Addressing resources

Communication parameters and numbering elements such as code numbers, subscribers' telephone numbers and short numbers.

ADMD (Administration Management Domain)

Administration Management Domains (ADMDs) manage smaller units of a Message Handling System (MHS). They provide message transfer services for other supply areas. The International Telecommunication Union (ITU) is responsible for public management domains (ADMD). ADMD names are names of providers of X.400/ISO 10021 messaging services.


Asymmetrical Digital Subscriber Line

Aereonautical radio

Includes all radio services for civil aviation radio services, such as flight safety, airline aircraft, private planes and gliders, balloons and hang gliders.

Amateur radio

Experimental technical radio service with certificate of competence on bands, some exclusively allocated, in the entire frequency spectrum.

Amateur radio

Experimental technical radio service with certificate of competence on bands, some exclusively allocated, in the entire frequency spectrum.


Picture or audio signals are converted into electromagnetic oscillations and then broadcast using frequencies (or via cables).


Bluetooth technology is an open standard which enables voice and data transmissions to be established between computers and their peripherals and with all types of electronic equipment via a short-range radio link.


WiMAX (which stands for Worldwide Interoperability for Microwave Access) is one of these broadband radio access technologies grouped together under the name BWA (Broadband Wireless Access). The documents published under this heading provide a brief description of these technologies and a list of frequently asked questions.

Cable ducts

Underground pipes in which lines for transmission of information by telecommunications techniques are conveyed, including the access shaft.

Call-by-call (or manual) carrier selection


Country Code Top Level Domain or geographical top-level domain name: Top level domain name category (TLD) designating a country or a region. The designations of the ccTLDs correspond to the ISO-3166 standard (e.g.: ".ch" for Switzerland, ".fr" for France or ".de" for Germany.


European Conference of Postal and Telecommunications Administrations.

Citizens' band radio

Licensed 40-channel short-distance radio service for general use in the 27 MHz range.

Codice Interlock CUG (Closed User Group Interlock Code)

Signalling System 7 parameter in accordance with ITU-T Recommendation Q.700.


Federal Communications Commission.

Communication parameters

Elements that enable the persons taking part in a telecommunications operation, as well as the computer processes, machines, apparatus or telecommunications equipment involved, to be identified

Conformity assessment procedure

Conformity assessment procedures determine whether telecommunications equipment meets the applicable technical requirements.


Acronym for Digital Audio Broadcasting. Standard procedure for the digital transmission of radio signals developed in the EU research initiative, EUREKA 147.

DCC (Data Country Code)

Designation of the format of an NSAP address for national OSI networks.

Declaration of conformity

The objective of the declaration shall be to indicate that the product concerned is in conformity with standards or other normative documents to which the declaration refers.


Digital European Cordless Telecommunication interface, mainly in the 1.88 to 1.9 GHz frequency band. This interface may also be used for other applications.


DIT (Directory Information Tree)

Structure of the global directory in accordance with ITU-T Recommendation X.500 and ISO Standard 9594.

DNIC (Data Network Identification Code)

Code to identify a data transmission network in accordance with ITU-T Recommendation X.121.


Domain Name System. Computers connected to the internet communicate with each other using the Internet Protocol (IP) and IP addresses, which uniquely identify every computer. Since it is difficult to memorise these addresses, the DNS enables internet users to use domain names consisting of words (letters and possibly numbers) instead of IP addresses consisting solely of numbers. The conversion of a domain name into the corresponding IP address takes place automatically via the name servers which make up the DNS.


The entirety of the computers connected to the internet which share a common characteristic. The domain name system consists of numerous hierarchically organised domains and subdomains. In the example, "ch" represents the top-level domain and "admin" the second level domain. The domain name makes the internet easier to use, as if the user knows the domain name he does not have to resort to the corresponding IP address.

Domain names

Computers connected to the internet communicate with each other using "Internet Protocol" and always have an IP address, or rather an IP number, for example, which is assigned by the ISP (Internet Service Provider). A domain name is therefore a type of address on the internet.

DSA (Directory System Agent)

First level DSA: Ddrectory system which enables entries in the global directory in accordance with ITU-T Recommendation X.500 and ISO/IEC Standard 9594. Second level DSA: Directory system situated below the first level DSA hierarchy.


Abbreviation for Digital Video Broadcasting – a technique developed and standardised by an international DVB project group, for digital transmission of TV signals.


"Digital Video Broadcasting Handheld" is a standard for transmitting digital TV to mobile terminal equipment. The European Telecommunications Standards Institute gave its approval to DVB-H in November 2004. Whereas UMTS is particularly suitable for transmitting individual services, DVB-H is characterised by its ability to deliver data to a large number of users simultaneously.


"Digital Video Broadcasting Terrestrial", standard procedure for the digital transmission of TV signals developed by the DVB project group. T stands for terrestrial broadcasting. DVB can also be broadcast by satellite (DVB-S) and cable (DVB-C).

Electronic signature

The electronic signature is a technical procedure which makes it possible to guarantee the authenticity of a document or an electronic message and to ensure the identity of the sender.


"Electromagnetic compatibility", the capacity of electronic equipment to function correctly in the electromagnetic environment (artificially generated electromagnetic fields, for example transmitter installations) without itself generating electromagnetic interference which affects other equipment operating in this environment.


"European Telecommunications Standards Institute". European agency responsible for standardisation of telecommunications.

Failure to comply with regulations

Anyone who, intentionally or out of negligence, infringes any other provision of the legislation on telecommunications, a treaty or international agreement on the subject, or violates a decision taken on the basis of such provision and notified to him with an indication of the penalties available under this article, shall be liable to a fine not exceeding CHF 5000.

Fast bitstream access

Establishment of a high-speed connection to the subscriber from the exchange to the domestic connection on the twisted pair metallic line by a telecommunications service provider and cession of this connection to another provider for the provision of broadband services.


The number of periodic changes in electrical current or in a sound wave per unit of time; the unit of measurement is the Hertz (Hz).

Frequency allocation plan

The frequency allocation plan specifies the allocation of frequency ranges to various radio services.

Fully unbundled access to the local loop

Provision of access to the local loop for another telecommunications service provider for utilisation of the entire frequency spectrum of the twisted pair metallic line


"Global Positioning System", system originally developed for the US military which allows one's position to be determined world-wide with a positioning accuracy of under 10 metres. 24 satellites are used for positioning. The US Defence Department can determine the accuracy of positioning.


"Global System for Mobile communications", digital cellular radio technology. Operates in the 900 MHz waveband.

GSM-R (Global System for Mobile Communication Railway)

Private mobile radio system for railway operators based on the GSM standard.


Generic Top Level Domain: top-level domain name (TLD) category which designates the type of organisation which a website services (e.g. ".com", ".net", ".info").


Internet Corporation for Assigned Names and Numbers: an American not-for-profit corporation which is responsible for coordinating the internet addressing system in general and domain names in particular.

ICD (International Code Designator)

Designation of the format of an NSAP address for multinational OSI networks.


Internationalised Domain Name. An Internationalised Domain Name is an internet domain name which may include special characters which are not defined in the ASCII standard. These special characters include, in particular, accented characters (e.g. é, à) or umlauts (e.g. ü, ä), which are common in numerous European languages, including German and French, and characters which do not form part of the Latin alphabet, such as Cyrillic, Chinese or Arabic characters.


International Electrotechnical Commission

IIN (Issuer Identifier Number)

Identification number for issuers of international telecommunications credit cards in accordance with ITU-T Recommendation E.118 and ISO Standard 7812–2.

Information society

"Information society" describes the form of society being created in the "information age", based mainly on the increasingly interactive acquisition, storage, processing, transmission, distribution and use of information and knowledge, in which a productive relationship between information resources and knowledge-intensive production play a major role.


"Installation" (or establishing): putting telecommunications equipment into working condition, especially by repairing them.


Interlinking of the equipment and services of two providers of telecommunication services to enable technical and logical interaction of the connected parts and services as well as access to third-party services.

Intermediate network

Decoupling network for Signalling System 7 (SS7) in accordance with ITU-T Recommendation Q.700.


The ability to communicate between all users of the services forming part of the universal service.


Internet Protocol. A network protocol widely used in computer networks such as the internet.

IP address

The IP (Internet Protocol) address is the number which identifies any hardware (computer, router, printer etc.) which is connected to a network which operates this protocol. It is used for sending data to this address. The Version 4 IP address, which is currently the most widely used, consists of four numbers between 0 and 255, separated by dots. The Version 6 IP address, which can already be used, is longer and considerably increases the number of possible IP addresses.


International Organisation for Standardization

ISPC (International Signalling Point Code)

International signalling point code in accordance with ITU-T Recommendation Q.708.


International Telecommunication Union.


ITU standardisation sector (International Telecommunication Union).

Leased line

(DTS, art 1 para. B / RS 784.101.1) The provision of transmission capacities, as defined by the Council directive of 5 June 1992 on the application of the principle of provision of a network open to leased lines (92/44/CEE).

Leisure-time radiocommunication

Licence-free short-distance radio services for general use in the UHF ranges 433.050 – 434.790 MHz (SRD) and 446.00625 – 446.09375 MHz (PMR).


Federal law on Radio and Television.


Law on Radio and Television

Manufacturer code

Code used in the control procedures for group 3 telex equipment (no standardised instrument) which is specified in ITU-T Recommendation T.35.

Maritime radio

Radio service on ocean-going yachts and ships in medium, short, ultra-short and satellite bands.


"Marketing (or placing on the market)": the transfer or delivery of telecommunications equipment with or without payment.

Market monitoring

OFCOM’s regulatory tasks as part of the market access procedures for telecommunications equipment and the licensing regulations, as well as the radio and television legislation (unlicensed listeners and viewers).

MMS (Multimedia Messaging Service)

Service which allows users to exchange messages containing text, images and sound, generally by using mobile radio terminal equipment.

MNC (Mobile Network Code)

Identification code for public terrestrial mobile telephone networks in accordance with ITU-T Recommendation E.212.

Multi-purpose equipment

Equipment which is suitable for reception of radio and television programme services and for other applications.

NI (Network Indicator)

Network indicator number to differentiate the various signalling networks.


Notification is therefore the process of announcing to the national authority one’s intention to place on the market telecommunications equipment using frequencies whose use is not harmonised at the international level.

NSAP (Network Service Access Point). NSAP address

Information used to identify an OSI network access point.


National Signalling Point Code

Object identifier

Numerical value which enables precise identification of an information element within the framework of a communication processes.


To propose that telecommunications equipment be marketed by exhibiting them on commercial premises, presenting them at exhibitions, in brochures, catalogues, electronic media or in any other way.

Official document

The term official document refers to all information recorded on any media (paper document, but also virtual documents: information contained in a database) held by an authority which is related to the performance of public tasks and is available in its definitive version.


"Operating" is the use of telecommunications equipment irrespective of whether or not the transmission or reception of information is performed successfully

OSI (Open Systems Interconnection)

Totality of standards and models for interconnecting open systems.

PAMR (Public Access Mobile Radio)

Public mobile radio system such as TETRA (Terrestrial Trunked Radio), which corresponds to a standard specified by ETSI.


"Powerline Communications", PLC is a "broadband" technology (e.g. for internet data traffic), which could compete over the "last mile" to end users with other broadband access technologies such as xDSL (broadband technology on ordinary telephone lines) and CATV (broadband technology on the TV cable network).


Digital trunked systems (PMR: Private Mobile Radio and PAMR: Public Access Mobile Radio) were developed for private and public users who have specific requirements regarding operating functions and security. Trunked systems differ from public GSM or UMTS systems in that they are able to rapidly establish a connection, enable group calling, priority calling, end-to-end encryption and offer the possibility of a direct connection between two mobile stations without the need for an intermediate base station (direct mode).


Meeting of the Preparatory Conference (world conference for preparing the WSIS)

PRMD (Private Management Domain). PRMD names

Names of operators of private X.400 /ISO 10021 messaging systems.

Putting into service

"Putting (or bringing) into service": the initial installation and operation of a telecommunications equipment, irrespective of whether or not the transmission or reception of information is performed successfully by the final user.

R&TTE Directive

European directive liberalising assessment of conformity and placing on the European market of terminals and radio equipment.

RDN (Relative Distinguished Name). RDN names

Names of directory entries which are unique as they are related to a specific entry and which form a component of a directory name.

Reception fee

A fee which must be paid by all persons who possess or operate equipment suitable for reception of radio and television programme services.


An accredited body for the registration of second-level domain names within a top-level domain (ccTLD or gTLD).


A body which is used by ICANN for administration of a top-level domain.


Contracts between operators enabling customers to use other mobile telephony networks.


Receiver placed on top of the television set (set-top) which converts digital TV and radio signals to analogue so that the programmes can be used in normal receivers. The set-top box is also used to decode pay programmes using a smartcard.


Short Message System.


The word spam describes an electronic message (e-mail, fax, SMS message or instant message) which is sent to recipients unsolicited or without their consent. Spamming is the sending of such electronic messages to a large number of recipients. The sender of such advertising is termed a spammer.


Broadcasting Corporation


The name of the foundation which was appointed by OFCOM for the assignment and administration of the second-level domain names registered in the ".ch" top-level geographical domain (ccTLD).

Telecommunications equipment

Apparatus, lines or equipment intended for the transmission of information by means of telecommunications techniques or used for that purpose.

Telecommunications service

Transmission of information for third parties by means of telecommunications techniques

TETRA (Terrestrial Trunked Radio)

Professional radiocommunication standard approved by ETSI and generally used for business communication and communication between security services.


Top Level Domain: the highest level in the domain name system. It is sub-divided into numerous sub-domains distributed in the ccTLD and gTLD categories.

T MNC (Tetra Mobile Network Code)

Identification code for a PMR/PAMR radio network in accordance with ETSI ETS Standard 300 392-1.

Transmission by means of telecommunications techniques

Sending or receiving of information by wire, cable or radio, by means of electrical, magnetic or optical signals or other electromagnetic signals.

Transmission obligation

Obligation of a wired network operator, based on a decision by the federal Office of Communications, to transmit a Swiss programme service.


"Universal Mobile Telecommunications System" is the European standard of the IMT2000 family of third generation mobile cellular standards (3G). In addition to the telephony service, UMTS will in particular allow the provision of multimedia services (data, images, sound) at data transfer rates of 144 kbit/s (vehicles), 384 kbit/s (pedestrians) and 2 Mb/s (buildings).


"Ultra-Wide-Band" technology which features transmission of very short-duration pulses (of the order of one billionth of a second). It is becoming very popular for wireless connection of high-speed local area networks (100 Mbit/s to 1 Gbit/s) and also has the amazing ability to penetrate physical objects.


Very High Frequency, the frequency range 88.5 – 108.0 MHz; currently, the normal method for broadcasting stereo radio programmes using analogue techniques (see also FM).


"Voice over Internet Protocol" is a generic name which defines the transportation of voice traffic by means of transmission in packets using Internet Protocol (IP). VoIP traffic can be routed on a managed private network or the internet, which is a public network, or a combination of the two.


"Wireless Local Loop", WLL connection allowing a subscriber to connect to public telecoms networks via a wireless link.


World Summit on the Information Society.


x Digital Subscriber Line - HDSL, ADSL & VDSL Set of techniques and equipment used on a subscriber line enabling the subscriber to set up links with high data rates.

Last modification 05.09.2022

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