Multiplex communications – Data flow congestion prevention or control – Control of data admission to the network
Reexamination Certificate
1998-09-28
2001-11-13
Ngo, Ricky (Department: 2664)
Multiplex communications
Data flow congestion prevention or control
Control of data admission to the network
C370S400000, C370S460000, C370S468000
Reexamination Certificate
active
06317415
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to information networks, and more particularly to a method and system for communicating information in a network.
BACKGROUND OF THE INVENTION
Communication devices such as telephones, computers, and video equipment may be interconnected to form a network. A network allows multiple parties to communicate with each other. Communications within a network often take the form of voice, data, video, or a combination of these forms. Such communications allow for meetings and presentations with participants separated by long distances. These events depend on the network to function as quickly and accurately as possible, in order to compensate for the distance of the participants.
A network may be formed by linking independent communication devices together according to a protocol. One example of a protocol for linking communication devices is Fibre Channel. In a Fibre Channel network, each device, acting as a node, or entry point onto the network, transmits and receives information through the network to the other network nodes. Although Fibre Channel networks may take various forms, a loop topology is often incorporated. In a loop topology, network nodes are connected in loop arrangement with any given node directly connected to only its two neighbors. In this manner, communication between all parties connected to the network is possible. One advantage of the some loop topologies is fault tolerance. In some implementations that utilize counter-rotational rings, if a break between nodes occurs, information may be routed back around the loop to its destination.
Information transmitted by the nodes travels around the loop until it reaches its destination. Traditionally, many Fibre Channel networks are configured to allow transmission of information by only one node at a given time. Thus, while any given node is transmitting information, all other nodes can only receive information. In addition traditional networking protocols do not specify the amount of time that this one node can transmit. Such communication schemes pose problems with the transmission of isochronous data that require the transfer of data at regular intervals such as live video and audio. A node that has live video to transfer is threatened with data loss if the network is currently servicing an unbounded transfer for another node. This problem is enhanced when the network has multiple sources of live isochronous data.
SUMMARY OF THE INVENTION
Accordingly, a need has arisen for an improved method and system for communicating information in a network. The present invention provides a method and system for communicating information in a network that addresses shortcomings of prior systems and methods.
According to one embodiment of the invention, a method for communicating information in a network having a plurality of nodes includes designating one of the plurality of nodes as a master node. The method also includes scheduling, by the master node, periodic transmission of a frame that has a plurality of slots. The method also includes receiving, at a first node of the plurality of nodes, the frame and determining which slots of the frame that are accessible to the first node. The method further includes accessing, by the first node, a slot that is determined to be accessible by the first node.
According to another embodiment of the invention, a communications system includes a plurality of network nodes including a first node comprising an interface unit. The interface unit includes a scheduler operable to schedule periodic transmission of a plurality of frames at respective designated times. Each of the plurality of frames includes a plurality of slots. The interface unit also includes an access system operable to designate which of the plurality of slots of a frame are accessible by the first node and to access the designated slots.
Embodiments of the invention provide numerous technical advantages. For example, in one embodiment of the invention, a plurality of users can transmit and receive information simultaneously rather than only one user being able to transmit at a time. Such communication allows synchronization of data from a plurality of sources, such as in videoconferencing. Furthermore, the network of the present invention allows transmission of information at both periodic rates and at aperiodic rates. Thus, user data that requires on-time delivery may be transmitted according to a periodic schedule and system data that does not require on-time delivery may be transmitted periodically when bandwidth is available. This sharing of bandwidth by both asynchronous and isochronous transmission types allows more cost-effective use of bandwidth. Furthermore, this sharing may be accomplished within a single network rather than requiring a plurality of different networks.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.
REFERENCES:
patent: 3924245 (1975-12-01), Eaton et al.
patent: 4482999 (1984-11-01), Janson et al.
patent: 4835770 (1989-05-01), Hayano
patent: 5257259 (1993-10-01), Tsurumi
patent: 5301185 (1994-04-01), Cherry
patent: 5303230 (1994-04-01), Hishida et al.
patent: 5305314 (1994-04-01), Edblad et al.
patent: 5317572 (1994-05-01), Satoh
patent: 5375233 (1994-12-01), Kimber et al.
patent: 5428819 (1995-06-01), Wang et al.
patent: 5502719 (1996-03-01), Grant et al.
patent: 5519690 (1996-05-01), Suzuka et al.
patent: 5598541 (1997-01-01), Malladi
patent: 5602852 (1997-02-01), Shiobara
patent: 5610914 (1997-03-01), Yamada
patent: 5610921 (1997-03-01), Christensen
patent: 5644761 (1997-07-01), Yoder et al.
patent: 5664224 (1997-09-01), Davis
patent: 5737743 (1998-04-01), Ooe et al.
patent: 5748629 (1998-05-01), Caldara et al.
patent: 5761430 (1998-06-01), Gross et al.
patent: 5768043 (1998-06-01), Nemazie et al.
patent: 5796720 (1998-08-01), Yoshida et al.
patent: 5828402 (1998-10-01), Collings
patent: 5835087 (1998-11-01), Herz et al.
patent: 5862136 (1999-01-01), Irwin
patent: 5924112 (1999-07-01), Barber et al.
patent: 5938747 (1999-08-01), Young
patent: 5963982 (1999-10-01), Goldman
patent: 5978578 (1999-11-01), Azarya et al.
patent: 5983293 (1999-11-01), Murakami
patent: 5991847 (1999-11-01), Ballard et al.
patent: 5999634 (1999-12-01), Abbott et al.
patent: 6041060 (2000-03-01), Leichty et al.
patent: 6044091 (2000-03-01), Kim
patent: 2 232 696 A (1998-11-01), None
patent: 0 256 681 (1987-07-01), None
patent: 0 621 704 A1 (1993-04-01), None
patent: 0 724 344 A2 (1996-07-01), None
patent: 0 855 818 A2 (1998-01-01), None
patent: 0 632 625 A1 (1995-01-01), None
patent: 0 876 075 A2 (1998-11-01), None
patent: 06 326721 (1995-03-01), None
S. Cavalieri, et al, Abstract “Scheduling Transmissions in Time-Critical Distributed Systems,” Universita' di Catania—Facolta' di Ingegneria Instituto di Informatica e Telecommunicazioni, IEEE, pp. 541-456, 1995.
PCT International Search Report dated Jan. 26, 2001 for PCT/US99/21722 filed Oct. 21, 1999.
Lin Y-S, et al., “Queue Management for Shared Buffer and Shared Multi-Buffer ATM Switches” Proceedings of Infocom, US, Los Alamitos,IEEE Comp. Soc. Press., vol. Conf. 15 (pp 688-695), 1996.
“Protocol for Isochronous Traffic Over Fiber channel Switching”IBM Technical Disclosure Bulletin, US, IBM Corp. NY, vol. 37 No. 06B (pp 377-380), Jun. 1994.
Malavalli, “High Speed Fibre Channel Switching Fabric Services,”SPIE, vol. 1577 (pp 216-226), 1991.
PCT International Search Report dated Jan. 26, 2000 for PCT/US99/21714 filed Sep. 21, 1999.
PCT International Search Report dated Feb. 24, 2000 for PCT/US99/21722 filed Sep. 21, 1999.
PCT International Search Report dated Mar. 10, 2000 for PCT/US99/21648 filed Sep. 21, 1999.
PCT International Search Report dated Mar. 2, 2000 for PCT/US99/21721 filed Sep. 21, 1999.
Darnell B. Scott
Jennings William T.
Lengel Bradley D.
Reddy Praveen S.
Baker & Botts L.L.P.
Ngo Ricky
Raytheon Company
LandOfFree
Method and system for communicating information in a network does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for communicating information in a network, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for communicating information in a network will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2585770