multiple bearer service capability .....      | 3 |
+| 6.2 | Service expandability and application service support ..... | 4 |
+| 6.3 | Security support.....                                       | 4 |
+| 6.4 | User platform support.....                                  | 4 |
+| 6.5 | High performance and system efficiency .....                | 4 |
+| 6.6 | System flexibility.....                                     | 4 |
+| 6.7 | System scalability.....                                     | 6 |
+| 6.8 | System interoperability.....                                | 6 |
+| 6.9 | System robustness .....                                     | 6 |
+| 7   | Long-term network architecture concepts .....               | 6 |
+
+# **Introduction**
+
+The ITU-T and ITU-R have collaborated to develop a single ITU vision of Systems Beyond IMT-2000 targeted for initial deployment around the year 2010, subject to market considerations. This common ITU Vision is the nucleus and foundation for the development of related Recommendations in both the Telecommunication Standardization Sector and the Radiocommunication Sector. This relationship is responsive to ITU-T Resolution 38 and ITU-R Resolution 50 which require the development of roadmaps on IMT-2000 in an independent, but well-coordinated manner.
+
+There is a definite trend towards integration of access networks (e.g., cellular, wireless local area network, personal area wireless network, satellite systems, and Internet.) Based on this trend, it is envisioned that the network environment of Systems Beyond IMT-2000 will consist of packet-based network infrastructure offering a plethora of converged services.
+
+# Long-term vision of network aspects for systems beyond IMT-2000
+
+# 1 Scope
+
+The scope of this Recommendation is to provide a long-term vision (around the year 2010) for the network aspects of Systems Beyond IMT-2000. The further development of existing IMT-2000 systems is not addressed by this Recommendation.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published.
+
+- [1] ITU-T Recommendation X.233 (1997) *Information technology – Protocol for providing the connectionless-mode network service: Protocol specification.*
+- [2] ITU-T Recommendation I.113 (1997) *Vocabulary of terms for broadband aspects of ISDN.*
+- [3] ITU-T Recommendation H.323 (2000) *Packet-based multimedia communications systems.*
+- [4] ITU-R Recommendation M.687-2 (1997) *International Mobile Telecommunications-2000 (IMT-2000).*
+- [5] ITU-R Recommendation M.1311 (1997) *Framework for modularity and radio commonality within IMT-2000.*
+
+# 3 Definitions
+
+This Recommendation defines the following terms:
+
+**3.1 converged services:** The integration of Internet, multimedia, e-mail, presence, instant messaging, m-commerce, etc., services with voice service.
+
+**3.2 mobility:** The ability to provide services irrespective of changes that may occur by user/terminal's activities.
+
+**3.3 multicast:** Data transmission to one or more destinations in a selected group in a single service invocation. [1]
+
+**3.4 multimedia:** The combination of multiple forms of media such as audio, video, text, graphics, fax, and telephony in the communication of information.
+
+**3.5 multimedia service:** A service in which the interchanged information consists of more than one type, such as text, graphics, sound, image and video. [2]
+
+**3.6 seamless service:** Seamless Service will prevent users from experiencing any service disruptions while maintaining mobility or portability.
+
+**3.7 session continuity:** The ability of the user to maintain continuity of ongoing sessions while changing between terminal devices and across various access and core networks. For example, the user of a mobile terminal may wish to switch from his mobile equipment attached to a wireless network to a laptop connected to a wire-line or Digital Subscriber Line connection. This should be
+
+supported without any session discontinuity.
+
+**3.8 unicast:** A process of transmitting messages from one source to one destination. [3]
+
+**3.9 virtual reality services:** The ability for users to access the sights and sounds of remotely located complex systems in real-time.
+
+# 4 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+|       |                                                          |
+|-------|----------------------------------------------------------|
+| API   | Application Programming Interface                        |
+| ASP   | Application Service Provider                             |
+| IMT   | International Mobile Telecommunications                  |
+| IP    | Internet Protocol                                        |
+| Mbps  | Mega bits per second                                     |
+| OAM&P | Operations, Administration, Maintenance and Provisioning |
+| PAN   | Personal Access Network                                  |
+| QoS   | Quality of Service                                       |
+| WLAN  | Wireless Local Area Network                              |
+
+# 5 Envisaged network environment around the year 2010
+
+The following network environment around the year 2010 is envisaged to facilitate the identification of future needs of users, service capabilities, and network capabilities at that time.
+
+## 5.1 Market trends
+
+- High-speed data connection is a norm in accessing multimedia services and Internet services, even in the wireless environment, due to additional spectrum, efficient spectrum utilization, and advanced radio technologies. Because of these advancements, "Virtual Reality Services" becomes widely available.
+- The core network is fully Internet Protocol (IP)-based and service provisioning is distributed around the core network. Wireless access is just one of the access methods to the IP-based core network, services, and applications.
+- There exist many complementary wireless networks for voice and data applications in addition to International Mobile Telecommunications-2000 (IMT-2000) terrestrial and satellite-based systems. Some examples are Bluetooth and Wireless Local Area Network (WLAN). A limited integration among these wireless networks and IMT-2000 systems exists.
+- Digital TV with data service capability is ubiquitous.
+- The number of users around the year 2010 could grow to more than 1700 million wireless subscribers with a great number of them having several different terminals for communications. A majority of the user populations is computer proficient and quick to adopt of advanced technologies to enhance quality of life and productivity.
+- There exist Application Service Providers (ASPs) utilizing mobile networks as a means to offer unique services taking advantage of mobile terminal capabilities and location information.
+- Large numbers of users move internationally wanting to use their services anytime anywhere with their personal terminals.
+
+- Services are the driver: the role of technology is to enable provision of services (and capacities) that the users are willing to pay for.
+
+## 5.2 Technology trends
+
+- Software-defined radio technology has become a main element in the wireless infrastructure and handset implementations. Because of this technology, new and advanced radio technologies are easily introduced and deployed by the Network operators and Service providers to differentiate their services.
+- Mobile terminals may form a closed network, or an *ad hoc* network, which enables direct communications between them. Transmission speed could be independent between an uplink and a downlink. Systems Beyond IMT-2000 are expected to act as platforms to effectively deliver traffic within and between the *ad hoc* networks and to offer additional values to them, such as advanced mobility management techniques.
+- Mobility management will be more than supporting higher speed objects such as vehicles. It will be needed to support applications with very large IP multimedia traffic needs, and with diversified communications including person-to-person, machine-to-machine, machine-to-person and vice versa.
+- The concept of seamless services will be extended beyond handover and roaming services.
+- Diverse end-users' individual needs will require flexibility to deal with their preferences or contexts.
+- The following network security environment around the year 2010 is envisaged:
+  - Highly efficient security mechanisms are available in a multimedia environment to process high-speed and high volume information flows.
+  - There exist user transparent access authentication and authorization mechanisms to provide protection in different access environments.
+  - The security infrastructure is supported across service providers.
+  - The capacity of security servers is scaled to provide service for massive network usage.
+  - Seamless security is available to maintain the same security strength with unreduced performance in handover procedures.
+
+# 6 Key long-term network design objectives
+
+The set of network capabilities existing for current IMT-2000 Family Member Systems should be included for Systems Beyond IMT-2000, as needed. The key long-term network design objectives for Systems Beyond IMT-2000 are listed in the following subclauses.
+
+## 6.1 Broadband and multiple bearer service capability
+
+- Access is based on advanced radio access technologies that can enable transmission speeds well beyond the current IMT-2000 radio access target speeds of 2 Mega bits per second (Mbps).
+- Access support includes the ability to handle the diverse Quality of Service (QoS) needs of future applications, including considerations for:
+  - non-real-time / best effort service,
+  - quasi-real-time (such as streaming) service, and
+  - real-time service (such as voice and video telephony)
+- Cooperation with broadcast networks (hybrid networks) is included to open up new applications (e.g., navigation, traffic information, interactive multimedia services.)
+
+## 6.2 Service expandability and application service support
+
+- Encourages appearances of diversified ASPs by supporting their services and offering additional values to them.
+- Provides multiple service combination capabilities with appropriate mechanisms to handle service interaction and service invocation.
+  - Traditional telecommunications service invoking methods are mostly based on service Application Programming Interface (API) and its capabilities. In service provisioning components, the objective is changed to provide flexible service provisioning based on trigger objects, which will enable automatic interaction and invoking of a series of service logic instances that might be fully distributed in different elements.
+  - Service interactions will support variable exchange of information element types.
+  - Service combinations may be created dynamically, based on a user's profile/situation selections that best fit the user's present usage environment. Users can also build a situation profile in a real-time fashion.
+  - The service combination capability should support backward compatibility with existing service platforms.
+- Supports modularized service control and open service architecture.
+- Simplifies service expansion and dynamic creation of multi-facet services at session level.
+- Supports flexibility for adoption of new services.
+- Provides seamless service capabilities across networks.
+
+## 6.3 Security support
+
+Provides seamless security protection in Systems Beyond IMT-2000 networks.
+
+## 6.4 User platform support
+
+- Mobile users may form a closed *ad hoc* network and communicate directly with each other within that *ad hoc* network. In addition, these users may also wish to communicate normally for conventional communication. Such access requirements must be supported.
+- A group of users may move collectively with respect to a core network (e.g., users in a train, aeroplane, ship, etc.) Such a group may be open or closed. Systems beyond IMT-2000 should accommodate the access requirements of such users. [4]
+- User platforms should provide a natural communication-oriented man-machine interface.
+
+## 6.5 High performance and system efficiency
+
+- Efficient handling of very large IP multimedia traffic with various predefined service parameters.
+- Support of a wide range of traffic ratios within the network, including unicast, multicast, broadcast and bursty traffic.
+- Distributing service provisioning according to provider's resource control policy.
+
+## 6.6 System flexibility
+
+- Support Moving Networks:
+  - A Moving Network is a network that can move in the same manner as a terminal in mobile systems. For example, a Moving Network could be in a train, ship or aeroplane, etc.
+- Accommodate diverse access technologies/schemes.
+
+- A key long-term network design objective for Systems Beyond IMT-2000 should be its flexibility to accommodate diverse access technologies/schemes.
+- Future mobile devices are expected to support numerous access technologies (including a variety of wireless and/or wire-line choices.) A key network design goal should be to facilitate a judicious choice of appropriate access technology for a particular usage environment. The choice should be based on:
+  - a) availability of access technologies at the mobile user location,
+  - b) speed and QoS requirements of the user application,
+  - c) cost of using the access technology, etc.
+- Separate control and transport functions.
+  - Control functions in the IP-based network platform should be open to support various existing and future evolution signalling systems, and its function will be more focused on signalling processing.
+  - Transport functions should fully utilize IP transport capability to direct user traffic flows to their proper destinations.
+  - The interface between control and transport functions should be open and standardized.
+  - When the control and transport functions are implemented in the same physical equipment, the interface(s) between them still should be opened.
+- Facilitate support of multiple switching control methods, signalling at different layers and their combinations.
+  - Switching components in the IP-based network platform may provide multiple switching control methods, and may also provide interoperation among these methods.
+  - Switching control methods may be implemented according to their service support requirements, and thus, may be functioning at different internetworking layers.
+  - The usage of IP transport for various switching control signalling should be used according to service requirements.
+- Support open interface for roaming and handover among various networks.
+- Automatically manage the access means (including both wired access and wireless access) based on user defined criteria such as cost, speed, QoS, privacy, applications, etc.
+- Have flexible, efficient, and integrated mobility management, i.e., flexibility to support advanced mobility management schemes including:
+  - Location Management:
+    - Location Registration;
+    - Paging.
+  - Routing Management:
+    - Handover.
+  - Session Continuity:
+    - Seamless Session Transfer;
+    - Diversity Handover across access and core networks;
+    - Having a flexible, efficient, and integrated mobility management, i.e., flexibility to support advanced mobility management.
+  - Support an efficient and adaptive combination of location registration and IP paging functions.
+  - Support dynamic network capacity changes.
+
+## 6.7 System scalability
+
+Systems Beyond IMT-2000 are expected to handle very large amounts of multimedia traffic to/from a large number of mobile users. The multimedia applications run by the mobile users will have diverse traffic and performance/QoS requirements. Advanced mobility management techniques are needed to handle the QoS requirements (e.g., satisfying QoS requirements of a mobile application during a sequence of handovers.) The system must also take into consideration all the access technology choices the user may have in a particular network environment. Advanced mobility management schemes are needed to handle multicast and broadcast requirements of geographically dispersed mobile multimedia users.
+
+## 6.8 System interoperability
+
+- Support global standards, e.g., standardized interfaces between networks.
+- Effective and user-friendly Operations, Administration, Maintenance and Provisioning (OAM&P) facilities.
+- Interoperability with existing third generation mobile networks. Interoperability in this case means the availability of well-defined gateway points and functions between both networks.
+- Integration/inter-operation with alternative networks, e.g., a Personal Access Network (PAN), a WLAN.
+
+## 6.9 System robustness
+
+Provide network security among heterogeneous inter-connected networks. The security objectives shall include the following aspects:
+
+- Comprehensive and cross-provider security infrastructure support.
+- Well-defined and conducted routine system risk analysis.
+- Robust system intrusion monitoring and response system to control damage.
+- Low overhead security protocols to accommodate wireless bandwidth limitation.
+- Provide seamless security across heterogeneous access technologies.
+
+# 7 Long-term network architecture concepts
+
+The network part of Systems Beyond IMT-2000 will be flexible, versatile and new services will be easy-to-deploy. Systems Beyond IMT-2000 are likely to be realized according to the following general principles:
+
+- Network architecture based on IP technology;
+- Modular construction using expandable components; and
+- Open interfaces between various systems.
+
+An IP-based network concept is likely to be used for future development and standardization efforts.
+
+The high-level architecture of Systems Beyond IMT-2000 may be envisaged to include user platform, IP-based network platform, and service provisioning platform. The IP-based network platform includes two types of components: access network components and core network components.
+
+The user platform allows a user to gain access to services in conjunction with the access and core networks. User platform can be subdivided into a number of components.
+
+Access network components are access technology dependent. They include multiple wireless and wire-line access technologies. Core network components are access technology independent. They
+
+include functional components such as control functions and transport functions.
+
+It is anticipated that radio access components of Systems Beyond IMT-2000 can dynamically support various radio transmission requirements. In addition to these radio access components, other access components to provide interconnection with other fixed networks are also needed in the IP-based network platform. [5]
+
+Core network components will provide control functions and transport functions.
+
+It is envisaged that a service provisioning mechanism that can dynamically provide user-defined combined multiple media services at a session level is needed. The service provisioning platform supports such a multiple service combination capability.
+
+Service provisioning mechanisms in Systems Beyond IMT-2000 are envisaged to become more flexible in a multi-stage distributed manner. Such a distributed service provisioning platform is expected to help explore the network service potential of Systems Beyond IMT-2000.
+
+
+
+
+
+## **SERIES OF ITU-T RECOMMENDATIONS**
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                              |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                    |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| <b>Series Q</b> | <b>Switching and signalling</b>                                                                                                |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| Series T        | Terminals for telematic services                                                                                               |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| Series Y        | Global information infrastructure and Internet protocol aspects                                                                |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                           |