CN1324546A

CN1324546A - Signalling in a telecommunications system

Info

Publication number: CN1324546A
Application number: CN 99812457
Authority: CN
Inventors: L·格拉夫
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 1998-08-24
Filing date: 1999-08-23
Publication date: 2001-11-28
Also published as: EP1108333A1; AU5623999A; WO2000011882A1; JP2002523991A; CA2341169A1

Abstract

A method of passing a Clear Back (CLB) and/or REANSWER message from a PSTN access point (2) to a call charging point via an H.323 network (7) which uses a DSS1 based signalling protocol. The method comprising defining call clearback and reanswer parameters and including one or other of the parameters as a Notification Indicator information element of a notify message of the DSS1 based protocol, for transmission over said network (7), in response to generation of a Clear Back (CLB) or REANSWER message at the PSTN access point.

Description

Signaling in the telecommunication system

The present invention relates to the signaling in telecommunication system, more particularly, though and inessential, relate to the transmission of the signaling data in network H.323.

Traditional telecommunications network is referred to as public switch telephone network (PSTNs), and it uses a large amount of transmission and signaling protocols to communicate between user and network node.For example, transmit with the NUP agreement at the interoffice signaling of the United Kingdom, some other country then is to use Telephone User Part.

Recently, released a kind of novel telecommunications network that is referred to as Integrated Service Digital Network.ISDN can realize between the network node and between user and its local exchange.In the link between user and this user's local exchange (user " access point "), ISDN uses the signaling protocol that is referred to as digital subscriber signaling system NO.1 (DSS1), another agreement that is referred to as ISDNYong Hubufen (ISUP) then is used for transmitting the signaling data between the network, that is signaling between node.Under normal conditions, a calling connection will be by more than one PSTN part and more than one ISDN part.

In the telecommunication market of current competition, can provide basic, auxiliary and added value extensive and variable professional and to make terminal use's functional expenses minimum be vital to the telecommunications operator.Therefore, current telecommunications network, particularly ISUP have developed to such an extent that can transmit many message and parameter about this business between the node (or signalling point) of diverse network.

Conventional telecommunications network designs to such an extent that make calling party (party A-subscriber, A side, A number usually, A address etc.) responsible, therefore undertake the expense of calling and/or connect hours, and callee (party B-subscriber, B side, B address etc.) do not bear the expense of the connect hours of any receipt of call and/or receipt of call.Paying can or (for example be opened telephone bill) (so-called prepayment method of calling) in advance afterwards.

Call is usually by its duration charge.Also available other Freight Basis of network operation merchant, the distance between the user etc. for example so that can reliably charge, monitors the calling just carried out and pay imformation is for example delivered to the call charge point (CCP) of the calling party of carrying out at party A-subscriber's local exchange.By the way, also available so-called pulse metering and toll telephone bill (TT) charge.When end of calling, promptly when calling out release, notification call charging point and termination telephone are chargeed.

The conventional telecommunications network that is used for transmitting sound and other user profile relies on private telecommunication network structure and host-host protocol (that is, PSTN and ISDN) usually.Yet, along with in the recent sharp increase aspect the digital data transfer, used the driving of Internet and World Wide Web especially, promoted in telecommunications industry, to use more general structure and host-host protocol.This promotion mainly is to be subjected to interconnect between telecommunications network and other data networks the driving of operability, secondly is the driving that is subjected to the advantage that conventional data net system has than conventional telecommunication system on cost.

In 1996, International Telecommunication Association (ITU) formulated the standard that " interference networks " formed at local area network (LAN) (LANs) with by the local area network (LAN) of a plurality of interconnection go up transmitting multimedia data.H.323 this standard is referred to as, and its version in 1998 is referred to as H.323 version 2.H.323 fundamental sum core has provided the transmission to the voice data of digitlization and compression.Yet, H.323 also can be used for transmission of video and other data modes.Such as MicrosoftNetmeeting ^TMMedia product in implemented H.323.Currently exist introducing H.323 as a kind of demand of means of between the signalling point of telecommunications network, communicating by letter.This can cause H.323 must with the situation of ISDN and PSTN coexistence.Typical situation may comprise calling party and callee's (for example using NUP or TUP) of the PSTN Access Network that is connected to separately, and signaling link is by ISDN net (using ISUP) with partly provided by net H.323 in the middle of the part.

H.323 force force to use based on be used for consulting two H.323 between the node ITU standard of the DSS1 of call setup (being referred to as Q.931 sometimes) signaling H.225, to set up the channel that a terminal can send user and signaling data.In addition, DSS1 is essential to some maintenance and termination function.

Inventor of the present invention has been found that, the signaling protocol based on DSS1 of existing employing signaling protocol H.323 can not be admitted some signaling information, and these signaling informations can produce in telecommunication system and existing PSTN and ISUP standard configuration these signaling informations.The inventor recognizes again that this incompatibility has hindered in telecommunications network and introduces H.323.

In current PSTN net (being connected only in PSTN between calling party and callee), calling party (party A-subscriber) comes end call by on-hook.This causes a clear forward signal (CFS) to send to suitable call charge point (CCP) from city's PSTN switch of party A-subscriber.This calling is stopped immediately and stops to charge.Yet come the mechanism of end call then a bit different according to callee (party B-subscriber) on-hook.User's on-hook is detected in its city's switch.Send a reset signal (CLB) by city's switch to CCP, the signal that detects party B-subscriber's on-hook is sent back to CCP from the party B-subscriber.

CCP receives the termination that the CLB signal does not cause calling immediately.But the timer of CCP is picked up counting.Just in case the party B-subscriber is off-hook (the timer operation is about 90 seconds usually) before timer stops, then city's switch of party B-subscriber sends a reanswer signals to CCP.Cancel timer thus at CCP.If CCP does not receive reanswer signals before timer stops, then CCP makes and connects dismounting and stop charging.This set for example make the party B-subscriber can be on an extension set on-hook and on another extension set, can not stop this calling thereupon off-hook.

Intervening portion place in that the signaling that is provided at by the ISUP signaling between A and the party B-subscriber connects carries out CLB and reanswer signals by suitable isup message.Specifically, carry out CLB signal (suspending the indication that request is the network that is activated) by ISUPSUSPEND (time-out) message and REANSWER (second set response) signal is by ISUP RESUME message (suspend with one again to ask be the indication of the network that is activated) execution with one.

Yet the present inventor notices, starts and aforesaid second set response though ISUP caters to party B-subscriber's timer, and H.323 (H.225) is not such.This means that make in the telecommunications network of information relying on H.323 to connect to upload to deliver letters at least a portion, the party B-subscriber can not suspend a calling by way of expectations.

The objective of the invention is in order to overcome or reduce at least the above-mentioned shortcoming of existing H.323 (H.225) signaling system.

Second purpose of the present invention is for a kind of improved solution being provided, being used for an access protocol or a call charging step that sends the telecommunications network of signal based on the agreement that inserts.

The 3rd purpose of the present invention is that network configuration is planned and be need not to design current protocol signaling again for convenience, has the protocol signaling of the network that relates to IP based network and other routers especially.

The 4th purpose of the present invention is the call charging point for fear of the network that requires to reallocate.

According to a first aspect of the invention, a kind of method that transmits signaling information by data network between the communication network of a pair of employing ISUP or pstn signaling is provided, this method comprises with agreement H.323 and communicating by the data network by the signaling data of carrying out based on the DSS1 agreement of expansion, so that the transmission of the ISUP/PSTN information that can not be transmitted by DSS1 to be provided.

Speech recited above " expansion " is to be used for definition: change agreement based on DSS1 to admit new message and/or message field.The ISUP/PSTN information that is not suitable at DSS1 does not just transmit via data network by they being encapsulated in " carrier " message as yet.

In one embodiment of the invention, this method call charging of being used to therein an ISUP/PSTN net is put an initial timer step.This method also comprises the steps: to detect a callee's hook state, and that utilizes an expansion sends a timer initiation requests signal from callee's access point to call charging point based on the DSS1 agreement.Callee's and then off hook state may cause to call charging point and send a REANSWER (second set response) indication, termination timing device thereupon.

Best, detect hook state at callee's access point, what the timer indication request was then utilized expansion sends to the call charging point based on the agreement of DSS1 from callee's access point, and calling party's call charging point is connected to or is linked to calling party's access point.

Best, the timer index signal is one starts the call packing timer, and pause timer one stops being about to this call tear down.

Can expand to the charging point that REANSWER signal (RES) is sent to the calling party based on the agreement of DSS1 and cancel the call packing timer.

Best, described use data network H.323 is a Packet Switch Data Network.And best, this network is an IP network.This network is a LAN (local area network (LAN)), an internet, or plural these combination.In these cases, on IP stack, dispose H.323 protocol stack.

According to a second aspect of the invention, a kind of method is provided, be used for based on the network of the signaling protocol of DSS1 a Clear Back (CLB) and/or REANSWER message being sent to a call charging point from the PSTN access point by a use, this method comprises: definition call out reset and second set response parameter and parameter in this or that as a notice indication information code element (element) based on the notification message of DSS1 agreement, be used for transmitting by described network according to the Clear Back (resetting) or the REANSWER information that produce at the PSTN access point.

Best, the off-hook operation according to the callee can provide notice indication information code element (element), is used for transmitting to charging center or calling party's access point from callee's access point, and wherein this code element (element) is transmitted an off-hook notification value.Best, according to callee's on-hook operation, transmit a hang-off notification value by notice indication information code element.

Best, this method comprises from callee's access point inquiry callee, to detect the on-hook operation.

Best, by net H.323 use described signaling protocol based on DSS1 set up be controlled at described network on be connected.

According to a third aspect of the present invention, a kind of device that is used for transmitting between the telecommunications network of a pair of employing ISUP or pstn signaling by a data network signaling data is provided, this device comprises that wherein signaling data can not be by the transmission of the ISUP/PSUP message of DSS1 carrying to provide based on the carrying of DSS1 agreement by what expand with H.323 agreement is by the data network communicating devices.

According to a fourth aspect of the present invention, an a kind of data network transmits signaling data between a pair of telecommunications network that adopts ISUP or pstn signaling method of passing through is provided, H.323 this method comprises uses that agreement communicates by data network, wherein signaling data by in the H.323 agreement of DSS1, constitute based on Q.76x agreement carrying.

In order to understand the present invention better and to show effect of the present invention, the existing accompanying drawing of consulting as an example of the present invention.

Fig. 1 schematically shows a telecommunications network that transmits user and signaling data by IP network between the switch of this net;

Fig. 2 shows the signaling information stream in the network of Fig. 1;

Fig. 3 shows the on-hook of explanation in the network of Fig. 1 and the transmission flow graph of off-hook signaling information.

Below description based on ITU standard H.323, this standard forces to use a standard based on DSS1 to set up and maintain two callings between the node that H.323 activates to connect.In example shown in Figure 1, two PSTN switches of a telecommunications network 1,2 use TUP signaling protocol and ISUP gateway switch 3,4 separately to communicate.The ISUP switch uses ISUP interface and H.323

gateway node

5,6 separately to communicate by letter conversely.

Gateway node

5,6 is by a packet-switched data network 7 (being IP network in this case).More particularly, H.323 protocol layer be positioned at tcp/ip layer in the protocol stack of two

gateway nodes

5,6 above.

Switch 1,2 is that separately user terminal 8,9 provides PSTN access point to telecommunications network.In calling is under the situation between two terminals 8,9, and the terminal 8 of set up calling out is referred to as the party A-subscriber and another terminal 9 is referred to as the party B-subscriber.Should be realized that switch 1,2 can be positioned at single operator's network, maybe can be positioned at different operators' network.Should be realized that also terminal 8,9 can be connected to separately access switch 1,2 by middle routing node.

For can be between switch 1,2 the seamless delivery signaling, H.323

gateway node

5,6 utilizes the DSS1 agreement of the extended version of H.323 appointment.More particularly, the DSS1 agreement is extended to and can makes some PSTN (with relevant ISUP) parameter by 7 transmission of TCP/IP net.

The collection person for relevant call charging information is served as in the calling that switch 1 starts for party A-subscriber 8.More particularly, switch 1 will start and termination signal such as calling out, and calling party and callee position be sent to call charging point (or toll telephone charging device) 10, so that information and some intended service information (the special business information that comprises the user) of receiving according to switch 1 are calculated the long distance telephone fee of given calling.

Basic DSS1 standard definition is utilized a notification message with following structure, wherein reference (sub-project) is illustrated in the corresponding information code element reference in the DSS1 standard, direction indication is by direction (the n=network of the code element of notification message transmission, and length is represented 8 byte Baud Lengths u=H.323 user):

Information code element	With reference to (sub-project)	Direction	Type	Length
Information code element	With reference to (sub-project)	Direction	Type	Length
Protocol discriminator	4.2	Both direction	M	?1
Protocol discriminator	4.2	Both direction	M	?1	Call reference	4.3	Both direction	M	?2
Type of message	4.4	Both direction	M	?1	Call reference	4.3	Both direction	M	?2
Type of message	4.4	Both direction	M	?1	Bearing capacity	4.5	?n→u	?0	?2-12
Notification indicator	4.5	Both direction	M	?3	Bearing capacity	4.5	?n→u	?0	?2-12
Notification indicator	4.5	Both direction	M	?3	Show	4.5	?n→u	?0	≥2

In 6 message code elements, the notification indicator code element has been defined as two significant values or state in existing DSS1 standard.They are:

Bit

????7?6?5?4?3?2?1

?0?0?0?0?0?0?0 ?0?0?0?0?0?0?0

The user suspends the user and recovers

The every other value of current reservation.

Here advised to be to the expansion of DSS1 agreement detect off-hook and on-hook operation so that provide a notification indicator code element to make can be transmitted in the party B-subscriber.These two operations are assigned to two in the retention of notification indicator code element.

For example, consider a calling between terminal 8,9, carry out with party B-subscriber 9 by on-hook stop this calling (call tear down that the party B-subscriber starts, B-ICC).In order to start the call packing timer, CLB signal of call charging point 10 essential receptions.Switch 2 inquiry callee terminals 9 detect the on-hook operation, and one detects and promptly produces a CLB signal.Switch sends the CLB signal to ISUP gateway switch 4, and switch 4 produces a corresponding SUSPEND (time-out) signal, and this signal is sent to H.323 gateway node 6.Gateway node 6 produces a NOTIFY (notice) signal, and wherein the notification indicator code element has a signal corresponding to CLB.Gateway node 6 then is sent to the H.323 node 5 of side gateway that starts with this notification message by IP network 7.This gateway node 5 produces an ISUP suspending message and sends it to ISUP gateway switch 3, and switch 3 produces a CLB signal, and the CLB signal then is sent to CCP10, and CCP10 starts pause timer thereupon.

Just in case (for example 90 seconds) its phone of party B-subscriber's " second set response " in the scheduled time after previous on-hook, this also can be detected by switch 2 and produce a calling second set response message and be sent to ISUP gateway switch 4.Gateway switch 4 produces ISUPRESUME (recovery) signal and sends it to H.323 gateway node 6.In addition, also produce notification message at gateway node 6, this message comprise as the notification indicator code element in the value of a second set response message.This message is sent to the H.323 gateway node 5 of side that starts, and is converted into an ISUP RESUME message and is sent to ISUP gateway switch 3.Form a TUP RESUME message and be sent to PSTN switch 1.RESUME message is sent to CCP10, and CCP10 stops not being terminated after this pause timer makes this calling thereupon.Fig. 2 shows and suspends and the second set response signaling flow.

Fig. 3 be an explanation between two terminals 8,9 call setup and then stop the related step of this calling by party B-subscriber 9.

Those skilled in the art that will recognize, can do various modifications to the embodiment of foregoing description and need not to leave scope of the present invention.For example, another kind as an existing DSS1 agreement of expansion is selected, can be by replacing agreement Q.763 to obtain with the DSS1 agreement and the working in coordination of the front H.323 at ISUP, Q.763 agreement is the agreement that ISUP uses, and can guarantee complete cooperatively interacting like this.

Claims

1. one kind is passed through a network transmits signaling information between a pair of telecommunications network that adopts ISUP or pstn signaling method, this method comprises: using H.323, agreement communicates by described network, wherein signaling data is by the transmitting based on the DSS1 agreement an of expansion, and this Extended Protocol can provide the ISUP/PSTN that can not transmit DSS1 transmission of Information.

2. a basis the process of claim 1 wherein that this method is used to be enabled in the timer step of the call charging point of one of them net in the ISUP/ net, and this method also comprises the steps:

Detect callee's hook state; With

Utilize expansion to start request from callee's access point to call charging point transmission timer based on the expansion of DSS1 agreement.

3. method according to claim 2, the callee's who wherein follows off hook state can cause to call charging point and send REANSWER (second set response) request, connect thereby rebuild.

4. method according to claim 2 or 3, wherein hook state is detected at callee's access point, and timer to start request be to utilize expansion to send to call charging point based on the agreement of DSS1 from callee's access point, calling party's call charging point is connected to the access point that is linked to the calling party.

5. method according to claim arbitrary among the claim 2-4, wherein the timer enabling signal is (CLB) signal that resets, this signal makes and starts the call packing timer immediately, becomes to remove this calling when this timer stops.

6. method according to the arbitrary claim in front wherein is expanded based on the agreement of DSS1 and comprises and be used for a REANSWER or REANSWER signal (RES) are sent to calling party's charging point with cancellation call packing timer.

7. method according to the arbitrary claim in front, wherein said use data network H.323 is a Packet Switch Data Network.

8. method according to claim 7, wherein said data network is an IP network.

9. one kind is adopted a net based on the DSS1 agreement will reset (CLB) by one and/or second set response message is sent to the method for a call charging point from a PSTN access point, this method comprises: definition is called out and to be resetted and second set response parameter and comprise one or more parameters as the notification indicator information code element based on the notification message of DSS1 agreement, be used for according to the PSTN access point reset or being created in of second set response message describedly transmitted on the net.

10. method according to claim 9, wherein the notification indicator information code element is used to be transferred to charging center or calling party's access point according to the off-hook operation the callee from callee's access point, and wherein said code element transmits the off-hook notification value.

11. the method according to claim 9 or 10, wherein this method comprises: detect an off-hook operation from callee's access point inquiry callee.

12. the method according to arbitrary claim among the claim 9-11, H.323 wherein said signaling protocol based on DSS1 is used for setting up and is controlled described online being connected.

13. one kind is used for by a data network, between the telecommunications network of a pair of employing ISUP or pstn signaling, transmit the equipment of signaling data, this equipment comprises: be used for using H.323 agreement, by signaling data be the device that communicates on the data network that transmits based on the DSS1 agreement by expansion, described expansion can provide transmission based on the DSS1 agreement to the ISUP/PSTN message that can not be transmitted by DSS1.

14. one kind by a data network, between the telecommunications network of a pair of employing ISUP or pstn signaling, transmit the method for signaling data, H.323 this method comprises uses that agreement communicates on this data network, wherein signaling data transmits by substituting the DSS1 agreement based on (ISUP) agreement Q.76 in agreement H.323.