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Add/Drop Multiplexer (ADM): equipment on a telecommunications network used for inserting or extracting packets of data.

ADM (Add/Drop Multiplexer): see Add/Drop Multiplexer.

ADSL (Asymmetrical Digital Subscriber Line): ADSL is an xDSL technology used for high-speed transmission of data, particularly when using a subscriber's conventional telephone line consisting of a pair of copper wires. By using two modems, one installed on the subscriber's premises and the other in a DSLAM located in the main distribution frame, ADSL technology is able to increase network bandwidth considerably and obtain transmission speeds up to 160 times faster than with a conventional analogue modem. The principle behind ADSL is that part of the bandwidth is reserved for transporting voice traffic (low frequencies) while another part is used for transporting data (high frequencies) either in the direction of the network backbone (upload) or in the direction of the subscriber (download). The technology is asymmetrical in the sense that the upload bit rate (data sent by the user) is lower than the download rate (data received by the user). For the correct restoration of voice traffic (using the low frequency spectrum), splitters located at each end of the line eliminate those parts of the signal which are not needed.

The bandwidth of the line is divided as follows:

0 – 5 kHz analogue telephone line
30 kHz – 130 kHz narrowband channel in the direction of the network (upload)
30 kHz – 1.1 MHz broadband channel in the direction of the subscriber (download)

FDM (Frequency Division Multiplexing) is used to separate the various data traffic flows. An echo cancellation system is used for spectrum recovery on the upload and download channels.

AFNIC (Association française pour le nommage Internet en coopération – www.afnic.fr): the AFNIC is a non-profit organization whose principal function is establish and implement a naming system for the .fr (France) and .re (Reunion Island) zones. It has drawn up naming charters which sets out its rules for registering domain names in these zones. Members of the AFNIC include service providers who have been accredited as registrars of domain names in the French domain name zones.

ARCEP (Autorité de régulation des communications électroniques et des postes – www.arcep.fr): the ARCEP is an independent administrative authority. It was established on January 5, 1997 and, together with the Minister for Telecommunications, has overall responsibility for regulating the telecommunications sector in France.

ATM (Asynchronous Transfer Mode): this network technology is used for the simultaneous transmission of data, voice and video. It is based on the transmission of signals in short, fixed-length packets. The transmission of these packets is said to be asynchronous because they are transported over different routes and do not necessarily arrive at their destination in the same chronological order as they were sent.


Backbone: network consisting of a number of very high bandwidth links to which other, smaller networks are connected (including metropolitan networks).

Bandwidth: the transmission capacity of a transmission line. It determines the quantity of information (in bits per second) which can be transmitted simultaneously.

Bit: contraction of "binary digit". It is the smallest unit of information processed by a computer. In a binary system, one bit takes the value 0 or 1. Information recorded in digital form is coded in the form of bits. One character (letter or figure) is generally coded as 8 bits (1 byte).

Bit rate: amount of information through a communication channel over a given period of time. The bit rate is measured in bits per second or in multiples thereof (kbits per second = kilobits per second, Mbits per second = megabits per second, Gbits per second = gigabits per second, Tbits per second = terabits per second). The upload bit rate corresponds to the transmission of data from the subscriber to the network and the download bit rate corresponds to information transmitted from the network to the subscriber.

Broadband: The concept of broadband is a relative concept, depending on the status of transmission technology at any given time. At present broadband is generally accepted as corresponding to a bit rate of at least 512 kbits per second. See also "bit rate".
Byte: a set of eight bits. Bytes and their multiples (kilobyte (kB), megabyte (MB), gigabyte (GB), Terabyte (TB), etc.) are used to measure the size of electronic files. When such measurement is given in multiples of bytes, it is generally accepted that a kilobyte is equal to 210, or 1,024, bytes (and not 1,000 bytes), and that a megabyte is equal to 220 bytes (and not 1,000,000 bytes).

Broadband ARPU (Average Revenue per User) includes revenues from the flat-rate package and the value-added services but excludes one-time revenues (e.g. migration from one offer to the other or unsubscription fee) divided by the total number of ADSL subscribers invoiced for the period.


Call termination: This operation consists of the routing of calls to subscribers on a particular network. In principle, call termination requires either that the call be made from the network on which the called party is a subscriber or from a network interconnected with this network.

CNIL (Commission nationale de l'informatique et des libertés – www.cnil.fr): The CNIL (National Commission for Information Technology and Freedom) is an independent administrative authority established by Law No. 78-17 of January 6, 1978, known as the Liberty and Freedom (Informatique et libertés) law. Its principal role is the protection of privacy and of personal or public freedom, and it is responsible for ensuring compliance with the Liberty and Freedom law.

Co-location facilities or space: room located in France Télécom sites containing equipment belonging to third party operators used for unbundling. The room is built by France Télécom who then reinvoices the cost of construction to the operators located in the room. The third party operators then rent whatever space they need (one or more rack spaces occupying a floor area of 600 mm x 600 mm) for their unbundling activities.

Cookie: information recorded by a server in a text file located on the client's computer and which can be read by this same server (and by this server alone) at a later time.

Copper pair: type of cable used for the transmission of electrical signals, consisting of one or more pairs of metal conductors. The two wires forming the pair are braided in order to minimize potential interference between two conductors. By extension, the copper pair also refers to the local loop link between a subscriber and the local concentrator. See also "local loop".

CSA (Conseil supérieur de l'audiovisuel – www.csa.fr): The CSA is an independent administrative authority established by the law of January 17, 1989. Its principal role is to guarantee the freedom of audiovisual communications in France in accordance with the provisions of the Law of September 30, 1986, as amended.


Dark optical fiber: raw optical fiber without the equipment which allows it to be used.

Dedicated facilities or space: room in a France Télécom site containing equipment belonging to a third party operator used for unbundling. Third party operators rent the space (one or more racks each occupying a floor area of 600 mm x 600 mm) necessary for their unbundling activities. See also "co-location facilities".

Digital: coding in binary form (0 or 1) of information to be processed by a computer.

Digital local exchange (LX): switch on the France Télécom telephone network to which subscribers are connected by means of local concentrators. The France Télécom network is organized in a hierarchical fashion, with the digital local exchange being the lowest level in the hierarchy of exchanges installed on the network.

Digital main switching unit (MSU): France Télécom's interconnect point, occupying the highest level in the hierarchy of switches in a trunk exchange area. See also "trunk exchange area".

DNS (Domain Name System): the DNS is a database which registers Internet resources (computer, router, etc.) in the form of a domain name and allocates them a unique IP address. The Internet protocol converts the domain name to the corresponding IP address. Without the DNS, users would have to remember websites or email addresses in the form of the domain's IP address. See also "domain name".

Domain name: a domain name is the unique identifier of an IP address. The DNS (see "DNS – Domain Name System") matches the domain name to the IP address. A domain name consists of a string of characters (from "a" to "z" or "0" to "9", plus "-") corresponding to the name of a trademark, association, company individual, etc., plus a suffix known as the TLD (see "TLD – Top Level Domain"), such as .fr, .de, .net, .com, etc.

Domain name registration: domain name registration consists of hosting domain names on a computer with an IP address on behalf of the domain name owners, who are in turn entered in the register relating to their TLD. See also "TLD".

DSL (Digital Subscriber Line): See xDSL.

DSLAM (Digital Subscriber Line Access Multiplexer): equipment installed in the telephone exchange closest to the subscriber which is part of the equipment used to transform a conventional telephone line into an xDSL line. DSLAMs connect several xDSL lines and are connected to the modem on the subscriber's premises via the local loop.

DWDM (Dense Wavelength Division Multiplexing): technology permitting the transmission of a large number of frequencies on the same fiber strand, thereby significantly increasing the bandwidth capacity of the optical fiber



Eligibility: A telephone line is said to be "eligible" for ADSL when the technical characteristics of the line in terms of signal loss are such that xDSL type technologies can be used. The length and diameter of the copper pairs (local loop) are the main parameters determining eligibility. As the technology stands at present, the subscriber's socket must not be more than 4 km from the DSLAM in order for a 512 kbits per second Internet connection to be possible.



Firewall: hardware or software device which controls access to all the computers on a network from a single point of entry. The main function of the firewall is to filter the information packets transmitted between the protected network and outside networks. In addition, a firewall can be used to perform advanced security functions such as virus detection, IP address masking on the protected network or the encryption tunnels establishment associated with authentication processes.

Full unbundling: Full unbundling consists of allowing a third party operator to control the entire local loop (both low and high frequencies).


IEEE 802.11a and 802.11b standards: radio-telecommunications standards established by the IEEE (Institute of Electrical and Electronic Engineers) describing the characteristics of wireless networks using the 5 GHz and 2.4 GHz frequency bands, respectively. (See also "RLAN – Radio Local Area Network" and "WLAN – Wireless Local Area Network").

Interconnection: the term interconnection refers to the reciprocal services provided by two operators of networks open to the public permitting all of their users to communicate freely with one another, no matter the type of network or services they use. The term also refers to the provision to a public telephone service provider of access to a public network operator's network. The objective of interconnection is to allow the subscribers of a given operator to make telephone calls to the subscribers of all other interconnected operators. Interconnection between the incumbent operator (France Télécom) and third party operators is governed by the provisions of the French Post and Telecommunications Code and is regulated by the ART.

Internet Service Provider (ISP): organization or a company providing its customers with access to the Internet.

IP address: The IP address allows a router using TCP/IP protocol to identify the unique network interface of a machine connected to the Internet. In order to be accessible or to send information over the Internet, a machine must have a public IP address, i.e. a address that is known on the Internet. ICANN has overall responsibility for managing IP addressing on a worldwide basis, but delegates responsibility for certain areas to regional and local organizations. An IP address is a sequence of 32 binary digits (see also "bit") grouped into four bytes in the form A.B.C.D where A, B, C and D are numbers between 0 and 255 (this structure corresponds to version 4 of the IP protocol, or IPv4). The problem of limited addressing resources highlighted by the growth of the Internet has led to the development of a new version of the IP protocol (IPv6), based on 128 binary elements, which will gradually be brought into use.

IP (Internet Protocol): telecommunications protocol used on the networks supporting the Internet which divides the information to be transmitted into packets, addresses the various packets, transports them independently of one another and, finally, recreates the initial message once the packets reach their destination. This protocol uses a technique known as packet switching. On the Internet, it is associated with a data transmission control protocol (TCP), hence the term TCP/IP protocol.

IRU (Indefeasible Right of Use): special type of agreement, peculiar to the telecommunications sector, for the provision of optical fibers (or transmission capacity) over a long period.



L. 33-1 license: this license, governed by Article L. 33-1 of the French Post and Telecommunications Code is the authorization held by an operator of a telecommunications network open to the public.

L. 34-1 license: this license, governed by Article L. 33-1 of the French Post and Telecommunications Code, is the authorization held by an enterprise providing public telephone service.

Linux: Linux is a multi-task and multi-user UNIX (Uniplexed Information and Computer Service) operating system. It is a so-called "open" software system, i.e., it is freely available in the source code form and modifiable under the terms of a General Public License (GNU).

Local concentrator: active telecommunications equipment connected to both the digital local exchange and the copper pairs comprising the local loop. This is the primary active equipment in the France Télécom network. The function of the local concentrator is to group several subscriber lines into one cable.

Local loop: physical circuit of the telephone network which connects the termination point of the network on the subscriber's premises (i.e., the subscriber's telephone socket) and the local loop operator's main distribution frame (generally France Télécom's primary telephone exchange) which contains a digital switch. The local loop is composed of a pair of braided copper wires.


Main distribution frame (MDF): device which establishes a temporary connection between a copper pair (local loop) and any active equipment on the operator's network. It is a vital point of flexibility in the operation of a telecommunications network.

Modem (modulator-demodulator): device transforming analogue signals into digital signals and vice versa. This equipment is necessary for connecting to the Internet (where the data exchanged are digital data).

MPEG2: video signal compression standard, used mainly for DVDs.

Multicast: routing system minimizing the number of data flows from a server to various customers by multiplying the data flows only when they are as close as possible to the destination terminals (the subscribers' copper pairs).

Multiplexing: technique permitting several communication flows to pass through the same channel/transmission bearer. Multiplexing can work in different ways: frequency multiplexing uses different frequencies for the various communications, while time division multiplexing allocates a period of time (known as a slot) to each communication.


Narrowband (also dial-up): historically this corresponds to the bit rate of a conventional telephone line using the voice frequency spectrum. By way of example, an Internet connection using a conventional telephone line is established at a maximum download rate of 56 kbits per second. See also "bit rate".

Net adds consists of the difference between Total ADSL Subscribers at the end of two different periods.


Optical fiber: transmission medium which routes digital data in the form of modulated pulses of light. It consists of an extremely thin glass cylinder (the core strand) surrounded by a concentric layer of glass (the sheath). The potential bandwidth that can be passed through an optical fiber in conjunction with the corresponding active equipment is tremendous.



Partial unbundling: partial unbundling involves providing an operator with access to the France Télécom local loop and allowing the oeprator to use the high (non-voice) frequencies of the cooper pair frequency spectrum. France Télécom continues to use the local loop in order to provide conventional telephone service to the public (using the low frequencies of the local loop). Customers continue to pay the telephone line rental to France Télécom.

Peering: type of interconnection agreement between two IP backbone networks (called peer networks) for the exchange of Internet traffic destined for their respective networks free of charge. These reciprocal exchanges take place at exchange nodes called peering points.

Ping: Ping is an acronym for Packet Internet Groper, and is a component of the Internet connection protocol which verifies the connections established on the Internet between one or more remote hosts and measures the time the data packets require to be transmitted to one computer connected to the Internet and back again. The lower the ping value (i.e., the nearer to zero) the better the network connection.

POP (Point of Presence): operator's physical site from which the operator can use an interconnection link to connect to the interconnect point of another operator (whether another POP or, in the case of France Télécom, a digital main switching unit or a digital local exchange). The POP is located on the operator's network backbone. See also "digital main switching point".

Portability: possibility for a subscriber to keep his or her telephone number when changing operators and/or geographical location.

Preselection: carrier selection mechanism allowing a subscriber automatically to route all eligible calls (local, national, international, and calls to mobile phones) so that they are carried by the operator of the subscriber's choice, without having to dial a special prefix.

Primary digital block (E1): basic unit of measurement of the capacity of interconnection links to the France Télécom network (telephone traffic and dial-up Internet traffic). It corresponds to a grouping of several communications on the same physical support structure (31 simultaneous communications, i.e. a capacity of 2 Mbits per second).

PSTN (Public switched telephone network): conventional telephone network which uses switching (a non-permanent link established by obtaining the line and then dialing). Each call established on the PSTN ties up network resources.


Reference Interconnect Offer: document describing the technical and pricing terms of France Télécom's interconnect offer (or the interconnect offer of any other operator designated as having significant market power pursuant to Article L. 36-7 of the French Post and Telecommunications Code). It allows third party operators to know what interconnection services are available and sets out the prices and the technical terms of these services.

Reverse look-up directory: service allowing users to retrieve the name and address of the owner of a telephone line on the basis of a search of a telephone number.

RLAN (Radio Local Area Network): wireless network. RLANs generally employ IEEE 802.11 standards.



SMS (Short Message Services): short digital text messages.

Source code: list of instructions in a computer program in a language capable of being understood by human beings.

Spamming: the bulk mailing of unsolicited electronic messages. These types of messages are generally sent to email lists obtained illegally (for example, through the use of a search engine on public websites or through the sale of email address files without the permission of the owners of such addresses).

Switch: equipment which routes calls to their destinations by establishing a temporary link between two circuits on a telecommunications network (or occasionally by routing information organized into packets). Switches are organized in a hierarchical fashion, i.e. the higher the position they occupy in the hierarchy, the more subscribers they serve.


Total ADSL Subscribers at the end of a period consists of the total number of customers identified by their individual “phone lines” who have signed up for Free ADSL service excluding those for whom an unsubscription notice has been registered.

TLD (Top Level Domain): the top level domain name classification, corresponding to a geographical area or a sector of activity, such as .com, .org or .fr.

Trunk exchange (TX): telephone network switch linking together the digital local exchanges. The France Télécom network is organized in a hierarchical fashion, with the trunk exchange being the highest level in the hierarchy of national exchanges. Through the digital local exchanges, the trunk exchange serves all subscribers in a given geographical area called a trunk exchange area. See also "trunk exchange area".

Trunk exchange area: the geographical area covered by a trunk exchange. France Télécom's switched network in metropolitan France is divided into 18 trunk exchange areas, defined by France Télécom in its Reference Interconnect Offer and generally corresponding to the administrative regional divisions of France. See also "Digital local exchange (LX)".



Unbundled subscribers are ADSL subscribers who have signed up for Free ADSL service on a Central Office unbundled by Free.

Unbundling: operation involving the separation of a range of telecommunications services into several distinct units. Unbundling of the local loop (or unbundled access to France Télécom's local network) consists of separating the access services provided over the local loop, mainly by separating the high frequencies from the low frequencies of the access network which constitutes the local loop, allowing new operators to use the local network of the incumbent operator in order to provide services directly to their subscribers.

Universal service: the main element of the public telecommunications service as defined by law, with the purpose of providing high quality telephone service to all at an affordable price.

Urban area: in the architecture of the France Télécom network, Ile-de-France is divided into two trunk exchange areas. The urban area corresponds to the former Seine département (Paris, Hauts-de-Seine, Seine-Saint-Denis, Val de Marne) and the peripheral area covering the Seine-et-Marne, Essonne, Yvelines and Val d'Oise départements.



VoDSL (Voice over DSL): transmission of voice traffic (in packets) using ADSL technology, i.e., using the high frequencies of the local loop, as compared to conventional telephony which uses the low frequencies of the local loop.




WLAN (Wireless Local Area Network): a network using radio telecommunications (wireless network). RLANs (see "RLAN – Radio Local Area Network") are a s

pecific type of WLAN.



xDSL (x Digital Subscriber Line): the family of technologies used to transmit digital data over the copper pair (local loop) at high speeds (e.g.: ADSL, SDSL, VDSL, etc.). See also "ADSL".