KR100733189B1 - Methods and system for fast session establishment between equipment using h.324 and related telecommunications protocols - Google Patents

Abstract

The present invention relates to a method of establishing a multimedia communication (multimedia "call") between equipment (terminals). More specifically, the present invention meets other standards and recommendations related to or derived from ITU-T H.324 Recommendations and 3G-324M Recommendations developed and adopted by Third Generation Joint Projects (3GPP and 3GPP2). It provides a method for reducing the time required for establishing a call between terminals. More specifically, the present invention relates to (i) connecting H.245 messages that match the type and format of the medium and data to be exchanged and required to pass between terminals at the beginning of a call to establish the capabilities of the two terminals. Methods and apparatus, (ii) methods and apparatus to use non-standard H.245 messages or non-standard H.245 messages with non-standard fields to accelerate such setup, and (iii) inform each terminal of the capabilities of another terminal, A method and apparatus for proposing the type and format of media and data exchanged by any user-defined field available in a call signaling protocol used for bearer setup prior to initiation of step H.324 of a call.

Call, call setup time, terminal, mobile network, H.324, H.323, H.245, bearer, session setup

Description

METHODS AND SYSTEM FOR FAST SESSION ESTABLISHMENT BETWEEN EQUIPMENT USING H.324 AND RELATED TELECOMMUNICATIONS PROTOCOLS}

Cross Reference of Related Applications

This patent application is based on a claim of priority in US Provisional Patent Application No. 60/433252, filed Dec. 12, 2002, which is incorporated herein by reference.

Copyright Notice

Portions of this application include computer code owned by Macchina Pty, Inc. All rights reserved to Macchina Pty, Inc., which was copyrighted in 2003.

The present invention generally relates to a method of establishing multimedia communication (multimedia "call") between equipment (terminals). In particular, the present invention relates to terminals that implement other standards and recommendations derived from or related to such as 3G-324M developed and adopted by ITU-T H.324 Recommendations and Third Generation Joint Projects (3GPP and 3GPP2). It provides a method of reducing the time required to set up a call. By way of example only, the present invention provides a multimedia gateway that mediates multimedia communication between 3G-324M (H.324M based protocol) multimedia handsets on a mobile communication network and the protocol used at each endpoint. Although it applies to the establishment of multimedia communication between a 3G-324M multimedia handset and an H.323 based terminal in a packet network to be used, it should be appreciated that the present invention may include other application scopes.

H.324 is an International Telecommunication Union (ITU) protocol standard for multimedia communications in general switched networks (GSTN). H.324M is an extension of H.324 for operations in mobile networks, and 3G-324M is a third-generation joint program (3GPP) that defines 3GPP internal use and also defines the adaptation of H.324M adopted by 3GPP2. Is recommended. Devices and systems employing protocols based on or derived from H.324 are referred to as H.324-like equipment. H.324-type equipment may be connected to other H.324-type equipment via an exchange, and may be connected to non-H.324-type equipment through a multimedia gateway. H.323 equipment is an example of a non-H.324 type equipment. H.323 is the International Telecommunication Union protocol Standard for multimedia communication in non-guaranteed bandwidth packet networks.

An H.323-type device employs a protocol based on or derived from the H.323 protocol.

In keeping with its universality, the term "H.324" will refer to H.324 type equipment, including H.324M and 3G-324M, and the term "H.323" will refer to type H.323 equipment. .

In addition, while maintaining universality, the term “equipment” is used as referring to either user-side equipment such as a handset or network-side equipment such as a switch or gateway. In addition, "equipment" and "terminal" are used interchangeably, and both refer to the same meaning in this document.

If a call is made between devices that are one embodiment of H.324, H.324M, or 3G-324M, the first step of the call is to establish an end-to-end bearer between the devices. To set. This step is called call signaling and is outside the scope of H.324 except where modems and General Switched Telephony Networks are used. The second step of the call is to establish a H.324 session and provide a means for transmitting video, sound, and data between devices in a format understood by and supported by the device. For this purpose, H.324M uses two more ITU-T Recommendations.

The first of the recommendations used is H.223 "Multiplexing protocol for low bit rate multimedia communication". H.223 specifies a frame-oriented multiplexing protocol that allows any combination of digital voice, video, and data (eg, command and control) to be transmitted over a single communication link. H.223 has a number of modes of operation specified in Annex A, B, and C of the H.223 Recommendations for increasing resilience in the event of an error. These are also known as Mobile Levels 1, 2, and 3. H.223, to which none of these appendixes apply, is also considered to operate at movement level 0 (baseline). H.324 has the concept of Logical Channels, a way of providing virtual channels over circuit-switched links. The role of the multiplexer is to combine the (multiple) portions of the data chunks written to the logical channel into frames known as a Multiplexer Protocol Data Unit (MUX-PDU). Logical channel 0 is always available and is used for Command and Control. Data (voice, video, command, and control, and other general data) is passed to / from the H.223 multiplexer through chunks of bits called service data units (SDUs). Before being multiplexed, different SDUs pass through Adaptation Layers where additional information can be added for purposes such as error detection, sequence numbering, and retransmission request.

The second of these recommendations specifies the syntax and semantics of terminal information messages as well as the procedure of using terminal information messages for in-band negotiation at the beginning or during communication. H.245 "Control protocol for multimedia communication". These messages include transmit and receive capabilities and preferences, logical channel signals and controls, and indications. Messages specified in H.245 are indicated in the ITU-A Abstract Syntax Notation (ASN.1) and may be classified as Request, Response, Command, or Indication type. Can be. H.245 messages are encoded according to the ASN.1 standard before being sent. When the terminal sends an H.245 message of the request type, the message requests that the remote terminal send an appropriate message of the response type. If a response (sometimes referred to as Acknowledgement, or Ack) is not received within a certain time, the sending terminal will resend the request, and if no response is received for the repeated request, other appropriate action is taken. Will take. Retransmission of requests can occur many times. Many H.245 messages associated with call setup are of request type.

H.245 also requires a reliable link for proper operation. The basic means specified in Annex A of H.324, which provides this, collectively include one or more H.245 messages known as MultimediaSystemControl PDUs, and in this document known as H.245 PDUs. Previously, the Simple Retransmission Protocol (SRP) or Numbered Simple Retransmission Protocol (NSRP), which is formed of SRP Command Frames, is used, and the receiving terminal is an SRP Command Frame. Send an SRP Response Frame (sometimes referred to as an SRP Acknowledgment). No further H.245 is sent by the terminal until the SRP acknowledgment for the last message is received.

The combined effect of the transmission request of the H.245 response message for each received H.245 request message and the receipt request of the SRP acknowledgment for each transmitted SRP command frame is a single H. .245 This means that it may take some time for the request message to be successfully sent. The communication involved in sending an H.245 request message from one terminal (A) to another terminal (B) and returning an H.245 acknowledgment (Ack) message is shown in FIG. 1A, and FIG. It shows the SRP Command Frames (SRP CF) and SRP Response Frames (SRP RF or SRP Ack) that are associated when H.245 messages are formed into a single SRP command frame. The H.324 standard allows multiple H.245 messages to be linked in one SRP command frame. However, this capability is often not implemented, such as when terminals can only respond to the first H.245 message they encounter in an SRP command frame. In some cases, terminals that do not support this capability may malfunction when they receive an SDU containing multiple H.245 requests or responses.

Here, the series of H.245 requests and responses shown in FIG. 1A are referred to as "round trips" and the time taken to complete them is called "round trip delays".

The key steps involved in setting up and connecting a typical H.324 call are:

1. Call signal (bearer setting)-outside the scope of H.324. Normally, signal is sent through ISDN if the modem connection is GSTN or through the mobile switching center if moving.

2. Mobile level detection (MLD)-when the mobile levels match between devices. This step is performed by H.324 equipment that supports mobile extensions such as H.324M and 3G-324M equipment.

3. Terminal Capability Exchange (TCS)-Send H.245 messages.

4. Master Slave Determination (MSD)-Send H.245 message.

5. Open / Closed Logical Channels (OLC)-Send H.245 message.

6. Multiplexer Table Entries Exchange (MTE)-Send H.245 messages

Steps 3 to 6 are executed using a series of H.245 request and response messages, as described above and shown in FIG. 1A. The entire series of request and response messages associated with one H.324 call is shown in FIG. 1B. Note that the order of steps 5 and 6 may be interchanged. It should be noted that steps 3 to 6 relate to the procedure defined by the underlying state machines, also known as Signaling Entities. Related signaling entities are as follows.

1. Capability Exchange Signaling Entity (CESE)

2. Master Slave Determination Signaling Entity (MSDSE)

3. Logical Channel Signaling Entity (LCSE)

4. Multiple Table Signaling Entity (MTSE)

Once these steps are completed, the medium (image, sound, and data) can move between terminals. Note that the H.245 messages flow over logical channel 0 carried by a multiplexer predefined as previously described and pre-defined with multiple table entry zero. Once other multiplexed table entities are exchanged, they can also be used with H.245 messages.

The above important steps are often processed sequentially. However, this causes ten H.245 message round trip delays to establish an H.324 session with two logical channels in each direction. In addition, the SRP scheme used in H.324 / H.245, which requires that an SRP message be received by an endpoint for every message sent, regardless of whether it is associated with the same signaling entity or not. Or numbered version (NSRP) if the move level is greater than zero, further restricts the area of pipelined messages on the network and slows down call setup than otherwise. SRP messages are not shown in FIG. 1B.

For H.324M, the terminal capability set request (TCS) step described above and shown in FIG. 1B precedes the movement level detection / multiplexer synchronization step. It consists of each terminal sending a repeating pattern of bits (flags) that indicate the best level of movement. Each terminal checks the flag it is receiving. If the flags indicate a lower movement level, the terminal drops to this same level. This step is completed when both terminals are sending the same flag string.

When a call is made from a terminal, which is an embodiment of H.324, it originates from the set of procedures described above, which are required to occur to establish an H.324 call, and the time at which call signaling is initiated and Long call, the time between the start of the exchange of voice and video between an H.324, N.324M, or 3G-324M and a terminal other than H.324 or H.324. Easy to experience setup time

ITU Recommendation H.323 uses H.245 in a similar way that H.324 signals command, control, and indication messages related to a call. Unlike H.324, H.323 has a number of features that improve call setup time between H.323 equipment. Similar techniques exist for the IETF Session Initiation Protocol (SIP).

In this way, a technique is needed to speed up call setup between H.324 type terminals and other terminals, ie between H.324 type and directly between terminals such as H.323 and multimedia gateways. Differences between the H.324 protocol (and extensions such as H.324M and 3G-324M) and H.323 and other protocols indicate that additional aspects should be considered when introducing call setup speed enhancement techniques for H.324-type terminals. it means. Such differences include information about the transport level and message transmissions in which they are used and information related to H.323 multiplexers such as multiplex table entries, adaptation layers, and so on.

The present invention relates generally to communication technology. More specifically, the present invention meets other standards and recommendations related to or derived from such ITU-T H.324 Recommendations and 3G-324M Recommendations developed and adopted by the Third Generation Joint Projects (3GPP and 3GPP2). It provides a method for reducing the time required for establishing a call between terminals. More specifically, the present invention provides a method of (i) connecting H.245 messages that match the type and format of the medium and data to be exchanged and required to pass between terminals at the beginning of a call to establish the capabilities of the two terminals. And apparatus, (ii) methods and apparatus for using non-standard H.245 messages or non-standard H.245 messages with non-standard fields to accelerate such setup, and (iii) inform each terminal of the capabilities of the other terminal, A method and apparatus for proposing the type and format of media and data exchanged by any user-defined field available in a call signaling protocol used for bearer setup prior to the start of step H.324.

These methods can be used individually or several times to shorten the time it takes from when the user requests the establishment of a call to when the media exchange between terminals begins. By way of example only, the present invention relates to a 3G-324M multimedia hand in a packet network using a multimedia gateway that arbitrates protocols used between 3G-324M (H.324M based protocol) multimedia handsets in a mobile communication network and at each endpoint. Although applied to the setting of multimedia communication between a set and an H.323 based terminal, it should be noted that the present invention can be applied to a wider range.

In accordance with the present invention, techniques for reducing the number of sequential steps required to set up an H.324 type call are provided through a number of methods that can be used individually or in parts.

At least three types of methods are described to reduce the number of these steps. These methods are called Type I, Type II, and Type III, and are numbered for ease of reference. These methods may be combined or, depending on the embodiment, may be used with conventional techniques. Those skilled in the art to which the present invention pertains (hereinafter referred to as "the skilled person") can recognize many variations, alternatives, and modifications.

In a specific embodiment, the methods are as follows.

1. Type I: Link H.245 messages to reduce the number of standard SRP / NSRP command messages to initiate media communication.

2. Type II: Incorporating H.245 non-standard message transfer capabilities to aggregate information about equipment associated with a call so that the number of H.245 and SRP / NSRP message exchanges is minimized to initiate media communication.

3. Type III: Incorporation of equipment preference information within the call signaling protocol exchange so that there is no need to exchange additional information between the equipment to initiate media communication following call signaling.

In each case the method provides a means to restore the operation of a terminal in accordance with the H.324 standard.

Type I: Speed Improvement by Linking H.245 Messages in SRP / NSRP Command Frames

This method is a means to reduce the number of H.245, SRP / NSRP messages and associated round-trip delays, and provides the ability to link multiple H.245 messages within a single SRP / NSRP (H.245 PDU) command frame. Promote. H.245 messages must be chained in a way that does not break the dependency.

The use of H.245 in H.324 allows the equipment to connect multiple H.245 elements into one PDU. This allows two round trips for each request / response pair because of the need for each SRP / NSRP response to be received for each H.245 PDU before subsequent PDU transmissions are allowed. There is no need.

The method uses H.245 connected to transmit multiple H.245 messages, each H.245 message originating from different signaling entities having no dependency on each other in one H.245 PDU. .

Interoperability with equipment that does not support the associated H.245 means that such equipment ignores the second and subsequent H.245 elements in the PDU and if the ignored message is an H.245 request message, This can be accomplished by noting that no H.245 reply message will be sent. Therefore, the first connection H.245 PDU sent must contain at least two request messages, where the first message must be a Request. If only an acknowledgment for the first message is received, the transmitting equipment will resend those requests and other messages that are not answered. During this and during the transmission of any H.245 message and all accompanying H.245 messages, it should return to sending only a single H.245 message of each subsequent H.245 PDU. If a response is received for all H.245 messages in the first H.245 PDU, the transmitting equipment can continue to use the connected messages. The use of this technique will reduce the number of round trip delays if concatenated messages are supported. This method does not limit any protocol elements in addition to those already allowed and defined by the H.245 and H.324 standards. It may be considered to use existing protocols in a smart manner rather than an extension thereof.

Preferably, the present invention provides a method for initiating a call between users with reduced call set-up times using one or more communication networks. This method is provided between at least one pair of H.324 type terminals connected to one or more telecommunication networks. The method includes transmitting a call signaling message from a first terminal to a second terminal through a communication network to initiate a call, and bearer between the first terminal and the second terminal if the call signaling message is received by a second terminal. Establishing a channel, and determining a common movement level. In addition, the method determines two or more H.245 messages associated with setup parameters for an initial predetermined mode of operation, depending on the predetermined size of the SRP command frame, two or more H.245 messages. Linking them to a single SRP command frame, and transmitting an SRP command frame comprising two or more H.245 messages from a first terminal to a second terminal via a communication network. The method also includes transmitting an SRP acknowledgment message by the second terminal after the SRP command frame has been received by the second terminal, processing at least two or more H.245 messages for a predetermined period of time, And establishing an initial predetermined mode of operation between the first terminal and the second terminal over the bearer channel.

According to yet another embodiment, the present invention provides a computer readable medium comprising instructions for initiating a call between users with reduced call setup time using one or more communication networks. The computer readable medium is provided between at least one pair of H.324 type terminals connected to one or more telecommunication networks. The computer readable medium may include one or more instructions for transmitting a call signaling message from a first terminal to a second terminal through a communication network to initiate a call, and if the call signaling message is received by a second terminal. One or more instructions for establishing a bearer channel between the first terminal and the second terminal, and one or more instructions for determining a common movement level. Further, the computer readable medium may be configured according to a predetermined size of an SRP instruction frame, one or more instructions for determining two or more H.245 messages associated with setup parameters for an initial predetermined mode of operation. A second SRP command frame comprising one or more instructions for connecting two or more H.245 messages into one SRP command frame, and two or more H.245 messages from a first terminal through a communication network; Contains one or more commands for sending to the terminal. The computer readable medium may also include one or more instructions for transmitting an SRP acknowledgment message by the second terminal after the SRP command frame has been received by the second terminal, at least two or more H for a predetermined period of time. .245 one or more instructions for processing messages, and one or more instructions for setting an initial predetermined mode of operation between the first terminal and the second terminal via a bearer channel.

Type II: Speeding up using H.245 nonstandard messages

The second method of the present invention for reducing the number of sequential steps required to set up an H.324 type call proposes the use of the non-standard message transfer capability of the H.245 protocol. H.245 allows a number of ways to add nonstandard extensions. There are several ways to add non-standard messages in H.245 to speed up the call. The most interesting of these is the use of nonstandard capabilities in H.245 Terminal CapabilitySet messages and NonStandardMessage H.245 Response messages. These messages signal that call equipment can be operated in a particular way and can be used to accelerate Master Slave Determination, Logical Channel (s) to be opened, and call setup. It can be used to provide requirements and options to a remote terminal associated with a multiplexer table entry included in non-standard extensions. If the remote terminal supports this method, the remote terminal will send a signal to the calling terminal using a non-standard extension that also indicates that it accepts, suggests a change, or, for example, the multiplexer table entry it is using. Other information may be provided, including entries.

If the called terminal does not support this method, it will ignore the nonstandard extension and respond with a standard response rather than a nonstandard response. The call will continue as a standard H.324 type call. The Type II method does not require non-supporting terminals to handle the Type I method.

Preferably, the present invention provides a method for initiating a call between users with reduced call setup time while using one or more communication networks. The method includes transmitting a call signaling message from a first terminal to a second terminal through a network to initiate a call; once the call signaling message is received by the second terminal, the first terminal and Establishing a bearer channel between the second terminals. The method also includes determining a common mobile level for operation. The method provides one or more custom Non-Standard H.245 messages or custom Non-Standard fields in standard messages. The one or more custom nonstandard H.245 messages or custom nonstandard fields are associated with one or more setup parameters for an initial predetermined mode of operation. In addition, the method further comprises: transmitting from the first terminal to the second terminal, the one or more custom non-standard H.245 messages or custom non-standard fields in the standard message, and from the second terminal to the first terminal. Sending, to one terminal, a custom non-standard response message associated with the one or more custom non-standard H.245 messages or custom non-standard fields, and sending the one or more custom H.245 messages or custom non-standard fields for a predetermined time period. Processing. The method further includes establishing an initial predetermined mode of operation between the first terminal and the second terminal over the bearer channel based on at least one or more custom H.245 messages or custom non-standard fields. Include.

According to yet another embodiment, the present invention provides a computer readable recording medium containing instructions for initiating a call between users with reduced call set-up time using one or more networks. . The computer readable recording medium is provided between at least one pair of H.324 type terminals coupled to one or more networks. The computer-readable recording medium includes one or more instructions for transmitting a call signaling message from a first terminal to a second terminal through a network to initiate a call, and once the call signal is transmitted by the second terminal. When a message is received, one or more instructions for establishing a bearer channel between the first terminal and the second terminal, and one or more instructions for determining a common mobile level for operation. It includes. In addition, the computer-readable recording medium may include one or more custom Non-Standard H.245 messages or custom Non-Standard field in standard messages. Provide one or more commands to provide. The one or more custom nonstandard H.245 messages or custom nonstandard fields are associated with one or more setup parameters for an initial predetermined mode of operation. The computer-readable recording medium may also include one or more instructions for transmitting from the first terminal to the second terminal the custom non-standard H.245 message or a custom non-standard field in a standard message. One or more instructions for transmitting from the second terminal to the first terminal a custom nonstandard response message associated with the one or more custom nonstandard H.245 messages or a custom nonstandard field, and the one or more for a predetermined time. Contains one or more instructions for processing more custom H.245 messages or custom non-standard fields. In addition, the computer-readable recording medium may, based on at least one or more custom H.245 messages or custom non-standard fields, initiate an initial predetermined mode of operation between the first terminal and the second terminal over the bearer channel. It includes one or more commands to set.

Type III: Speed up by incorporating equipment options in the call signaling phase

A third method for shortening call setup time for H.324 terminals proposes to pass information during the call signaling phase (bearer setup) where it is possible to include user defined information in the bearer setup protocol. This method allows an H.324-type call facility to specify equipment options in media communications and in the basic configuration of multiplexers and logical channels. Representation of such choices, including choice codes (numeric strings representing predefined options properties or combinations of letters and numbers), and in the form of the ITU-T Abstract Syntax Technique (ASN.1) format. There are a number of ways to indicate explicit options. We will refer to these options as (coded or explicit) profiles. For explicit options or profiles, the list of profiles may be sent as part of a bearer setup signal or message. The profile (encoded or explicit) specifies the exact values for all aspects of the encoder and H.245 channels needed to set up the call. For example, Mobile Level, Master Slave Determination, Media Format for each Logical Channel, and Multiplexer Table Entry for each Logical Channel should be defined. The answering device selects the profile to use in the user defined information included in the bearer setup (call signal transmission) signal or message. This allows the terminals to exchange parameters of the H.245 channel when the called equipment accepts the call, rather than requiring multiple round trips after the call is accepted.

The bearer setup (call signal transmission) is usually specific to the network in which H.324-type equipment is used. For 3G-324M, call signaling uses an ITU-T Q931 type call signaling protocol that allows the integration of optional information messages. Q.931 allows the integration of user-defined information within protocol messages. Q.931 signaling can be complex, but can be simplified to two messages here for explanation. A "Setup" Q.931 message containing caller information and other parameters is sent from the calling equipment to the called terminal. The called terminal will respond with a "Connect" message to answer the call (eg, the user presses the answer button). Here, H.324 type equipment options are incorporated into the "Setup" message sent by the calling equipment. As described above, the optional messages can be incorporated into the customized portion of the Q.931 message. When the called terminal responds to the call by sending a "Connect" Q.931 message, it incorporates the preferred mode of operation into the user-defined area of the "Connect" response message. The setup and connection messages are described in more detail in ITU-T Q.931 Recommendations and 3GPP technical specification documents. 3GPP2 equivalent documents exist for the CDMA counterpart of WCDMA 3GPP.

For ISDN networks (eg, H.324 over ISDN) and networks signaled using the SS7 protocol, a similar structure to that described above for 3GPP can be used.

For GSTN networks, call signaling protocols such as V.8 and V.8bis can be extended to incorporate III selection codes.

The ability to use coded or explicit options overcomes the limitation of the amount of user-defined information that call signaling protocols can include in their messages or signals.

Preferably, the present invention provides a method for initiating a call between users with reduced call set-up time using one or more communication networks. The method may include one or more preferences for calls related to the first terminal (eg, handset, gateway, and other equipment) and the second terminal (eg, handset, gateway, and other equipment). Providing a). The one or more options relate to an initial mode of operation for the call between the first terminal and the second terminal. The method also includes processing the one or more options as a Custom Message (eg, customized based on the selection) and inserting the custom message in a predetermined field of a call initiation message. Including the step of including. The method transmits the custom message from the first terminal to the second terminal through a communication network using call signaling and processes the custom message at the second terminal. The method comprises the steps of: sending a custom response message by the second terminal using a call signaling response message to indicate to the first terminal the initial mode of operation and the initial mode of operation; Exchanging information between the first terminal and the second terminal after is set.

This method of incorporating equipment option modes of operation into call signaling can be used in conjunction with H.323 high-speed connections in H.324 / H.323 gateways that arbitrate calls between H.324 and H.323 equipment. Note that this is particularly effective. It is similarly effective when used in H.324 / SIP gateways that arbitrate calls between H.324 type and SIP equipment.

According to yet another embodiment, the present invention provides a computer readable recording medium containing instructions for initiating a call between users with reduced call set-up time using one or more communication networks. . The computer readable recording medium is provided between at least one pair of H.324 type terminals coupled to one or more communication networks. The computer-readable recording medium includes one or more instructions that provide one or more preferences for calls related to the first terminal and the second terminal. The one or more options relate to an initial mode of operation for the call between the first terminal and the second terminal. In addition, the computer-readable recording medium may include one or more instructions for processing the one or more options as a custom message, and the custom message in a predetermined field of a call initiation message. One or more instructions to include, and one or more instructions to transmit the custom message from the first terminal to the second terminal via a communication network using call signaling. The computer-readable recording medium may also include one or more instructions for processing the custom message at the second terminal, and a call signal transmission response message to indicate the initial mode of operation to the first terminal. one or more commands for sending a custom response message by the second terminal using a signaling response message, and one or more commands for exchanging information between the first terminal and the second terminal after the initial mode of operation has been established. It contains the above commands.

The objects, features and advantages of the present invention, which are believed to be novel, are particularly disclosed in the following claims. With respect to both its configuration and operation manner together with additional objects and advantages, the present invention will be best understood by reference to the following detailed description in conjunction with the accompanying drawings.

1A is a schematic diagram illustrating the communication between two terminals when an H.245 request message is sent from one terminal to another.

1B shows a Session Set-up for a call between H.324 type equipment. Note that in this case unidirectional video channels are used (e.g., image on adaptive layer AL2 of the H.223 multiplexer).

Figure 2 illustrates one embodiment of a method of using H.245 connected between two H.324 terminals to shorten connection time in H.324.

3 illustrates one embodiment of a method for using non-standard extension of H.245 messages to shorten connection time in H.324 calls.

4 illustrates one embodiment of a method of using bearer " user " information to shorten connection time in H.324.

FIG. 5 illustrates one embodiment of a method of using bearer " user " information to shorten connection time in a call between an H.324 terminal and an H.323 terminal using a gateway.

FIG. 6 shows one embodiment of an ASN.1 syntax description in a Type II Request.

FIG. 7 illustrates an embodiment of an ASN.1 syntax description in a Type II Response.

8 illustrates one embodiment of an ASN.1 syntax description in a Type III Request.

9 illustrates an embodiment of an ASN.1 syntax description in a Type III Response.

FIG. 10 illustrates one embodiment of several coded profiles and their description that may be used in a Type III request and response.

EXAMPLE

The present invention relates generally to communication technology. More specifically, the present invention meets other standards and recommendations related to or derived from such ITU-T H.324 Recommendations and 3G-324M Recommendations developed and adopted by the Third Generation Joint Projects (3GPP and 3GPP2). It provides a method for reducing the time required to establish a call between the terminals. More specifically, the present invention provides a method of (i) connecting H.245 messages that match the type and format of the medium and data to be exchanged and required to pass between terminals upon initiation to establish the capabilities of the two terminals. And apparatus, (ii) methods and apparatus for using non-standard H.245 messages or non-standard H.245 messages with non-standard fields to accelerate such setup, and (iii) inform each terminal of the capabilities of the other terminal, A method and apparatus for proposing the type and format of media and data exchanged by any user-defined field available in the call signaling protocol used for bearer setup prior to the start of step H.324. These methods can be used individually or several times to shorten the time it takes from when the user requests the establishment of a call to when the media exchange between terminals begins. By way of example only, the present invention relates to a 3G-324M multimedia hand in a packet network using a multimedia gateway that arbitrates protocols used between 3G-324M (H.324M based protocol) multimedia handsets in a mobile communication network and at each endpoint. Although applied to the setting of multimedia communication between a set and an H.323 based terminal, it should be noted that the present invention can be applied to a wider range.

The methods described above are generic and can be implemented in many other ways by those skilled in the art. The following embodiments are described to illustrate how they can be easily applied to a particular set of equipment requirements.

Type I Example:

In a particular embodiment of this concatenated H.245 message method, a terminal may transmit H.245 Request Terminal Capabilities (TCS) and Request Master Slave Determination (MSD) messages in one H.245. .245 Connect to PDU. The terminal also sends TCS and MSD response messages (Acks), Multiple Open Logical Channels (OLCs), and Multiplex Table Entry Send Requests (MES) into one H.245 PDU. Connect. Finally, the terminal combines the OLC and MES responses into a third H.245 PDU. The process of setting up an H.324 call between two terminals supporting this embodiment of the connection method is shown in FIG. As a result of this approach, the number of round trips required for call setup is reduced from about ten to three. This embodiment requires that MSDSE and CESE state machines can operate in parallel, and that multiple LCSE and MTSE state machines can operate in parallel. This embodiment is only one example of such a linked H.245 message method in the present invention; Other connections of messages may be configured; They may put other constraints on the signaling entity state machine within the implementation of H.245.

Optionally, the method also includes returning to normal operation if one of the terminals does not support Type I (ie, connected H.245 messages). In this case, the calling terminal recognizes that it has not received a response to the second of the connected H.245 messages. In this case, the calling terminal will attempt to return to each H.245 message in the SRP command frame and continue to retransmit the H.245 messages separately from the second message. There may be many other variations, alternatives, and modifications.

On the one hand, the method can also be applied to numbered simple retransmission protocols (SRP numbered versions, including SRP commands and sequences of SRP acknowledgment frames) and other similar variants. Of course, there can be many other variations, alternatives, and modifications.

Type II Example:

In a particular embodiment of the method using custom H.245 messages, non-standard capability is used. H.324 type equipment requires that the first H.245 message it sends is a Terminal Capability Set (TCS) message. The calling equipment includes the capability of the NonStandardParameter type of the TCS that it sends to the answering equipment. This capability is identified by a NonStandardIdentifier with a unique Object Identifier. This capability includes additional parameters required by the terminal called to initiate the call, which parameters are required for the MSD in the same way as required for standard H.245 operation. And Multiple Table Entry Descriptor (MTE) Descriptor. Figure 6 shows an example of an ASN.1 description that includes the syntax of all such data. By including this non-standard capability, the caller is required to accept the called party's decision as to which method to use and which channel to choose.

If the called equipment does not support this method, the calling equipment receives normal TCSAck and regular H.245 negotiation is used to continue the call set-up.

If the called equipment receives a TCS that includes a NonStandard capability associated with this method and itself supports the method, then the called equipment shall determine the terminalType value in the received non-standard capability. Master slave determination is performed by comparing with a value for a local terminal. The highest value will be chosen as the master. If the terminal type values are the same, the calling terminal will be selected as the master.

The called terminal will analyze the received capability table to determine the OpenLogicalChannel and multiple table entries for the new connection. If the called equipment cannot derive acceptable channel shapes or cannot accommodate the provided multipleEntryDescriptors, it will respond with a regular TCSAck. The rest of the call setup will be accomplished through regular H.245 negotiation.

If an acceptable channel shape and multiple table entries can be derived, the called party will replace the regular TCSAck with a H.245 ResponseMessage of type NonStandardMessage. See Figure 7 for an ASN.1 syntax description of the encoded data. The NonStandardIdentifier of a nonstandard response message will have the same object identifier as the nonstandard ability to identify this method.

Note that the called terminal does not include any additional or non-standard capabilities to the TCS it sends to the calling terminal, even if it supports this method. The calling terminal must wait until it receives either a TCSAck or a nonstandard message before processing.

The process of setting up an H.324 call between two terminals supporting this embodiment of the method using custom H.245 messages is shown in FIG. This embodiment provides 1.5 times less round trip exchange than the embodiment of the connected H.245 method.

Capability is indicated in the Terminal CapabilitySet request message. This ensures that the called terminal will not malfunction or stop when it is required to be able to handle cases where non-standard capabilities are being sent to the called terminal.

The second important aspect is that by inserting a custom message into the terminal capability set request message, the terminal sends a custom message of the first H.245 message and does not have to wait in this way after the mobility level is determined.

A third aspect is that a terminal capability set request, including type II messages included as non-standard capabilities, can be sent (with one or more H.245 messages) using type I mode.

The fourth aspect responds with an Ack message indicating to the calling terminal that the called terminal has selected one of the calling terminal's priority modes and, if the calling terminal has made some choices in the Type II message. Is that.

Type III Example:

In one embodiment of the method using call signaling "user" information, the Q.931 User-User Information Element is a SETUP and CONNECT. ) Used in PDUs. This information element shall be provided by the ASN.1 encoded structure (see Figure 8), including the terminalType (required by the MSD in the same way as required for standard H.245 operation), and by the calling terminal. Populated with a list of profiles. By including this element of information, the caller is required to accept the called party's decision as to whether this method is to be used and which profile will be selected.

Each profile describes a move level, multiple table entries, a logical channel used, and a codec used for each logical channel. 10 shows some examples of profiles. The profile contains all the information needed to immediately initiate a call and establish a medium between terminals without having to go through additional H.245 signaling after the bearer is set up.

If the called terminal does not support this method, the calling terminal receives the Q.931 CONNECT PDU without a user-user information element and the regular call setup is used.

If the called terminal receives a SETUP PDU containing a user-user information element associated with this method and itself supports the method, then the called equipment has a terminal type value in the received information element. A master slave determination is performed by comparing the terminal type value with a value for a local terminal. The highest value will be chosen as the master. If the terminal type values are the same, a technique such as selecting the calling terminal as the master can be used to resolve the conflict.

The called terminal will also select one of the provided profiles. If none of the provided profiles is appropriate, then no user-user information element is added to the Q.931 access PDU and the call proceeds normally.

If the profile is appropriate, the master slave decision is finished and the selected profile is encoded according to the ASN.1 syntax for response and added to the Q.931 access PDU as a user-user information element. 9 illustrates a particular embodiment.

The process of setting up an H.324 call between two terminals supporting this embodiment of the method using call signaling "user" information is shown in FIG.

Embodiments relating to H.324 / H.323 gateways:

Another embodiment illustrating the use of a gateway to an H.323 terminal using FastConnect is shown in FIG. 5. This embodiment can reduce call setup time to the maximum. This embodiment eliminates all round trip exchanges for H.245 messages, and for initial movement level detection for H.245 splitting.

Embodiments Regarding H.324 / SIP Gateways:

This embodiment is similar to that of an H.324 / H.323 gateway except that the gateway converts information (Type I, II, and / or III) into SIP signaling messages.

In addition, some terminals may support Type III and another terminal may support Type I / II. Just as the calling terminal does not receive a Type III response in the call signaling phase, both terminals must be able to operate with a common support type (ie, Type II in this case). The normal mode is for terminals to fall into the highest common mode, the highest supported version within that mode. Of course, there can be many other variations, alternatives, and modifications.

The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. Those skilled in the art will readily recognize that various modifications to these embodiments and that the generic principles defined herein may be applied to other embodiments without the use of creative capabilities. Thus, the present invention should not be limited to the specific embodiments described, but should be construed in the broadest scope consistent with the principles and novel features disclosed herein. For example, the functions may be combined or separated depending on the embodiment. Certain features can be added or removed. In addition, the specific order of the characteristics is specifically required in some embodiments, but may not be important in other embodiments. The series of processes may be executed in computer code and / or in hardware, depending on the embodiment. Of course, there can be many other variations, alternatives, and modifications.

In addition, the examples and embodiments described herein are presented for illustrative purposes only, and in view of these, various modifications and changes will be made to those skilled in the art and such modifications and changes are included within the spirit and scope of the present invention and the scope of the appended claims. Keep in mind that it should be.

Claims (44)

A method of initiating a call between users with reduced call set-up time using one or more communication networks, the method comprising at least one pair of H.324 type terminals coupled to one or more communication networks. Provided in between, Providing one or more preferences for calls related to the first terminal and the second terminal, wherein the one or more options are initial operating modes for the call between the first terminal and the second terminal. Related to; Treating the one or more options as a Custom Message; Including the custom message in a predetermined field of a call initiation message; Transmitting the custom message from the first terminal to the second terminal via a communication network using call signaling; Processing the custom message at the second terminal; Sending a custom response message by the second terminal using a call signaling response message to indicate the initial mode of operation to the first terminal; And Exchanging information between the first terminal and the second terminal after the initial mode of operation has been established. The method of claim 1, And the information includes voice and video. The method of claim 1, Wherein said one or more options relate to an ITU-T ASN.1 custom message. The method of claim 1, Wherein said one or more options are coded using a modulated signal. The method of claim 1, And the first terminal is an H.324 type gateway. The method of claim 1, And the second terminal is an H.324 type gateway. A method of initiating a call between users with reduced call set-up time using one or more communication networks, the method comprising at least one pair of H.324 type terminals coupled to one or more communication networks. Provided in between, Sending a call signaling message from a first terminal to a second terminal through a communication network to initiate a call; Establishing a bearer channel between the first terminal and the second terminal once the call signaling message is received by the second terminal; Determining a common mobile level for operation; Providing one or more custom Non-Standard H.245 messages or a custom Non-Standard field in standard message—the one or more custom H .245 message or custom non-standard field associated with one or more setup parameters for an initial predetermined mode of operation; Sending, from the first terminal to the second terminal, the one or more custom nonstandard H.245 messages or custom nonstandard fields in a standard message; Sending from the second terminal to the first terminal a custom nonstandard response message associated with the one or more custom nonstandard H.245 messages or custom nonstandard fields; Processing the one or more custom H.245 messages or custom non-standard fields for a predetermined time; And Establishing an initial predetermined mode of operation between the first terminal and the second terminal over the bearer channel based on at least one or more of the custom H.245 message or custom non-standard field. The method of claim 7, wherein Wherein the one or more custom non-standard H.245 messages represent an H.245 terminal capability set request message. The method of claim 7, wherein One or more user options, coded or explicit, are provided in one of the custom non-standard H.245 messages. A method of initiating a call between users with reduced call set-up time using one or more communication networks, the method comprising at least one pair of H.324 type terminals coupled to one or more communication networks. Provided in between, Sending a call signaling message from a first terminal to a second terminal through a communication network to initiate a call; Establishing a bearer channel between the first terminal and the second terminal once the call signaling message is received by the second terminal; Determining a common mobile level; Determining two or more H.245 messages associated with setup parameters for the initial predetermined mode of operation; Concatenating the two or more H.245 messages into one SRP command frame according to an SRP command frame of a predetermined size; Transmitting the SRP command frame including the two or more H.245 messages from a first terminal to a second terminal through a communication network; Sending the SRP acknowledgment message by the second terminal once the SRP command frame is received by the second terminal; Processing at least two or more H.245 messages for a predetermined time; And Establishing an initial predetermined mode of operation between the first terminal and a second terminal over the bearer channel. The method of claim 10, The movement level detection is carried out by H.324 baseline, also known as movement level 0, movement level 1, also known as ITU-T H.223 Annex A, movement level 2, also known as ITU-T H.223 Annex B, and ITU. -T H.223 Call initiation method performed according to any one selected from the set consisting of movement level 3, also known as Appendix C. The method of claim 10, Transmitting another SRP command frame containing two or more H.245 messages only after the SRP acknowledgment message has been received by the first terminal. The method of claim 10, The call setup time is reduced by at least 50% relative to the standard sequential exchange of individual H.245 messages. The method of claim 10, The H.245 message includes a terminal capability set request, a master slave determination request, an open logical channel request, and a multiple table entry definition request. call initiation method comprising one or more selected from among definitions requests. The method of claim 10, Wherein the first terminal is a handset, and the second terminal is equipment for providing an H.324 type terminal that is not a handset. The method of claim 10, Wherein the first terminal is a handset and the second terminal is a handset. The method of claim 10, If the terminal type value of the first terminal satisfies the condition equal to or higher than that of the second terminal, the first terminal acts as a master, and the second terminal is a slave. Call initiation method operating as). The method of claim 17, Wherein said condition is associated with a first SRP command frame. The method of claim 10, Exchanging audio and video information between the first terminal and the second terminal after the initial predetermined mode is set. The method of claim 10, Two or more concatenated messages are encoded using a common syntax. The method of claim 20, The common syntax is ITU-T ASN.1 Packaged Encoding Rules (PER). The method of claim 10, If the two or more connected messages are not processed by the second terminal, operating in an alternative normal mode. A computer readable recording medium containing instructions for initiating a call between users with reduced call set-up time using one or more communication networks. Provided between at least one pair of H.324 type terminals coupled to a communication network, One or more commands that provide one or more preferences for calls related to the first terminal and the second terminal, wherein the one or more options call the call between the first terminal and the second terminal. Related to an initial mode of operation for; One or more instructions for treating the one or more options as a Custom Message; One or more instructions for including the custom message in a predetermined field of a call initiation message; One or more instructions for transmitting the custom message from the first terminal to the second terminal over a communication network using call signaling; One or more instructions for processing the custom message at the second terminal; One or more instructions for sending a custom response message by the second terminal using a call signaling response message to indicate the initial mode of operation to the first terminal; And And one or more instructions for exchanging information between the first terminal and the second terminal after the initial mode of operation has been established. The method of claim 23, wherein And the information includes audio and video. The method of claim 23, wherein Wherein said one or more options are associated with an ITU-T ASN.1 custom message. The method of claim 23, wherein Wherein said one or more options are encoded using a modulated signal. The method of claim 23, wherein And the first terminal is an H.324 type gateway. The method of claim 23, wherein And the second terminal is an H.324 type gateway. A computer readable recording medium containing instructions for initiating a call between users with reduced call set-up time using one or more communication networks. Provided between at least one pair of H.324 type terminals coupled to a communication network, One or more instructions for sending a call signaling message from a first terminal to a second terminal through a communication network to initiate a call; One or more instructions for establishing a bearer channel between the first terminal and the second terminal once the call signaling message is received by the second terminal; One or more instructions for determining a common mobile level for operation; One or more commands that provide one or more custom Non-Standard H.245 messages or custom Non-Standard field in standard messages—the one or More custom H.245 messages or custom non-standard fields are associated with one or more setup parameters for an initial predetermined mode of operation; One or more instructions for transmitting from the first terminal to the second terminal the one or more custom nonstandard H.245 messages or a custom nonstandard field in a standard message; One or more instructions for transmitting from the second terminal to the first terminal a custom nonstandard response message associated with the one or more custom nonstandard H.245 messages or a custom nonstandard field; One or more instructions for processing the one or more custom H.245 messages or custom non-standard fields for a predetermined time; And A computer comprising one or more instructions for establishing an initial predetermined mode of operation between the first terminal and the second terminal over the bearer channel based on at least one or more custom H.245 messages or custom non-standard fields. Readable recording medium. The method of claim 29, And the one or more custom non-standard H.245 messages represent an H.245 terminal capability set request message. The method of claim 29, A computer-readable recording medium in which one or more user options, encoded or explicit, are provided in one of the custom non-standard H.245 messages. A computer readable recording medium comprising instructions for initiating a call between users with reduced call set-up time using one or more communication networks. Provided between at least one pair of H.324 type terminals coupled to a communication network, One or more instructions for sending a call signaling message from a first terminal to a second terminal through a communication network to initiate a call; One or more instructions for establishing a bearer channel between the first terminal and the second terminal once the call signaling message is received by the second terminal; One or more instructions for determining a common mobile level; One or more instructions for determining two or more H.245 messages associated with setup parameters for an initial predetermined mode of operation; One or more instructions for concatenating the two or more H.245 messages into one SRP command frame according to an SRP command frame of a predetermined size; One or more instructions for transmitting the SRP command frame including the two or more H.245 messages from a first terminal to a second terminal over a communications network; One or more instructions for sending an SRP acknowledgment message by the second terminal once the SRP command frame is received by the second terminal; One or more instructions for processing at least two or more H.245 messages for a given time; And And one or more instructions for establishing an initial predetermined mode of operation between the first terminal and the second terminal through the bearer channel. 33. The method of claim 32, The movement level detection is carried out by H.324 baseline, also known as movement level 0, movement level 1, also known as ITU-T H.223 Annex A, movement level 2, also known as ITU-T H.223 Annex B, and ITU. -T H.223 A computer readable recording medium carried according to any one selected from the set consisting of movement level 3, also known as H.223 Appendix C. 33. The method of claim 32, And transmitting another SRP command frame containing two or more H.245 messages only after the SRP acknowledgment message is received by the first terminal. 33. The method of claim 32, Said shortened call set-up time is at least 50% of a standard sequential exchange of individual H.245 messages. 33. The method of claim 32, The H.245 message includes a terminal capability set request, a master slave determination request, an open logical channel request, and a multiple table entry definition request. computer-readable recording medium containing one or more selected from definitions requests. 33. The method of claim 32, The first terminal is a handset, and the second terminal is a device providing an H.324 type terminal, not a handset. 33. The method of claim 32, And the first terminal is a handset and the second terminal is a handset. 33. The method of claim 32, If the terminal type value of the first terminal satisfies the condition equal to or higher than that of the second terminal, the first terminal acts as a master, and the second terminal is a slave. A computer-readable recording medium operating as). The method of claim 39, And the condition is associated with a first SRP instruction frame. 33. The method of claim 32, And exchanging audio and video information between the first terminal and the second terminal after the initial predetermined mode is set. 33. The method of claim 32, A computer-readable recording medium in which two or more connected messages are encoded using a common syntax. The method of claim 42, wherein And said common syntax is an ITU-T ASN.1 PER (Packed Encoding Rules). 33. The method of claim 32, And if the two or more connected messages are not processed by the second terminal, further comprising instructions for operating in an alternative normal mode.

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