MXPA99005645A - Atm network providing transparently narrowband based telephony services without requiring atm-switching - Google Patents

Abstract

Narrowband based telephony services and associated value added services are provided transparently in a network providing ATM switching and no STM switching is required in an ATM network (625) to which units (601, 603) requiring such services are connected. This is obtained by means of, when a call enters the ATM network (625), first finding the output port (619) from the ATM network (625), then returning the address of that port to the entry port (617) and thereafter ATM switch the connection directly through the ATM network (625). Hereby bandwidth resources are more efficiently used since all switching is done by ATM regardless of application. Heavy investments in providing intelligent services support by existing systems can be reused in an efficient way and thus reduce time to market for the introduction of the value added services.

Description

"ATM NETWORK THAT PROVIDES TRANSPARENTLY BROADBAND BASED TELEPHONE SERVICES WITHOUT REQUIRING SWITCHING ATM " TECHNICAL FIELD The present invention relates to a method and system for switching calls in an Asynchronous Transfer Mode (ATM) network.

PREVIOUS TECHNICAL AND TECHNICAL BACKGROUND The telecommunication and data communication networks are currently constructed as separate superjacent networks. The result is that the transport and switching for the data belonging to different applications are carried out in a separate equipment, eg, frame Relay switches and networks for a LAN interconnection traffic type with LAN and PSTN switches / ISDN and networks for voice traffic. With the introduction of ATM, a common switching network for all these services is possible. This also facilitates common access for all types of traffic, e.g., data, voice and video, thereby reducing the amount of network equipment.

- However, for voice traffic, a number of supplementary services has been developed for both the end user and the service provider. These services can be selection of services for closed user groups, call distribution services, flexible fracturing mechanisms, different access methods, etc. This multitude of services is implemented in the narrowband equipment currently supporting PSTN and ISDN. When a common access point is provided, and the transport and switching function using ATM for both voice, data, and video, it has to be built to a new network that has these switching capabilities. A requirement is that a new network using ATM as the common switching method has to provide all the existing services supported by the narrowband voice network that currently operates. Neither the end user nor the service provider can be requested to drastically reduce the service content by introducing ATM. The existing solution to fill this requirement is to use ATM as the single transport mechanism. This is done by linking either point to point between the narrow band equipment such as PBXs or the access devices, or linking to a narrow band switch, see ATM Forum / 95-0446R9, Baseline Text for Voice and Telephony through ATM - ATM Link for Narrow Band Services, ATM Forum, August 1996. Thus, for example in Figure 1, show two different narrow band equipment 101 and 103 that communicate, at least partially, through an ATM network 105 to which a narrowband switch 107 is also connected. The narrow band switch for example may be an AX switch manufactured by the Ericsson company. In the figure, interfaces A are existing narrow band trunks comprising voice circuits and signal sending capabilities. Line I illustrates a point-to-point link of the full narrowband trunk between the two narrowband equipment and the connections that provide capabilities to provide telephony services with ATM transport, but not switching. The problems associated with the existing solutions are: i) The link for trunks from point to point (I) generally requires a mesh network, that is, in order to interconnect the narrowband equipment N / network access points, trunks of N (N-l) / 2 are required through the ATM network. ii) The link to a narrowband switch still requires that all voice traffic be switched in the STM (Synchronous Transfer Mode) in the narrowband switch, and the ATM switching capabilities are not used. An extra STM-ATM transition also introduces delays that must be retracted, or an affected voice quality will have to be accepted. iii) There will be a waste of resources in the ATM network, the capabilities of which are not fully used. A description of the way in which this is proposed to be implemented in the network is provided through ATM Forum either in the Voice and Telephony group through ATM (VTOA). Also the international patent application WO / 97 09807, describes a system for providing virtual connections through an intermixing multiplexer in a call by means of a call base. The system uses established ATM connections.

COMPENDIUM It is an object of the present invention to provide a system and method for enabling the ATM network to be used in a more efficient manner and through - of which the problems can be overcome as indicated in the foregoing. This object and others are obtained using ATM as the mechanism is switched and at the same time providing all added telephony services of existing value to an ATM-based network. This can be achieved by providing logical units connected between the ATM network and the existing narrowband switches and providing the terminals at the interface between the STM network and the ATM network with certain additional logical functions by means of which they can interact with the logical units connected to the narrowband switches. The logical units are used to identify the output port from the ATM network with which a call going into the ATM network is to be switched. This is done by using the information and logic contained in the narrowband switches. The address of the exit port is then returned to the port of entry by means of a special protocol. All traffic is then directed directly to the port of exit of the port of entry through the ATM network. During transport through the ATM network, the logical unit emulates a virtual connection that is provided to the narrowband switches. When the - connection, this is perceived by the logical units that in turn release the emulated virtual connection that is seen through the narrowband switch. During the existence of a connection, the call is completely controlled by the narrowband switches. There are several advantages associated with this method compared to those existing. Therefore, narrow-band-based telephony services and associated value-added services are transparently provided through the network that provides ATM switching and no STM switching is required. Also, network bandwidth resources are used more efficiently since all switching is carried out by ATM independently of the application. The ATM network is a switched ATM network, that is, the sending of ATM signals is used to both establish and disconnect connections through the ATM network, at any level of the ATM network, eg, AAL2 level. In addition, considerable investments to provide support of intelligent services through existing systems can be reused in a way efficient and therefore reduce the time to market for the introduction of services added to the value. The method as described provides a feasible and viable migration path for existing voice networks such as PSTN and ISDN to an ATM-based multiservice network, the implementation of the method in an ATM system provides ATM operators with only one possibility to offer a competitive service with minimal investments.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described in greater detail through non-limiting examples and with reference to the accompanying drawings: Figure 1 is an image illustrating the installation of a call connection in accordance with the prior art. Figure 2 is a schematic image illustrating the installation of a call connection using logical units or switch emulators. - Figure 3 is a general view illustrating an ATM network to which the different STM connections are connected.

- Figure 4 illustrates an example in the manner in which the emulators of the switch can be used to obtain a more efficient switching through the ATM network shown in Figure 3. - Figure 5 is a schematic diagram illustrating the flow of information during an installation sequence of call. Figure 6 is a diagram illustrating the message flow during a call installation procedure. Figure 7 is a schematic image of a switch emulator. Figures 8a to 8f are flow charts illustrating the different procedures carried out in a switch emulator. Figures 9a-9e are flow charts illustrating the different procedures carried out in a voice multiplexer attached to the same ATM network as the switch emulator of Figures 8a to 8f.

DESCRIPTION OF THE PREFERRED MODALITIES Figure 2 illustrates the separation of a call connection to a Call Services Network (CSN) 221 and a Bearer Services Network (BSN) 223. At both, an ATM network and a narrow band terminal at 203 are shown at 201, which is connected to the ATM network 201 through a broadband terminal 209. Also, a narrow band network 205 connects to the ATM network 201, through a broadband terminal 211. The narrowband switches 213 and 215 are also connected to the ATM network and the switches 213 and 215 are equipped with switch emulators 217 and 219, respectively. It should be noted that other applications, e.g., Frame Relay or Internet applications, using the same ATM switching network 201, are not included in the figure. The CSN call control procedures can be supported by any existing narrowband signal sending protocol, e.g., sending of ISDN (Q.931), Qsig, ISUP, etc. signals. These protocols are transparently carried between the narrow band entities in CSN through BSN. The call control procedures used in BSN are used for the establishment and release of resources for voice transport. These procedures can be supported by any of the existing or future protocols used for this purpose, e.g., Q.2931, P-NNI or B-ICI. The BSN call control procedures are invoked upon request through CSN. The resource control procedures are present to support a function of the switch emulator and manage resources towards access to the narrow band and trunk sides. The narrow band terminal (TE) 203 may be a PBX or a PSTN / ISDN access stage, e.g., remote subscriber stage. The narrowband network 205 can be any existing network such as ISDN or PSTN. The broadband terminals (B-TE) 209 and 211 handle the intermixing of the voice transport circuits to the ATM transport, e.g., using AAL1, AAL2 or AAL5, depending on the selection of the ATM adaptation function. This broadband terminal functions as a terminal for the ATM network. Therefore, it can be connected with either a narrowband terminal for example the terminal 203, or a network, for example the network 205. In Figure 3, a network is shown comprising both the STM part 301 and the 303 ATM. Also shown are the broadband terminals (B-TEs) 305, described above in conjunction with Figure 2, and the interface between the 301 part of STM and the 303 part of ATM, the narrowband terminals (TEs). 307, the ISDN 309 connections and the ATM switches 311 forming an ATM switching network 201 in Figure 2. The ATM switches 311 therefore connect to each other. Some ATM switches only connect to other ATM switches while others, at the edge of the ATM network, also connect to broadband terminals 305. A broadband terminal 305 is connected to an ATM switch 311 and to devices outside the ATM network, e.g., with an ISDN connection 309 and a multitude of narrowband terminals 307. In Figure 4, which has the same reference numbers as in Figure 3, but increased by 100, the considerable portion of the ATM network is divided into four different switching domains 421, 423, 425 and 427 equipped with an emulator of the switch (SE) each, shown at 429, 431, 433 and 435 respectively and connected to an ATM switch -in the respective domain. All the SEs in turn are connected with a narrow band switch (not shown) each. The narrowband switches are responsible for the switching in their switching domains 421, 423, 425 and 427, respectively. The switch emulators 429, 431, 433 and 435 are preferably co-positioned with their corresponding narrow band switches (not shown).

- - The operation of the network in Figure 2 will now be described as an example where the bearer service network is provided in Figures 3 and 4. Therefore, if a voice path 207 is to be established between the terminal 203 of narrow band and narrowband network 205 through the ATM network 201, the switch emulator or the logic unit 217 emulates a STM switch towards the narrow band call control and a virtual connection is established. The narrow band call procedures require that the STM resources be reserved in the ATM network 201 for voice support. The emulators of the switch 217, 219 provide emulation of these resources towards the logic of the narrowband switch in the switches 213 and 215. The actual voice transport therefore does not pass through any STM switching function and is switched over. a call-by-call basis on request only in the ATM network. The switch emulator handles resource control as described above for accesses and trunks and uses ATM for transport. An example of resource control, i.e., accesses and trunks, which are carried out by the switch emulator 217, is provided in Figures 3 and 4. Each of the switch emulators 217 and 219 manages a number of accesses to the TE and narrowband networks. Each switch emulator also handles a number of Virtual Trunks (VTs) between the emulators of the switch. The virtual trunk is introduced to reflect the possible routes that must be taken in the CSN and has no physical duplicate in the current BSN. The access and trunks are defined in the same way as in the existing narrow band switches. The virtual nature of the trunks is hidden from the logical functions of the narrowband switch. In Figure 4, four SEs are indicated, and also four VTs between these SEs. As an example, consider a call that extends between access points Al2 and A45 in Figure 3, that is, between a TE and an access to ISDN. The path selected by the logical functions of the narrowband switch in this call routing function uses the VT13 path, shown in Figure 4. The logical call path traverses two logical narrowband switches (not shown), which preferably they are co-located with the CSNs 429 and 431. The routing tables are established according to the topology of the desired CSN using access addresses (Aij) and selected routes (ATkl). The routing information and the topology of the resulting CSNs are independent of the topology and structure of the underlying BSN and can be be done independently of, or part of, the BSN direction project, whichever is desired. The function of the switch emulator can be implemented in the ATM system, in the narrow band system or as a single system attached to an ATM system and the narrow band system. There are many different methods for making a call setup using the emulator (s) switch and two methods for establishing a call will now be described and explained in the following paragraphs.

Method 1: A first approach depends on the idea that all routing is carried out as much as possible in the domain of call services, and when a real voice path is required, which will request through the service network the carrier. This is a serial procedure as indicated below. The network entities to which reference is made are those of Figures 1 and 2. During the narrowband establishment, several services added to the value can be invoked before they are put in contact with the actual destination is that - - make. The sequence of events can then be as follows: 1. The narrowband terminal issues a call request to the network by sending, e.g., a message ESTABLISHED by the ISDN. This request is analyzed by the virtual switch and any service intelligence can be invoked. The addresses of the narrowband network are used to analyze the call establishment request. 2. After the routing analysis and call origination services have been handled, the call establishment request is routed to the destination, e.g. through the ISUP IAM message. 3. After the analysis and any service invocation in the next virtual switch, the exit point is determined. The Broadband Outgoing Terminal (B-TE) 211 is put on alert status of the existing call. 4. The output of B-TE 211 or the output switch emulator 219 notifies the entry of B-TE 209 of the ATM port address of the B-TE's output, e.g. returning the ATM Final System Address (AESA), together with the information identifying the specific call connection for correlation, e.g., by means of a call identifier in a data field reserved for this object. 5. The exit port address is used either to reserve a point-to-point ATM connection for a voice path between the incoming and outgoing B-TE, e.g., the path 207 shown in Figure 2, or to use an existing ATM connection. Optionally the voice path connects completely already at this point. 6. The outgoing virtual switch is notified that the voice path is established, and the termination side can be provided with the call set-up request, i.e., either reserved or connected. 7. The call setup request is passed to the narrow band terminal / network. 8. Upon receipt of a connection message from N-TE, the ATM path is completely switched on if it has not already been done under 5. above. 9. The release and disconnection procedures are carried out in parallel in both the CSN and the BSN.

Method 2: A second approach is parallel since the establishment procedure N and the establishment procedures B are initiated simultaneously. All services added to the value are invoked in the CSN as the call proceeds. At the point of destination, the two establishment procedures are mapped before the destination of the ongoing call is notified. In Figure 5, a call (voice) connection should be established in a network comprising the units of Figure 4 on a B-channel from the telephone 501 to the telephone 503, connected to the PBXs 505 and 507, different, respectively. The two PBXs 505 and 507 both connect to the same ATM network 509 through the voice multiplexers (VM) 511 and 513, respectively. The PBX 505 connects to the ATM network at a site controlled by a switch 515 and the PBX 507 connects to a site controlled by a switch 517. In addition, the logic units or switch emulators (SEs) 519 and 521 are connected at switches 515 and 517, respectively. Therefore, when a number is dialed by telephone 501, an establishment message 551 is sent to the switch controlling that part of the network, i.e. switch 515 in this case. The switch then assigns the requested B-channel in VM 511, as indicated in 553. Then, the switch 515 starts searching for the port - - of output from the ATM network 509, i.e., in this case VM 513. In this case, the switch 515 finds that the output port is located outside the control domain of the switch 515. The switch 515 requests a trunk to 517 from the unit that is in possession of the trunk, that is, SE 519 in this case. SE 519 emulates retention 555 of a trunk extending from switch 515 to the final destination. When the virtual trunk is retained, a message 557 is transmitted to the switch 517 from the switch 515 for further analysis. Thus at this point, the switch 515 has logically retained a connection between the input port on the VM 511 and the output port from the switch 515. However, this connection is only emulated by the SE 519. Then, the switch 517 receives message 557 and then retains its entry trunk at 559. The SE 521 then emulates the retention of the trunk. The switch 517 analyzes the establishment information in order to find the output port from the ATM network. The switch 517 that finds the output port instead of VM 513, retains the output port at 561, and at the same time connects the emulated connection via SE 521, which is extends from VM 511 through the emulated connection in SE 519, completely to VM 513. VM 513 then finds that the incoming call requires a real physical connection, through of the ATM network and sends a message 562 to the entry VM 511 comprising the address of the output VM 513. The entry VM 511 then establishes an ATM connection with VM 513 through the message sequence 563. The switch 517 now knows that the connection is fully established up to the output port on VM 513 and notifies the receiving PBX 507 via message 564. The voice traffic is then switched through ATM completely from VM 511 to VM 513 without STM is switched on switches 515 and 517. Switches 515 and 517 in this case, they are used only to find the VM 513, loading the call and other possible additional services. In Figure 6, another example of the manner in which a connection can be established is illustrated. The Figure shows two PBXs 601 and 603 placed in the directions controlled by switches 605 and 607, respectively. Also shown is a third transit switch 609, three switch emulators (SE) 611, 613 and 615, two voice multiplexers 617 and 619 connected with two ATM switches 621 and 623, which are part of a single ATM network 625. If a voice connection is to be established between two PBXs 601 and 603, this can be done in the following manner. First, an establishment message 1 is transmitted transparently from PBX 601 to its corresponding switch 605. The switch 605 through analysis finds that the final destination for the call is placed under another switch associated with a certain trunk. A message 2 is then sent to reserve a path between the input port 617 and the output trunk from the switch 605, whose message is intercepted by SE 611. Then, the SE 611 allows a message 3 to VM 617 to assign the resources in VM 617 for the connection to be established, and then recognizes 4 before switch 605, which is now reserving a trunk. The switch 605 begins to establish a connection by sending a message 5 to the other switch 609 signaled by the switch 605 that reports that a connection is to be established and to find the correct output address from the ATM network for the connection. The switch 609 receives the message and checks whether the requested address is controlled by the same or whether the request has to be sent. In this case, the request has to be sent and the switch 609 reserves in 6 a path between the input trunk from the switch 605 and an output trunk to the switch 607 which is signaled by the switch 609. The input and output trunks are then connected. The reservation message 6 is intercepted by SE 613 associated with the switch 609, and the SE emulates a trunk reservation and the connection is now established with the switch 609 and the switch emulator 613 by means of responding by sending a message 7. of acknowledgment informing the switch 609 that a trunk has been reserved. Since the final destination for the call was not found under switch 609, a message 8 is sent to switch 607 to establish the connection. The switch 607 receives the message 8 and finds that the final destination is controlled by the switch 607, and issues a message 9 to reserve a connection at the end terminal, ie the VM 619. The SE 615 intercepts the message 9 and sends a message 10 to VM 619 to reserve the resources in VM 619 for the connection. During the reception of the message 10, an emulated end-to-end connection is established between VM 617 and VM 619. The VM 619 determines that an actual connection is to be established through the ATM network 625, which corresponds to the emulated connection to through SE 611, 613 and 615, and answers with a request 11 containing the address of VM 619 to establish a connection, whose request is returned through messages 12, 13 and 14 to VM 617 that is connected to the PBX from which it is generated the original settlement message. Therefore, the VM 617 now has knowledge of the exit address of the ATM network to which it will direct the voice traffic. The VM 617 sends an establishment message 15 to the ATM switch to which it connects containing the address that was returned in the return messages 11, 12, 13 and 14, or uses an existing ATM connection. The figure illustrates the case when a new connection is established. The set-up message is switched in ATM through the ATM network 625 to the ATM switch 623, which is connected to the VM 619. The set-up message 16 is then sent from the ATM switch 623 to VM 619. VM 619 then recognizes the connection establishment request 10 to the SE 615 via a message 17. The SE then sends a message 18 to the switch 607 to confirm the establishment of the connection, as a response to the message 9. The switch 607 then he sent an establishment message 19 transparently to the proposed receiver in this case the PBX 603, which answers with a message 20 that answers the call request. The 607 switch receives the message 20 and request a complete connection, issuing a message 21. The full connection bi-directional request message 21 is intercepted by SE 615 which sends a message 22 to the VM 619 requesting a full bidirectional ATM connection to the VM 617 to the VM 619. Therefore, VM 619 sends the bi-directional full connection message 23 to the ATM switch 623 and returns a recognition message 24 to the SE 615. The bi-directional complete connection message 23 is sent through the ATM network 625 to the switch 621. of ATM and sends a complete connection message 32 to the VM 617. At the same time, the messages 24-31 are sent back to VM 617. Therefore, the first recognition messages 24 and 25 are returned from VM 619 to through SE 615 to switch 607. Switch 607 then begins a full backward connection to PBX 601. This is accomplished by a response message 26 to switch 609, which outputs a complete connection 27 is intercepted by SE 613, which then marks the emulated path as completely connected and returns a recognition message 28, messages 29, 30 and 31 being transmitted from switch 609 to VM 617 via switch 605 and SE 611.

After receipt of the messages 31 and 32, the VM 617 issues a recognition message 33 to the SE 611, which sends a message 34 to the switch 605 as a final acknowledgment of complete connection. Finally, switch 605 sends a connection message 35 to PBX 601. In this way a physical voice connection is established from PBX 601 to PBX 603 through VM 617, through ATM network 625, and through VM. 619, which is commuted in ATM completely through the ATM network 625. In Figure 7, the elements of, the functions carried out by and the connections fixed to the logical units or switch emulators (SE) are illustrated. Therefore, a logical unit or switch emulator 701 has input / output means 703 for communicating with a narrowband switch shown at 723 and means 705 for communicating with units set to the ATM network, shown at 721, such as, for example, voice multiplexers, etc. In addition, the unit 701 has means 707 and 711 connected to the input / output means 703 for emulating a fabric of the STM switch. The unit 701 also has a processing unit 709 including a memory for storing the information connected to the input / output means 703 and 705. The processor unit 709 controls the flow of the signal within the unit 701. The memory in the Unit 709 of the processor can be used to store information regarding connections and input transceptions. The memory can also be used for temporary or permanent storage of the information related to the ATM network in which the unit 701 is connected, and this information can be collected from the data bases used by the narrow band switch through the medium 703 of entry / exit. The processor unit 709 controls a call control unit 707, which provides the functions of providing access to the physical ports connected in the ATM network, eg, placed in the voice multiplexers, and which controls the functions in the 711 unit. On the 711 unit, switch emulation and virtual trunk functions are in place. Therefore, in the unit 711, the input ports and the output ports are associated by means of the switch emulator function and a virtual trunk is provided by the virtual trunk function. The unit 711 also handles accesses in broadband terminals, e.g., voice multiplexers, fixed to the ATM network. The access is carried out through the means 705 of entry / exit. The operation of a switch emulator (SE), is described above in conjunction with Figures 4 to 7, and will now be described by means of the flow charts in - Figures 8a to 8f. Therefore, Figure 8a is a flow chart illustrating the steps carried out in a switch emulator (SE) when a request to establish a connection is received. In this way, first, in block 800 the process is unoccupied. Then, in block 801, a message arrives from the narrow band switch with which the SE with which it is connected is associated, requesting the reservation of the input port, the output port and a connection between them. Then, in a block 803, the SE checks and determines which type of port originates in the request. If the requested source port is a real physical port, that is, an access in the voice multiplexer, the actual access branch 805 is taken and the SE reserves a physical port in that voice multiplexer in block 809. If by another part the requested port is a virtual trunk, branch 807 is taken and in block 811 the SE marks the virtual trunk or rather a virtual channel in the virtual trunk, as it has been reserved. Then, the SE identifies the type of output port in block 813. If the output port type is real access in the voice multiplexer, branch 815 is taken, and if the output port type is a trunk virtual, branch 817 is taken. If you take the branch 815, the process proceeds to block 819 where the physical termination port is reserved in the voice multiplexer. The process then continues to a block 825 where the process is marked in a state indicating that the connection is requested while being reserved. If the branch 817 is taken, the process marks the virtual trunk or rather a virtual channel in the virtual trunk, as it has been reserved, and then in a block 823, notifies the narrow band switch to which the SE is connected. , that the request received in block 801 has now been satisfied. Then, the process continues to block 825. In Figure 8b, the process is initially waiting in the state with the connection marked as reserved, ie the state of block 825. This is indicated in a block 827. It is then received another request for the establishment of a physical connection of another SE or a voice multiplexer in a block 829. The SE then determines where the request will be sent, this being carried out by means of a query box, etc., in a block 831. Next, in a block 833, the request for physical connection is sent to the next unit in the network to which the SE is fixed, in this case another SE or a voice multiplexer. Then in a block 835, the type of - - Locally controlled port transmitting in the SE is identified. If the port type is determined as being a physical port, branch 837 is taken and the process is marked in a state where the connection is marked as reserved, in a block 841. If on the other hand, the type of. termination port is determined as being a virtual trunk in block 835, branch 839 is taken and the process is marked in a state with the physical connection being initiated in a block 843. In Figure 8c, the process is initially waiting in a state where the connection is reserved, ie, block 845. A message is then received in a block 847 from a terminating voice multiplexer notifying the SE that the processing of the connection request to the SE has now been completed. side that contains the output port of the ATM network. The process then proceeds to a block 849 where a message is sent to the narrow band switch notifying the switch that the connection is now reserved, and the process is then marked in a state with the physical connection initiated in a block 851. In the Figure 8d, the process is initially waiting in a state with a physical connection started, block 853. The SE then, in a block 854, receives a message from the narrowband switch notifying the SE that the connection must be fully connected in one direction, that is, a complete unidirectional connection. Then, the SE identifies the type of termination port in an 855 block. If the termination port type is terminated as being a real physical port, branch 856 is taken and the SE sends commands to a full unidirectional connection of the terminating port in a voice multiplexer in a block 858 and then receiving a voice multiplexer acknowledgment message recognizing that the unidirectional complete connection in the voice multiplexer has been completed, from the voice multiplexer in block 859. process then continues to block 860. If, on the other hand, if the type of terminating port is determined as being a virtual trunk in block 855, branch 857 is taken and the process advances directly to block 860. In block 860 , the SE identifies the type of port of origin. If it is determined that the source port is a real physical port, branch 861 is taken and the SE sends commands to a full unidirectional connection of the originating port in the corresponding voice multilplexor in a block 863, and the voice multiplexer responds with a message of recognition to the SE when it - - carries out the unidirectional complete connection in the voice multiplexer, block 864. The process then proceeds to a block 865. If, on the other hand, the source port type is determined to be a virtual trunk in block 860, Branch 862 is taken and the process proceeds directly to block 865. At block 865, the SE notifies the narrow band switch, that the connection is completely unidirectionally connected and the process then proceeds to a block 866 where the process is marked in a state with the physical connection started. In Figure 8e, the process is initially waiting in a state marked with a physical connection initiated, block 871. The SE then, in block 872, receives a message from the narrowband switch notifying the SE that the connection is going to be completely connected in both directions, that is, completely bi-directionally connected. Then, the SE identifies the type of terminating port in a block 873. If the terminating port type is determined to be a real physical port, branch 874 is taken and the process continues to block 876.

In block 876, the SE commands a complete bidirectional connection of the terminating port in a multiplexer of the corresponding voice, and the voice multiplexer returns an acknowledgment to the SE when the full bidirectional connection is made, block 877. The procedure then proceeds to a block 878. If, on the other hand, it is determined that the terminating port it will be a virtual trunk in block 873, branch 875 is taken, and the process continues directly to block 878. In block 878, the SE identifies the type of source port. If the source port type is determined to be a real physical port, branch 879 is taken and the process continues to a block 881. In block 881, the SE commands a complete bidirectional connection of the origin port in the port. corresponding voice multiplexer, and the voice multiplexer returns to a recognition message to the SE when the full bidirectional connection is made, block 882. Then, the process continues to a block 883. If on the other hand, the port of origin is determined as being a virtual trunk in block 878, branch 880 is taken, and the process proceeds directly to block 883. In block 883, the SE notifies the narrow band switch that the connection is completely bi-directionally connected and the process then moves towards a block 884 where the process is marked in a state with a physical connection completely connected. In Figure 8f, the process is initially in a state waiting for a fully connected connection, block 886. The SE then receives a fully established connected connection release message from the narrowband switch in a block 887. The process then continues to block 888, where the SE identifies the type of port of origin. If the source port type is determined to be a real physical port, in block 888, branch 889 is taken, and a message requesting the release of the physical resource is sent to the corresponding voice multiplexer in a block 891, and the voice multiplexer returns a message confirming that the resource is now released in a block 892. The process then advances to a block 894. If, on the other hand, the source port is determined as being a virtual trunk in block 888 , the branch 890 is taken and the virtual trunk is marked as being idle in a block 893. The process then proceeds to block 894. In block 894, the SE identifies the type of terminating port. If the type of termination hole is determined to be a physical port real, in block 894, branch 895 is taken and a message is sent requesting the release of the physical resource to the corresponding voice multiplexer in a block 897, and the voice multiplexer returns a message confirming that the resource is now released in a block 898. The process then advances to a block 899a. If, on the other hand, the terminating port is determined as being a virtual trunk in block 894, branch 896 is taken and the virtual trunk is marked as idling in a block 899, and the process then proceeds to block 899a . In block 899a, the SE notifies the narrowband switch that the release of the connection is now taking place, and the process proceeds to a block 899b, where the process is marked as idle. In Figures 9a-9e, the logic used in a voice multiplexer (VM) to obtain ATM switching of a voice connection is illustrated as flow charts. Thus, in block 901 in Figure 9a, the process is unoccupied. Then, if a message to retain the source resources in the VM is received from SE in a block 903, the VM allocates hardware resources in the VM in a block 907, and the process advances to a block 919 where the process is processed. Place in a state with a reserved port. Yes, when the process is in the state - unoccupied in block 901, a message is received from the SE to retain the terminating resources in the VM in block 905, the VM allocates the hardware resources in the VM in a block 909 and the process advances to a block 911 where the VM identifies whether a new ATM connection is required or if an existing ATM connection can be used. If a new connection is required, branch 913 is taken, and a message is sent to the originating side informing it that a connection is required with the exit port identified with the termination AESA and a call identification for correlation. The process then proceeds to block 919. If on the other hand, an existing connection can be used, branch 915 is taken and the procedure continues to a block 921. In block 921, an ATM connection is selected for the call in question and is associated with the port of departure. Then, the VM sends a message requesting the subchannel to the source VM in a block 923 and the process then proceeds to a 925 block. In block 925 the VM informs the SE that the physical connection is now reserved, and the process then it is placed in a state with the reserved physical connection in a block 927. In Figure 9b, the process in the VM is initially in a state with the reserved port, block 941.

If the VM then receives a request for a new ATM connection from a source VM in a block 943, the process proceeds to a block 945. In block 945, the VM associates the ATM connection with an output port to a end user, eg, a PBX. Then, in a block 947, the VM sends a call processing message to the ATM switch in the ATM network to which the VM is connected informing the processing ATM switch, and sends a message to the SE informing the SE that the output port and connection to the source port are now reserved in a block 949. The process then proceeds to block 975. If the process when it is waiting in the state with the reserved port in block 941 receives a message requesting a connection from the SE in a block 951, the process advances to a block 955. In block 955, the VM determines whether a new or existing ATM connection is to be used. If the VM determines that a new ATM connection is to be used, branch 957 is taken and the process continues to a block 961. In block 961 a message is sent requesting a new ATM connection to the ATM network, and the new ATM connection connects to the incoming port and the process continues until block 975.

If, on the other hand, it is determined in block 955 that an existing ATM connection is to be used, branch 959 is taken. The process then proceeds to a block 963 where a subchannel is selected in the existing ATM connection and is connects to the incoming port, eg, to a PBX. Then, the VM sends a message requesting a reservation of the subchannel to the terminating VM in a block 965, after which the process continues to block 975 where the process is placed in a state with the reserved physical connection. If the process when waiting in the state with a reserved port in block 941 receives a message requesting a subchannel to a terminating VM in block 967, the process proceeds to block 968 where it is determined whether the VM is in a state of origin or termination. If the VM is ending, the process advances to a block 969, through a branch 968b. In block 969 the VM associates the subchannel with the output port. Then, the VM sends a message to the SE informing the SE of the output port and the connection to the source port are now reserved in a block 971, and the process then proceeds to a block 973 where the process is placed in a state with the reserved physical connection.

If it is determined in block 968 that the VM is in the state of origin, branch 968a is taken. The process then proceeds to a block 970. In the block the VM associates the subchannel with the input port. The process continues to block 973. In Figure 9c, the process is initially waiting in a state with a reserved physical connection, block 977. A unidirectional complete connection message is then received by the VM in a block 978. Then , an alert message is sent to the ATM network in a block 979 informing the ATM switch so that the alert signal is now present in the VM, and then a acknowledgment message informing the SE of the unidirectional complete connection that is sent to the ATM. has established is returned to the SE in a block 980. Then, the process is placed in a state with the reserved physical connection in a block 981. In Figure 9d, the process is waiting initially in a state with the physical connection reserved, block 991. The VM then receives a message for a bidirectional complete connection from the SE in a block 992. Then, the VM identifies whether the VM is in the terminating state or the origin in a b 993. If the VM is in the state of origin, branch 994 is taken and the process advances to a block 996. In block 996, the process waits until the connection message from the ATM switch containing the information on that connected side that has now accepted the call is received from the ATM network, if it has not already done so. The process then continues to a block 998. If the VM is determined to be in a terminating state in block 993, branch 995 is taken and the process proceeds to a block 997, where the connection message is sent to the ATM network requesting that the connection be fully connected. Then, the process continues to block 998 where the VM returns an acknowledgment message to the SE informing the SE that the full bidirectional connection has now been established. Then the process is placed in a state with an active connection. In Figure 9e, the process is initially waiting in a state with an active connection, block 982. The VM then in a block 983 receives a message from the SE to release the connection and release the resources in the VM. The process then proceeds to a block 984. In block 984, the VM releases all resources associated with the VM call, and the process continues to block 985. Next, in block 985 the VM determines whether the ATM connection existing will be released or not. If the decision in block 985 is no, branch 986 is taken and the process continues to a block 989. If the decision in block 985 is yes and branch 987 has been taken, a message is sent to the ATM network to release the ATM connection that is, all ATM switches involved in the connection, in a block 988. Then, the process proceeds to block 989 where a message informing the SE that the release request received in block 983 has now been completed is sent to the SE. The process then returns to the idle state in block 990. The method and system as described herein can also be used for other network services where existing systems and networks provide service logics but where the mechanism of fundamental transport will be changed to ATM. An example is the Frame Relay Service. In addition, using the method and the system as described, bandwidth resources are used more efficiently since all switching is carried out by ATM independently of the application. Considerable investments to provide support for intelligent services through existing systems can be reused in an efficient manner and therefore reduce the time to the market for the introduction of services added to the value.

Claims (12)

CLAIMS:

1. A telecommunication network comprising an ATM network, characterized by - a means connected to the ATM network for identifying a telephone call entering an ATM network on a first port, a means for identifying the port on the network of ATM through which the call will be output and, - a means to return the address of the output port to the input port to send the address of the input port to the output port whereby the call can be switched directly through the ATM network.

2. A network in accordance with the claim 1, characterized by a means connected with the means for identifying the output port and with an STM switch for emulating an STM connection with the STM switch.

3. A network according to any of claims 1-2, characterized by means for establishing a new switched connection through the ATM network for each new telephone call using the sending of ATM signals.

4. A method for establishing a voice connection in an ATM network, characterized by the steps of identifying the input port in which the connection enters the ATM network, - identifying the address of the outgoing port in which the connection is going to exit from the ATM network, return the address of the exit port to the entry port, or send the address of the entry port to the exit port, whereby the entry port can direct the voice traffic directly to the port of entry. output only using ATM switching in the ATM network.

5. A method according to claim 4, characterized in that the connections through the ATM network are stable using an ATM signal sending.

6. A method according to any of claims 4-5, characterized in that the information for identification of the call is sent together with the address in order to correlate the address with the call.

7. A unit to emulate an STM connection to a narrow band switch connected to a network telecommunication comprising an ATM network, characterized by a means for storing trajectory requests received from the narrowband switch, - a means for requests for recognition paths to the narrowband switch, and a means for associating the entry into an exit port.

8. A unit according to claim 7, characterized by means for contacting the broadband terminals connected to the telecommunication network.

9. A unit according to claim 8, characterized by means for sending the address of a broadband terminal to another broadband terminal connected to the same network.

10. A unit according to claim 9 ,. characterized because the address sent is the End ATM System Address (AESA).

11. A unit according to any of claims 9 or 10, characterized by - - - a means for sending the call identification information for correlation with the address.

12. A unit according to any of claims 7 to 11, characterized by - a means for deciding whether the already existing connection through the ATM network is to be used or whether a new ATM connection is to be established.