[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

EP0577804A1 - Speech/signalling overlay - Google Patents

Speech/signalling overlay

Info

Publication number
EP0577804A1
EP0577804A1 EP19930902452 EP93902452A EP0577804A1 EP 0577804 A1 EP0577804 A1 EP 0577804A1 EP 19930902452 EP19930902452 EP 19930902452 EP 93902452 A EP93902452 A EP 93902452A EP 0577804 A1 EP0577804 A1 EP 0577804A1
Authority
EP
European Patent Office
Prior art keywords
network
signalling
information
transmission
private
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19930902452
Other languages
German (de)
French (fr)
Inventor
Mark Timothy Trought
John Elwell
Ian Spiers
Markku Korpi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GPT Ltd
Plessey Telecommunications Ltd
Original Assignee
GPT Ltd
Plessey Telecommunications Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GPT Ltd, Plessey Telecommunications Ltd filed Critical GPT Ltd
Publication of EP0577804A1 publication Critical patent/EP0577804A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/58—Arrangements providing connection between main exchange and sub-exchange or satellite
    • H04Q3/62—Arrangements providing connection between main exchange and sub-exchange or satellite for connecting to private branch exchanges
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/0016—Arrangements providing connection between exchanges
    • H04Q3/0025—Provisions for signalling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/0016—Arrangements providing connection between exchanges
    • H04Q3/0029—Provisions for intelligent networking
    • H04Q3/0045—Provisions for intelligent networking involving hybrid, i.e. a mixture of public and private, or multi-vendor systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M7/00—Arrangements for interconnection between switching centres
    • H04M7/009—Arrangements for interconnection between switching centres in systems involving PBX or KTS networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13176—Common channel signaling, CCS7
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/1322—PBX
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13296—Packet switching, X.25, frame relay
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13384—Inter-PBX traffic, PBX networks, e.g. corporate networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13395—Permanent channel, leased line
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13527—Indexing scheme relating to selecting arrangements in general and for multiplex systems protocols - X.25, TCAP etc.
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13533—Indexing scheme relating to selecting arrangements in general and for multiplex systems multivendor and hybrid, e.g. public/private, networks, inc. international

Definitions

  • the present invention relates to the provision of interconnections between private networks using the facilities of public networks.
  • the PABX takes on the responsibility for establishing the connections across the pubic network based upon the routing information and, because the public network is not capable of supporting the full range of signalling required to provide the private network services, signalling for the services takes place directly between the PABXs across some other network.
  • a private telecommunications network including an interworking unit for use in interconnecting network to a further private network via a public network using separate signalling and transmission network bearers, the interworking unit comprising an encoder to take the information from the outgoing user side and encode it so that the transmission and signalling information can be carried across separate network and signalling bearers to be decoded at the further private network and a decoder to take incoming transmission and signalling information and using information provided by an encoder correlate the transmission bearers and the signalling information at the interface on the incoming user side.
  • Figure 1 shows a diagrammatic view of an interconnection between two private networks via a public network using the present invention
  • Figure 2 shows the use of the present invention in conjunction with an intelligent network
  • FIG 3 shows a flow chart of the call set up procedure using an intelligent network as shown in Figure 2;
  • Figure 4 shows a diagrammatic representation of the use of the present invention in international communications
  • Figure 5 shows a diagrammatic view of the functioning of Interworking Unit in accordance with the present invention.
  • the interworking unit sits alongside the PABX, providing a virtual network to the PABX. All private network calls route through the IWU which uses a database to translate the incomi Private network number to a public network number and establishes a outgoing call to that public network address across another private interface.
  • the signalling necessary to establish the final part of t call on the other side of the network is sent through the overlay network, the suggestion in this case is that the signalling should X.25 and calls established within the X.25 network as required to support the private network.
  • the signalling between the IWU and the PABX is a single protocol. Wher different protocols are used on the originating and terminating PABXs, protocol conversion will be required.
  • This IWU can be seen as the first of a family of products
  • Speech compression allowing multiple connections to be ma through one bearer across the network
  • X.25 as the protocol between the networks means that all existing public networks can be accessed, all that has to be managed is the relationship between the calling and called sides of the connection across the network to ensure that security is maintained.
  • FIG. 2 is shown the situation where the signalling is routed via the Service Control Point (SCP) of an Intelligent Network.
  • SCP Service Control Point
  • This enables access to services which may be provided by the Intelligent Network, one or more PBX's being connected to a gateway PBX for the network.
  • FIG. 3 shows the flow diagram for the establishment of a call using an Intelligent Network.
  • the abbreviations used are :-
  • CALL INF - Call Information Figure 4 shows the use of the invention including the use of Intelligent Networks, SYS X being the protocol used in the UK and EWSD the protocol used in USA and Germany.
  • FIG. 5 shows the construction of an Interworking Unit (IWU) for use with the invention.
  • IWU Interworking Unit
  • a prime function of the IWU is to convert the signalling protocols between the originating PBX and the terminting PBX based upon information held within the database. The following conversions are needed:
  • the PBX to IWU and IWU to PBX protocols are a choice from CorNet-N, DPNSS, QSIG (or the ISO equivalent), but other protocols can be accommodated within the concept.
  • the Encoder Function takes the information from the outgoing user side and encodes it so that the transmission and signalling can be carried across separate networks and decoded;
  • the Decoder Function takes incoming independent transmission and signalling information and, using information provided by the Encoder correlates the transmission bearers and the signalling information at the interface on the incoming user side;
  • the Splitter separates the signalling and transmission paths at the incoming user side
  • the Compressor compresses the information from a number of user side transmission bearers onto a single network side transmission channel if appropriate;
  • the Router takes the address information in the User Side signalling and generates the Network Side address to be used in the transmission network by examining database information;
  • the Outgoing Correlator adds unambiguous information to the Network Sidesignalling so that the user side signalling can be identified at the destination;
  • the Outgoing Network Interface Originates the Network Side and adds dialing functions to address the destination IWU and switches the bearers from the compressor to free network bearers;
  • the Outgoing Signalling Interface connects the Network Side signalling to the network for the destination IWU;
  • the Incoming Network Interface Terminates the Network side and flags the source to the incoming correlator
  • the Incoming Signalling Interface terminates the signalling network and provides the information to the incoming correlator and the combination processor;
  • the Incoming Correlator identifies the signalling information and incoming transmission bearer and links them together;
  • the Expander extracts the informaton from the network side transmission bearer and generates a number of user side trans ission bearers if appropriate and identifies the information to the Incoming Correlator;
  • the Combination processor takes the incoming transmission connection from the Expander Interface and combines it with the correlated signalling from the incoming signalling interface;
  • the User Side Addresser takes the address information from the Combination Processor to provide the incoming user address.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Telephonic Communication Services (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

Lorsqu'il est nécessaire de connecter des réseaux privés (PABX) entre eux, on peut effectuer cette liaison en séparant les porteuses des réseaux de transmission et de signalisation et en utilisant le réseau public. Une unité d'interfonctionnement sert à fournier les modifications de protocole nécessaires entre les réseaux privés (PABX) et publics. La signalisation peut être envoyée par des services tels qu'un commutateur de paquets X.25 ou grâce aux dispositifs d'un réseau intelligent.When it is necessary to connect private networks (PABX) between them, this connection can be made by separating the carriers from the transmission and signaling networks and by using the public network. An interworking unit is used to provide the necessary protocol changes between the private (PABX) and public networks. Signaling can be sent by services such as an X.25 packet switch or by devices on an intelligent network.

Description

SPEECH/SIGNALLING OVERLAY
The present invention relates to the provision of interconnections between private networks using the facilities of public networks.
The development of private networks is moving forward rapidly. In highly developed countries (such as the UK), dedicated private networks are now commonplace, linking together the relatively large sites of a particular business.
In the UK, the next development is towards the "Integrated Scenario" where the public network co-operates with the private network signalling protocols to provide "Virtual Private Circuits" with channels in a 2048kbit/sec bearer switched to different locations based upon the signalling information.
Other countries have not been so liberal with the use of dedicated private circuits and networks have not evolved in the same way and the public network operator sees less benefit in co-operating with the private networks.
In these countries, an alternative strategy is developing known as the "Overlay Scenario". In this case, the PABX takes on the responsibility for establishing the connections across the pubic network based upon the routing information and, because the public network is not capable of supporting the full range of signalling required to provide the private network services, signalling for the services takes place directly between the PABXs across some other network.
To achieve this with existing PABXs with their dedicated protocols would require a significant change to the signalling protocols and call establishment logic.
An alternative approach is to provide an "Overlay Scenario Interworking Unit". The purpose of this unit would be to "fool" the PBX into thinking that it was permanently connected to dedicated private circuits, whilst dynamically establishing the connections across the public network as they were required.
According to the present invention* there is provided a method of providing system and network independent dedicated private circuit telecommunications functionality using separate signalling and transmission network bearers.
There is further provided a private telecommunications network including an interworking unit for use in interconnecting network to a further private network via a public network using separate signalling and transmission network bearers, the interworking unit comprising an encoder to take the information from the outgoing user side and encode it so that the transmission and signalling information can be carried across separate network and signalling bearers to be decoded at the further private network and a decoder to take incoming transmission and signalling information and using information provided by an encoder correlate the transmission bearers and the signalling information at the interface on the incoming user side.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which :-
Figure 1 shows a diagrammatic view of an interconnection between two private networks via a public network using the present invention;
Figure 2 shows the use of the present invention in conjunction with an intelligent network;
Figure 3 shows a flow chart of the call set up procedure using an intelligent network as shown in Figure 2;
Figure 4 shows a diagrammatic representation of the use of the present invention in international communications; Figure 5 shows a diagrammatic view of the functioning of Interworking Unit in accordance with the present invention.
There are a number of options as to how an interworking unit may be achieved, but Figure 1 shows one possibility.
The interworking unit (IWU) sits alongside the PABX, providing a virtual network to the PABX. All private network calls route through the IWU which uses a database to translate the incomi Private network number to a public network number and establishes a outgoing call to that public network address across another private interface.
This is routed back through the PABX so that' the public network interfaces that are required on the PABX can be used, simplifying the development of the IWU. The address provided on th secondary call identifies the call, but need not route the call to the final extension across the public network.
The signalling necessary to establish the final part of t call on the other side of the network is sent through the overlay network, the suggestion in this case is that the signalling should X.25 and calls established within the X.25 network as required to support the private network.
Because the IWU is connected only to a single PABX, the signalling between the IWU and the PABX is a single protocol. Wher different protocols are used on the originating and terminating PABXs, protocol conversion will be required.
This IWU can be seen as the first of a family of products
1. Simple DPNSS - DPNSS across the network;
2. Simple CorNet-N - CorNet-N across the network;
3. CorNet-N - DPNSS Interworking across the network;
4. CorNet-N or DPNSS - QSIG across the network;
5. Speech compression allowing multiple connections to be ma through one bearer across the network;
6. Dynamic establishment of the signalling bearer to cost reduce the calls;
Other unrelated functions may also be able to be added to the IWU in the future.
Using X.25 as the protocol between the networks means that all existing public networks can be accessed, all that has to be managed is the relationship between the calling and called sides of the connection across the network to ensure that security is maintained.
Initially, it can be expected that the IWU will manage the virtual network database, but there is no reason why other databases should not be used.
This example has several benefits:-
1. It builds upon strengths in networking;
2. It is not "core product" in that it is an external add-on to any product;
The solution is not "the cheapest" for the customer in that it requires him to have additional private network interfaces and generates additional traffic within the gateway PABXs. However, if it proves successful, the logic could be incorporated into the core product in the future.
In Figure 2 is shown the situation where the signalling is routed via the Service Control Point (SCP) of an Intelligent Network. This enables access to services which may be provided by the Intelligent Network, one or more PBX's being connected to a gateway PBX for the network.
Figure 3 shows the flow diagram for the establishment of a call using an Intelligent Network. The abbreviations used are :-
SETUP DN - Setup Dialled Number
REQ TR - Request Transmission
RES NDN - Reserve Network Dialling Number
SETUP IDN - Setup Incoming Dialling Number
EST AP-AP DIALOG - Establish Application-Application
Dialog
CALL INF - Call Information Figure 4 shows the use of the invention including the use of Intelligent Networks, SYS X being the protocol used in the UK and EWSD the protocol used in USA and Germany.
Figure 5 shows the construction of an Interworking Unit (IWU) for use with the invention.
A prime function of the IWU is to convert the signalling protocols between the originating PBX and the terminting PBX based upon information held within the database. The following conversions are needed:
1. Conversion between the PBX to IWU protocol and the Network Access protocol;
2. Conversion between the Network Access protocol and the IWU to PBX protocol;
3. Conversion between the PBX to IWU protocol and the IWU to IWU protocol;
4. Conversion between the IWU to IWU protocol and the IWU to PBX protocol.
The PBX to IWU and IWU to PBX protocols are a choice from CorNet-N, DPNSS, QSIG (or the ISO equivalent), but other protocols can be accommodated within the concept.
Within the IWU the follow functions are carried out:-
The Encoder Function takes the information from the outgoing user side and encodes it so that the transmission and signalling can be carried across separate networks and decoded;
The Decoder Function takes incoming independent transmission and signalling information and, using information provided by the Encoder correlates the transmission bearers and the signalling information at the interface on the incoming user side;
The Splitter separates the signalling and transmission paths at the incoming user side;
The Compressor compresses the information from a number of user side transmission bearers onto a single network side transmission channel if appropriate;
The Router takes the address information in the User Side signalling and generates the Network Side address to be used in the transmission network by examining database information;
The Outgoing Correlator adds unambiguous information to the Network Sidesignalling so that the user side signalling can be identified at the destination;
The Outgoing Network Interface Originates the Network Side and adds dialing functions to address the destination IWU and switches the bearers from the compressor to free network bearers;
The Outgoing Signalling Interface connects the Network Side signalling to the network for the destination IWU;
The Incoming Network Interface Terminates the Network side and flags the source to the incoming correlator;
The Incoming Signalling Interface terminates the signalling network and provides the information to the incoming correlator and the combination processor;
The Incoming Correlator identifies the signalling information and incoming transmission bearer and links them together;
The Expander extracts the informaton from the network side transmission bearer and generates a number of user side trans ission bearers if appropriate and identifies the information to the Incoming Correlator;
The Combination processor takes the incoming transmission connection from the Expander Interface and combines it with the correlated signalling from the incoming signalling interface;
The User Side Addresser takes the address information from the Combination Processor to provide the incoming user address.

Claims

1. A method of providing system and network independent dedicated private circuit telecommunications functionality using separate signalling and transmission network bearers.
2. A method as claimed in Claim 1 further including the use of a data base to determine the routing across intervening switched and fixed networks to provide private network capabilities.
3. A method as claimed in Claim 1 or 2, further including the compression of the user information before transmission.
4. A method as claimed in Claim 1, 2 or 3 wherein the signalling network bearer is part of an X.25 packet switching network.
5. A private telecommunications network including an interworking unit for use in interconnecting the network to a further private network via a public network using separate signalling and transmission network bearers, the interworking unit comprising an encoder to take the information from the outgoing user side and encode it so that the transmission and signalling information can be carried across separate network and signalling bearers to be decoded at the further private network and a decoder to take incoming transmission and signalling information and using information provided by an encoder correlate the transmission bearers and the signalling information at the interface on the incoming user side.
6. A network as claimed in Claim 5, the encoder comprising a router to take the address information in the user side signalling and generate therefrom using information contained within a database a network side address to be used in the transmission network.
7. A network as claimed in Cl im 6, the decoder comprising a correlator to add unambiguous information to the network side signalling so that the user side signalling can be identified at the destination.
8. A network as claimed in Claim 5, 6 or 7 the encoder further comprising a compressor and the decoder further comprising an expander.
EP19930902452 1992-01-24 1993-01-25 Speech/signalling overlay Withdrawn EP0577804A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9201540 1992-01-24
GB929201540A GB9201540D0 (en) 1992-01-24 1992-01-24 Speech/signalling overlay

Publications (1)

Publication Number Publication Date
EP0577804A1 true EP0577804A1 (en) 1994-01-12

Family

ID=10709188

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930902452 Withdrawn EP0577804A1 (en) 1992-01-24 1993-01-25 Speech/signalling overlay

Country Status (3)

Country Link
EP (1) EP0577804A1 (en)
GB (1) GB9201540D0 (en)
WO (1) WO1993015583A1 (en)

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2704378B1 (en) * 1993-04-21 1995-06-30 Dassault Automatismes Telecomm Telephone installation with reduced speed digital transmission line.
BE1007360A3 (en) * 1993-07-28 1995-05-23 Atea Nv Device for communication between PRIVATE TELEPHONE AND THUS USED EMULATOR.
GB9408798D0 (en) * 1994-05-04 1994-06-22 Plessey Telecomm Connectionless information service delivery
US5517564A (en) * 1994-07-29 1996-05-14 British Telecommunications Public Limited Company Communication apparatus and method
US6205216B1 (en) 1994-07-29 2001-03-20 British Telecommunications Public Limited Company Apparatus and method for inter-network communication
GB2297882A (en) * 1995-02-10 1996-08-14 Northern Telecom Ltd Telecommunications system
DE19527815C1 (en) * 1995-07-28 1996-10-17 Siemens Ag Mobile network emulator for private communication terminals
NL1001458C2 (en) * 1995-10-20 1997-04-22 Nederland Ptt System for signal transmission between business centers.
US5661790A (en) * 1995-11-03 1997-08-26 Ericsson, Inc. Call back service for a regulatory restrictive area
US5793771A (en) * 1996-06-27 1998-08-11 Mci Communications Corporation Communication gateway
SE517557C2 (en) * 1996-08-06 2002-06-18 Ericsson Telefon Ab L M Method and apparatus for interconnecting two associated gear units
US5805690A (en) * 1996-10-07 1998-09-08 Timeplex, Inc. Method of distributed call control in a distributed transit PBX system
US5903571A (en) * 1996-10-07 1999-05-11 Timeplex, Inc. Distributed transit private branch exchange
GB2318701A (en) * 1996-10-26 1998-04-29 Ibm Intelligent network protocol gateway
WO1998021904A1 (en) * 1996-11-11 1998-05-22 British Telecommunications Public Limited Company Telecommunications networks
NL1005178C2 (en) * 1997-02-04 1998-08-06 Koninkl Kpn Nv Remote access system.
AU740308B2 (en) * 1997-03-31 2001-11-01 Telefonaktiebolaget Lm Ericsson (Publ) Interconnection of telephone exchanges via a computer network
US6081591A (en) * 1997-04-16 2000-06-27 Skoog; Frederick H. Signaling network gateway device and method for use in a signaling network
DE19752607B4 (en) * 1997-11-27 2004-09-16 Siemens Ag Method and device for exchanging application-specific data between an intelligent network and data-capable end devices
WO2001017211A2 (en) * 1999-08-31 2001-03-08 Siemens Aktiengesellschaft Communications system
FI109320B (en) * 1999-11-02 2002-06-28 Nokia Corp A signaling

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2125252B (en) * 1982-07-27 1985-08-29 Standard Telephones Cables Ltd Telecommunication exchange network
GB2174269B (en) * 1985-04-20 1988-09-07 Stc Plc Private automatic branch telecommunication exchange
US4924500A (en) * 1989-05-17 1990-05-08 Northern Telecom Limited Carrier independent network services

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9315583A1 *

Also Published As

Publication number Publication date
GB9201540D0 (en) 1992-03-11
WO1993015583A1 (en) 1993-08-05

Similar Documents

Publication Publication Date Title
EP0577804A1 (en) Speech/signalling overlay
US5818921A (en) Signaling system and method for enabling PBX-PBX feature transparency across a switched public network
US5850434A (en) Telecommunications network
FI114181B (en) A method, system, and apparatus for controlling communications
US5710769A (en) Merging the functions of switching and cross connect in telecommunications networks
EP0398183B1 (en) Carrier independent network services
US5583929A (en) Customer oriented telecommunications network
EP0772941B9 (en) Communication apparatus and method
EP0711052B1 (en) Improvements in or relating to telecommunication systems
KR19980086939A (en) Class of Service Auto Routing
US6711252B2 (en) Method and system for implementing intermediary services in a telecommunication system
US6882721B2 (en) Method and apparatus enabling local number portability in telephone networks
US5903571A (en) Distributed transit private branch exchange
EP1205079B1 (en) Method and system for signaling in a telecommunication system
US20010053218A1 (en) Transaction bridging/forwarding in signaling system of telecommunications network
US5917901A (en) Telecommunications system
US5644632A (en) Distributed key telephone station network
US6160882A (en) Subscriber access network, exchange, service control point, and method of establishing a connection
CA2233125C (en) Method and apparatus for providing multi-network virtual services
US6205216B1 (en) Apparatus and method for inter-network communication
Cisco Intelligent Network Server
US5608790A (en) Trunk utilization in a telecommunications network
EP0748133B1 (en) Method for operating a telecommunications network and associated network
GB2185657A (en) Automatic telecommunication system
JPH1188500A (en) Method for establishing connection, exchange and communication network

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19930922

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): CH DE ES FR GB IT LI NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19960120