KR100270710B1 - Concurrent multicasting using atm technology - Google Patents

Abstract

PURPOSE: A simultaneous multi casting transfer network using an ATM technique and simultaneous transfer method thereof is provided to simultaneously transmit information from plural end users by providing an ATM network comprising plural virtual path identifiers(VPIs) or a virtual path identifier/virtual circuit identifier(VPI/VCI) assigned to each end user who participates in multipoint-multipoint two-way multicast connection. CONSTITUTION: Plural end users communicate information to each other. Plural ATM identifiers are related to the information communicated among the plural end users and each end user, and identifies the end user transmitting the information among the end users so that the end user simultaneously receives the information transmitted from the plural end users.

Description

Simultaneous Multicasting Transmission Network and its Simultaneous Transmission Method Using Asynchronous Transmission Mode Technology

The present invention relates generally to an asynchronous transfer mode (ATM) network, and more particularly, to an ATM network and a method for simultaneously transmitting information from a plurality of end users.

Asynchronus Transfer Mode (ATM) is a fast packet / cell switching technique used to transmit audio signals, data signals, video signals, and video signals. All broadband transmissions, whether audio, video or video, are divided into a series of fixed-length 53-byte cells and are routed through an ATM network connected by an ATM switch. The following lists some of the ATM benefits.

a) Provide bandwidth on demand (by using only as much bandwidth as necessary).

b) Provide a large amount of information transfer (switching) capacity.

c) Basically asynchronous, allowing statistical multiplexing of information streams.

d) an ideal information transmission medium for multimedia applications.

e) Ideal for virtual circuit connections (so providing many connections per physical connection layer).

ATM is a connection-oriented protocol. That is, the virtual connection between end users must be set up before the end users send information to each other. The connection oriented protocol is compared to the connectionless oriented protocol, and a temporary virtual connection is established on demand when information needs to be transmitted.

ATM can be used to set up a point-point virtual connection, a point-multipoint virtual connection or a multipoint-multipoint virtual connection. Point-to-point connections can be unidirectional (half duplex) or bidirectional (full duplex). In one-way case, only one end user transmits the information and the other end user can receive it. In addition, in the case of bidirectional (full duplex communication), two end users can transmit and receive information. Point-multipoint connections are generally one-way and are used to simultaneously transmit information from one source end user to multiple destination end users. Multipoint-to-multipoint connections are typically used for conferencing purposes (similar to conferencing telephony), and for all end users, allowing end users to send as well as receive information.

ATM technology is based on standard 53-byte ATM cells. The first five bytes carry the control information and are referred to as the "header" of the ATM cell. The remaining 48 bytes carry user information or payload. For additional information on ATM technology, see the ITU-T or ATM Forum Standards.

Two important elements in the header of an ATM cell are known as "Virtual Path Identifier" and "Virtual Circuit Identifier". These are abbreviated as VPI and VCI, respectively. The virtual path identifier or virtual path identifier / virtual circuit identifier "identifies" the ATM cell (ie, the cell's address) together, the two most important uses of which are:

a) Uniquely identifies an ATM cell on an existing physical medium.

b) Determine the "routing" of the cell inside the ATM switch or router.

The methods used for uniquely identifying one cell as well as the method used for routing one cell in one switch or router are described in detail in the aforementioned standards.

Current ATM networks are not equipped so that all end users participating in a multipoint-to-multipoint ATM connection can transmit information in full duplex (bidirectional). In addition, in a manner that enables an information recipient to determine what information is transmitted, there is no method or solution that can be used to achieve simultaneous transmission of information. Typical ATM networks are limited to point-multipoint, one-way connections, where there is one "sending" user and multiple "receiving" users. In an ATM network with a point-multipoint connection set up for a bidirectional connection, a return path from the receiver to one transmitting user (sender) is used to transmit the low band control information.

As described above, high-band information cannot be transmitted simultaneously in a multipoint-multipoint bidirectional connection of a conventional ATM network. This limits the use of an ATM network in applications where multiple users simultaneously send and receive video, image or data information to compare and collate such information. For example, the use of the ATM network is a medical device in which the transmitter of the information can be located elsewhere on earth or in space and the receiver of the information can compare / contrast images, video signals (pixels) in real time (or near real time). Applied in technology and space technology.

1 shows a conventional ATM network 10 having three end users A 20, B 30 and C 40, where only one user can transmit information at a given time, while the other end user Information may be received (eg, other end users B 30 and C 40 receive while end user A 20 transmits). Only one user can transmit information because each end user is assigned a single VPI (Virtual Path Identifier) or VPI / VCI (Virtual Path Identifier / Virtual Channel Identifier).

User A 20 sends information using VPI _A and VPI / VCI _A, which information is received by User B 30 on VPI _B or VPI / VCI _B and by User C 40 on VPI _C and VPI / VCI _C. do. If two users A 20 and C 40 send information at the same time, user B 30 cannot determine the source of such information, which means that user A 20 and user through the same VPI _B or VPI / VCI _B Because it is received from C 40.

Thus, there is a need for an ATM network and method for simultaneously transmitting information (data, video or video) from multiple users in a multipoint-multipoint bidirectional ATM connection.

Accordingly, the present invention provides a plurality of end users for communicating information between a plurality of end users; And identifying end users that have transmitted information among the end users associated with each end user and information to be communicated between the end users, such that the end user can simultaneously receive information sent from a plurality of end users. It provides an asynchronous transmission mode (ATM) network comprising a plurality of identifiers for.

The present invention further provides a method for simultaneously transmitting information from a plurality of end users in an ATM network. The transmitting method comprises maintaining the plurality of end users to communicate information between them; And a plurality of ATM identifiers for identifying one of the end-users that has transmitted the information among the end-users so that the end-user can simultaneously receive information transmitted from a plurality of end-users. It comprises a step assigned to the user.

In addition, the present invention provides a plurality of end users for communicating information between a plurality of end users; And a plurality of virtual connections associated with each end user and the information to be communicated between them, thereby transmitting end of information among the end users such that the end user can simultaneously receive information sent from a plurality of end users. Each virtual connection is identified by one or more ATM identifiers to identify a user.

One advantage of the present invention is to conserve resources within individual ATM switches and network link bandwidths.

Another advantage of the present invention is simultaneous multicasting for a single multipoint-multipoint ATM network connection.

Another advantage of the present invention is the conservation in VPI / VCI allocation and bandwidth availability.

Another advantage of the present invention is that the ATM Network Management System maintains only one logical network connection, thus conserving resources used in the ATM Network Management System.

1 shows a conventional Asynchronous Transfer Mode (hereinafter referred to as "ATM") network with three end users.

2 illustrates an ATM network according to the present invention.

3 is a detailed view of the ATM network of FIG. 2 in accordance with the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention generally relates to an ATM network having a plurality of virtual path identifiers (VPIs) or virtual path identifiers / virtual line identifiers (VPIs / VCIs) assigned to each end user participating in a multipoint-multipoint bidirectional multicast connection. To provide. The invention discloses, by way of example, an ATM network 100 having three end users (end user A 50, end user B 52, and end user C 54), as shown in FIG. The three end users (A 50, B 52, C 54) are three different users using the three separate User-to-Network Interfaces (UNs) (A 70, B 72 and C 74). End of ATM switching nodes (Node A 60, Node B 62, Node C 64). The user-network interfaces A 70, B 72 and C 74 are connected to node A 60, node B 62 and node C 64, respectively. Network Management System (NMS), which is a permanent virtual circuit (PVC) showing each end user A 50, B 52, and C 54 assigned to three virtual path identifiers or virtual path identifiers / virtual line identifiers ( 80) the connection between end users A 50, B 52 and C 54 is established and controlled. One of these virtual path identifiers or virtual path identifiers / virtual line identifiers is used to transmit the information, while the other two are used to receive the information. In the prior art, network management system 80 controls the assignment of each virtual path identifier and virtual path identifier / virtual circuit identifier to each end user.

The network management system 80 transmits commands for establishing and controlling a connection to each of three nodes A 60, B 62, and C 64 to simultaneously multicast information between end users A 50, B 52, and C 54. Set up one logical connection for Referring to Figure 3, as follows.

At node A 60, VPI / VCI ′ _B1 120 is the same as VPI / VCI ′ _B2 110, and VPI / VCI ′ _C1 140 is the same as VPI / VCE ′ _C2 130.

At node B 62, VPI / VCI ' _A1 160 is the same as VPI / VCI' _A2 150 and VPI / VCI ' _C1 180 is the same as VPI / VCE' _C2 170.

At node C 64, VPI / VCI ′ _B1 190 is the same as VPI / VCI ′ _B2 200, and VPI / VCI ′ _A1 210 is the same as VPI / VCE ′ _A2 220.

This is shown by the following sample values.

At node A 60, VPI / VCI _A (145) is 0/32, VPI / VCI ' _B1 (120) is 0/33, VPI / VCI' _C1 (140) is 0/34, and VPI / VCI ' _B2 110 is 0/33 and VPI / VCI ' _C2 130 is 0/34.

At node B 62, VPI / VCI _B (185) is 1/32, VPI / VCI ' _A1 (160) is 0/33, VPI / VCI' _C1 (180) is 0/35, and VPI / VCI ' _A2 150 is 0/33 and VPI / VCI ' _C2 170 is 0/35.

At node C 64, VPI / VCI _C (215) is 2/32, VPI / VCI ' _B1 (190) is 0/35, VPI / VCI' _A1 (210) is 0/34, and VPI / VCI ' _B2 200 is 0/35 and VPI / VCI ' _A2 220 is 0/34.

It will be appreciated that the particular node connection and the value given to the aforementioned virtual path identifier / virtual line identifier are examples only. In some arrangements of an ATM network, users A 50, B 52, and C 54 may be interconnected through tandem or relay ATM switches or nodes. In such a case, the value assigned to the virtual path identifier / virtual line identifier need not be as previously shown. These separate network configurations are still within the scope of the present invention.

At node A 60, an incoming ATM cell with header addresses 0/33 is output to user-network interface A 70 with address 0/33 as a point-point connection. Also, the incoming ATM cell with header addresses 0/34 is output to the user-network interface A 70 as a point-point connection. In other words, this is not one merged connection, but two point-to-point connections between the Network-to-Network Interface (NNI) B 82 and the User-Network Interface A 70. This is possible with ATM because there are two directions of cell transmission paths (i.e., from user-network interface A 70 to network-network interface B 82, and from network-network interface B 82 to user-network interface A 70). This is because there is a separate header translation table.

Thus, the end user A 50 has three header addresses assigned. That is, from address 0/32 for transmitting cells to nodes B 62 and C 64, from address 0/33 for receiving cells from user B 52 connected to node B 62, and from user C 54 connected to node C 64. Has header address 0/34 for receiving the cell.

The same applies to user B 52. The user transmits a cell with header addresses 1/32 and receives a cell with header addresses 1/33 and 1/35.

The same applies to user C 54. The user C 54 transmits a cell with header addresses 2/32 and receives a cell with header addresses 2/34 and 2/35.

This example shows that the incoming cell header address of each network-to-network interface (A 80, B 82 and C 84) does not need to be wasted, since three separate one-way multicast connections are established and the same It will be the case if you get the effect. Examples are the following addresses: addresses 0/33, 0/34 on node A 60, addresses 0/33, 0/35 on node B 62, and addresses 0/34 and 0/35 on node C 64.

In a multicast connection involving N users, where N≥3 and each user is assigned N virtual path identifiers or virtual path identifiers / virtual line identifiers, one point-multipoint physical connection and N-1 Point-to-point physical connections exist for each end user. As a result of these multiple virtual path identifiers or virtual path identifier / virtual circuit identifier assignments, each user may simultaneously transmit and / or receive information while maintaining cell sequence integrity. Cell sequence integrity is maintained because the cell received from each user (sender) has a "unique" virtual path identifier / virtual line identifier address in the cell header.

The bandwidth used in the ATM network 100 of the present invention is smaller than the bandwidth when three separate multicast connections are set up because the return bandwidth is fully utilized. In the case of three separate connections, the return bandwidth is wasted because such connections are three independent bidirectional connections.

In addition, there are many operations managements involved in the case of three independent connections because the operations management all belong to the same "session", and as a result, the network management system stores a plurality of stored information in the database. It must be maintained at, and must have a lot of intelligence to correlate the three separate connections. It is not necessary to do this in the network management system of the present invention, because from an operational management point of view, it is a single logical connection. There are three separate connections inside each node to support these logical connections; One point-multipoint physical connection exists to transmit an ATM cell, and two point-point physical connections exist to receive an ATM cell where N = 3, that is, three end users.

Thus, in the reverse direction of each multipoint connection, the virtual path identifier / virtual line identifier and bandwidth are fully utilized in the present invention.

These advantages will be doubled when many users N are connected via a simultaneous multicast connection.

While the invention has been shown and described with reference to specific embodiments, embodiments other than those specifically described may be realized or practiced without departing from the scope and spirit of the invention as defined by the appended claims. It will be understood by those skilled in the art that various modifications may be made to the invention.

Claims (39)

In the asynchronous transfer mode (ATM) network, The plurality of end users for communicating information between the plurality of end users; And Identifying the end user that sent information among the end users associated with the respective end user and information to be communicated between the end users, such that the end user can simultaneously receive information sent from a plurality of end users. Asynchronous transmission mode network, characterized in that it comprises a plurality of ATM identifiers for. The method of claim 1, And a logical connection to join the end-users. The method of claim 2, And the logical connection is maintained in a network management system (NMS). The method of claim 2, And wherein said logical connection is maintained as a permanent virtual circuit. The method of claim 1, The number of end users is N, where N is an integer greater than or equal to 3, and N in the ATM identifier is associated with each of the end users. The method of claim 5, And N physical connections for each of the end users to join the N end users. The method of claim 6, And said N physical connections comprise one point-multipoint physical connection and N-1 point-point physical connections. The method of claim 7, wherein Wherein said point-multipoint physical connection is used to transmit information to a plurality of end users, wherein said point-point physical connection is used to receive information from a plurality of end users. The method of claim 6, And said N physical connections are formed at an ATM switch. The method of claim 1, And wherein the information communicated between the end users is in the form of an ATM cell. The method of claim 10, And wherein said ATM cell includes one or more of said ATM identifiers. The method of claim 1, And wherein the ATM identifier comprises a virtual path identifier (VPI). The method of claim 1, And said ATM identifier comprises a virtual circuit identifier (VCI). In the method for transmitting information from a plurality of end users at the same time in an asynchronous transmission mode network, Maintaining a plurality of end users to communicate information between them; And Information to be communicated between the end users and each of the end users is provided with a plurality of ATM identifiers for identifying among end users that have transmitted information among the end users such that the end users can simultaneously receive information sent from a plurality of end users. A method comprising a step assigned to a user. The method of claim 14, And maintaining a logical connection to join the end user. The method of claim 15, The logical connection is maintained in a network management system (NMS). The method of claim 15, The logical connection is maintained in a network management system. The method of claim 14, Maintaining the plurality of end users includes maintaining N of the end users, where N is an integer greater than or equal to 3, and wherein the assigning step comprises N number of the ATM identifiers assigned to each of the end users. The method comprising the step of assigning. The method of claim 18, And maintaining N physical connections for each of said end users for joining said N end users. The method of claim 19, And wherein said N physical connections comprise one point-multipoint physical connection and N-1 point-point physical connections. The method of claim 20, The point-multipoint physical connection is used to transmit information to a plurality of end users, wherein the point-point physical connection is used to receive information from the plurality of end users. The method of claim 19, And wherein said N physical connections are formed at an ATM switch. The method of claim 14, And wherein the information communicated between the end users is in the form of an ATM cell. The method of claim 23, wherein And wherein said ATM cell includes one or more of said ATM identifiers. The method of claim 14, The ATM identifier comprises a virtual path identifier. The method of claim 14, The ATM identifier comprises a virtual circuit identifier. In the asynchronous transmission mode network, The plurality of end users for communicating information between the plurality of end users; And Identifying the end user that sent information among the end users associated with the respective end user and information to be communicated between the end users, such that the end user can simultaneously receive information sent from a plurality of end users. And a plurality of virtual connections, each identified by one or more ATM identifiers for the asynchronous transmission mode network. The method of claim 27, And a logical connection to join the end-users. The method of claim 28, And said logical connection is maintained in a network management system. The method of claim 28, And the logical connection is maintained as a permanent virtual circuit. The method of claim 27, The number of end users is N, where N is an integer greater than or equal to 3, and N in the ATM identifier is associated with each of the end users. The method of claim 31, wherein And N physical connections for each of the end users to join the N end users. The method of claim 32, And said N physical connections comprise one point-multipoint physical connection and N-1 point-point physical connections. The method of claim 33, wherein Wherein said point-multipoint physical connection is used to transmit information to a plurality of end users, wherein said point-point physical connection is used to receive information from a plurality of end users. The method of claim 32, And said N physical connections are formed at an ATM switch. The method of claim 27, And wherein the information communicated between the end users is in the form of an ATM cell. The method of claim 36, And wherein said ATM cell includes said at least one ATM identifier. The method of claim 27, And wherein said at least one ATM identifier comprises a virtual path identifier. The method of claim 27, And wherein said at least one ATM identifier comprises a virtual circuit identifier.