Routing system and method for a teleconferencing system

• US 5,654,961 A
• Filed: 05/22/1995
• Issued: 08/05/1997
• Est. Priority Date: 05/22/1995
• Status: Expired due to Fees

• Current Assignee: Initia, Inc. (York Telecom Corporation)
• Original Assignee: Madge Networks Inc.
• Inventors: Harmon, Michael, Araujo, Kenneth, Zhang, Siuling, Randall, Roderick, Bhatia, Rajiv
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US08/447,121
• Time in Patent Office: 806 Days
• Field of Search: 370/54, 370/58.1, 370/58.2, 370/58.3, 370/60, 370/62, 370/68.1, 370/79, 370/110.1, 379/93, 379/94, 379/96, 379/201, 379/202, 379/204, 379/205, 379/206, 379/269, 379/280, 379/284, 379/211, 379/212, 379/220, 379/271, 379/272, 348/13, 348/14, 348/15, 348/16
• US Class Current: 370/263
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15
• CPC Class Codes: H04M 7/00 Arrangements for interconnection between switching centres
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 2213/13091 CLI, identification of calling line
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/1324 Conference call
• CPC Class Codes: H04Q 2213/13292 Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13337 Picturephone, videotelephony

Abstract

In a networked videoconferencing system, a receiver with a number of receiving stations receives calls from a number of different calling stations. To get appropriate bandwidth, two calls are connected at the same time from the calling station to one of the receiving stations. The receiver includes an access switch that uses information from the calling station to pair calls together so that two calls from one calling station are routed to the same receiving station, regardless of the order in which the calls are received by the access switch. The access switch can use one or a combination of routing methods including storing all pairs of incoming numbers in a table and/or by using comparisons of similar numbers.

Claims

1. A method for routing calls in a system having a plurality of calling stations for calling a plurality of receiving stations over a switched network, wherein a calling station communicates with a receiving station through first and second calls connected at the same time, the method implemented by a switching system that routes calls from the switched network to the receiving stations, the method comprising the steps of:

(a) receiving a call originating from a calling station;

(b) determining whether there is an existing call currently connected from the calling station to a receiving station;

(c) if it is determined in step (b) that an existing call from the calling station is currently connected to a receiving station, routing the received call to the receiving station such that the received call and the existing call are thereby connected to the receiving station at the same time; and

(d) if it is determined in step (b) that no existing call from the calling station is currently connected to any one of the receiving stations, routing the received call to a receiving station that does not already have an existing call.

2. The method of claim 1, each calling station having a first and second identification number corresponding to a respective channel, step (a) including receiving one of the first and second identification numbers.

3. The method of claim 2, wherein, for at least some of the calling stations, the first and second identification numbers are different from each other, and wherein the switching system includes a first table, step (b) including a step of checking the first table to determine the other of the first and second identification numbers based on the received identification number.

4. The method of claim 3, wherein the switching system includes a second table relating the identification numbers of existing calls and the receiving stations to which such existing calls are connected, step (b) further including the step of checking the second table with the other of the first and second identification numbers to determine if a call with that other identification number has been routed in an existing call to a receiving station.

5. The method of claim 2, wherein, for at least one of the calling stations, the first and second identification numbers are identical, step (b) including determining whether an existing call having the identical identification numbers was routed to one of the receiving stations.

6. The method of claim 2, wherein step (b) includes determining whether the existing call has an identification number that is sufficiently similar within a defined threshold to the one of the first and second identification numbers of the received call.

7. The method of claim 6, further including a step of:

(e) storing in a table the one of the first and second identification numbers for the received call and the identification number for the existing call such that accessing one of the stored first and second identification numbers retrieves the other of the first and second identification numbers.

8. The method of claim 7, wherein step (e) is performed after it has been determined that the received call and the existing call have been connected for a period of time exceeding a threshold.

9. The method of claim 1, wherein the switching system receives calls made to different called directory numbers, the method further including the following steps after step (a) and before step (b):

(a1) determining from the called directory number whether to use a calling directory number when routing the received call; and

(a2) if it is determined that the calling directory number is to be used, proceeding to steps (b)-(d).

10. The method of claim 9, wherein step (a1) is performed by consulting a table having a list of called directory numbers and an associated list of routing methods.

11. The method of claim 1, further comprising the steps of:

(e) receiving another call from a different calling station;

(f) using a called directory number to determine whether steps (b)-(d) should be repeated for the call received in step (e); and

(g) routing the call to a particular receiving station associated with the called directory number without repeating steps (b)-(d).

12. A method for use in a system having a plurality of calling stations for calling a plurality of receiving stations over a switched network, wherein a calling station communicates with a receiving station through first and second calls connected at the same time, the method implemented by a switching system that routes calls from the switched network to the receiving stations, the method comprising the steps of:

(a) receiving a first call having a first identification number;

(b) receiving a second call having a second identification number;

(c) routing the first and second calls to a receiving station so that the first and second calls are connected to the receiving station at the same time;

(d) determining whether the first and second calls were received from the same calling station; and

(e) storing the first and second identification numbers in a storage element for future access in response to the determination in step (d), the storing being done such that the second identification number and the first identification number are linked so that by accessing the storage element with one of the first and second identification numbers, the other of the first and second identification numbers is retrieved.

13. The method of claim 12, wherein step (d) includes determining whether the first and second identification numbers are different within a certain threshold.

14. The method of claim 12, wherein step (d) includes determining whether the first and second calls are both connected to the receiving station for a minimum period of time.

15. The method of claim 12, wherein step (d) includes determining whether the first and second identification numbers are sufficiently close within a tolerance.

16. The method of claim 15, wherein the tolerance is based on a number of identical and different digits.

17. The method of claim 15, wherein step (d) includes determining whether the first and second calls are both connected to the receiving station for a minimum period of time.

18. The method of claim 12, wherein step (d) is performed after both the first and second calls are cleared.

19. The method of claim 12, further comprising the steps of:

(f) receiving a third call having a third identification number;

(g) accessing the storage element with the third identification number to obtain a fourth identification number;

(h) determining whether an existing fourth call with the fourth identification number is already connected to a receiving station; and

(i) routing the third call to the receiving station that the existing fourth call is connected to in response to a determination in step (h) that an existing fourth call has been routed.

20. The method of claim 12, further comprising the steps of:

(f) receiving a third call having a third identification number;

(g) accessing the storage element with the third identification number to obtain a fourth identification number;

(h) determining whether an existing fourth call with the fourth identification number is already connected to a receiving station; and

(i) routing the third call to a currently idle receiving station in response to a determination in step (h) that an existing fourth call has not been routed.

21. A receiver for receiving calls from a plurality of calling stations over a network in a system, transmissions between the calling stations and receiving stations being made through first and second calls at the same time, the receiver comprising:

a plurality of receiving stations; and

a switching system for receiving calls from the network and for routing the calls to the receiving stations, the switching system including;

a processor, responsive to a received call from a calling station, for determining whether there is an existing call from the calling station currently connected to a receiving station, and

a switch, controlled by the processor, for routing the received call to the same receiving station as the existing call in response to a determination that the existing call from that calling station is currently connected to a certain receiving station, and for routing the received call to an idle receiving station in response to a determination that a no existing call from the calling station is currently connected to any receiving station.

22. The receiver of claim 21, the switching system further including a storage element for storing a first table of information accessible by the processor, each call including an identification number indicating a channel, the identification numbers for at least some of the channels being stored in the first table, each calling station having associated identification numbers corresponding to respective first and second calls from the same calling station.

23. The receiver of claim 22, the processor including:

means for accessing the first table with an identification number of the received call to obtain an associated identification number, and

means for determining whether an existing call has the associated identification number.

24. The receiver of claim 21, the processor including:

means for comparing an identification number for the received call and identification numbers for existing calls,

the switch routing the received call to the receiving station that has an existing call with an identification number that is most similar to the identification number of the received call.

25. The receiver of claim 21, the processor including:

means for determining whether first and second calls are connected for a minimum threshold time, and

means for storing first and second identification numbers corresponding to respective first and second calls so that a second identification number can be determined from the first identification number,

the storing means being responsive to determining means determining that the first and second calls are connected for at least the minimum threshold time.

26. In a system having a plurality of calling stations for calling, over a switched network, a receiver having a plurality of receiving stations wherein a calling station communicates with a receiving station through first and second calls at the same time, a switching system for the receiver comprising:

means for routing first and second calls to a receiving station;

a processor for determining whether the first and second routed calls originated with the same calling station after the calls have already been routed; and

a storage element, coupled to the processor, for storing the first and second identification numbers in response to the determination by the processor, the storing being done such that the second identification number and the first identification number are linked so that by accessing the storage element with one of the first and second identification numbers, the other of the first and second identification numbers is retrieved.

27. The switching system of claim 26, wherein the processor has means for determining whether the first and second calls are both connected for a minimum period of time.

28. The switching system of claim 26, wherein the processor has means for determining whether the first and second identification numbers are similar within a certain tolerance.

29. The switching system of claim 26, wherein the processor has means for determining whether the first and second identification numbers are different within a certain tolerance.