Adaptive universal multiple access

• US 6,252,881 B1
• Filed: 10/29/1999
• Issued: 06/26/2001
• Est. Priority Date: 10/29/1999
• Status: Expired due to Fees

• Current Assignee: Iraida Ivanonvna Samoylenko, Norwood Living Trust
• Original Assignee: Elena Stanislavovna Samoylenko, Iraida Ivanonvna Samoylenko, Norwood Living Trust
• Inventors: Samoylenko, Stanislav Ivanovich
• Primary Examiner(s): Vu, Huy D.
• Application Number:
  US09/430,512
• Time in Patent Office: 606 Days
• Field of Search: 370/431, 370/433, 370/437, 370/438, 370/439, 370/442, 370/443, 370/444, 370/445, 370/446, 370/447, 370/449, 370/450, 370/451, 370/454, 370/468, 370/461, 370/400 , 370/408, 370/422, 709/223, 709/224, 709/225, 709/226, 709/227, 709/228, 709/229
• US Class Current: 370/433
• CPC Class Codes: H04L 12/40169 Flexible bus arrangements arrangements for maintenance or administration involving management of faults; events, alarms H04L41/06; automatic restoration of network faults H04L41/0654
• CPC Class Codes: H04L 12/4035 in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64

Abstract

An Adaptive universal multiple access (AUMA) apparatus and method for collision-free, high efficiency multiple access to a shared media uses a corrector to control access to ports in a hub. The corrector assigns each node an active or passive state and subdivides each transmission cycle into NA sub-cycles, where NA is the number of active nodes in the network. The corrector is configured so that each active node is accessed during one sub-cycle.

AUMA may be implemented in repeaters, head-ends, or network interface cards in wired, or wireless networks. To provide efficient utilization AUMA has several mechanisms of automatic adaptation to network topology, lengths of media, node activity, bursty traffic, and speed of transmission. AUMA is compatible with standard Ethernet and can be used in Ethernet environment, including mixed networks, where some nodes are UMA nodes, and the other are standard Ethernet nodes.

Claims

1. A hub apparatus for adaptive multiple access in a communication network having a plurality of nodes, each node including at least one port, comprising:

(a) a repeater;

(b) a corrector, said corrector comprising;

(i) a general server;

(ii) a plurality of port controllers, each said port controller having an access window controller for selecting the state of the access window to a port of the network; and

(iii) a logic circuit to assign each node an active or a passive state and to subdivide each transmission into cycles containing at least NA sub-cycles, where NA is the number of active nodes of the network; and

(c) an interface having a first set of links coupling said corrector to said interface, a second set of links coupling said repeater to said interface, and a third set of links coupling said interface to transceivers of the network;

wherein said hub is configured to select in each sub-cycle one of said active nodes to be accessed.

2. The apparatus of claim 1, wherein an active node contains data selected from the group consisting of data packets and control messages.

3. The apparatus of claim 2, wherein said corrector is configured to open in successive sub-cycles of each cycle access windows for an access period of time for each active node by sending an access window start signal.

4. The apparatus of claim 2, wherein each said port controller includes a current access number controller configured to calculate the current access number of a port when ports change their state.

5. The apparatus of claim 4, wherein each said port controller includes an access window controller for controlling the access window of the port controlled by said port controller.

6. The apparatus of claim 5, wherein said access window controller is configured to permit adaptation to variable network topology, variable node activity, bursty traffic, and variable channel length.

7. A method of adaptive multiple access in a communication tree network, comprising the steps of:

(a) providing a plurality of network nodes, each node of said plurality of nodes comprising at least one port, said nodes selected from the group consisting of stations and repeaters, each station comprised of one port being connected to said repeater, each repeater having at least two ports, and wherein said medium comprises a full-duplex channel between each pair of connected ports;

(b) providing at least one medium for the transmission of sessions between said ports, each said session comprising a sequence of at least one fragment, said fragments selected from the group consisting of data packets and control messages;

(c) assigning an active state to each of said nodes that has at least one session for transmission;

(d) assigning a passive state for each of said nodes that has no sessions for transmission;

(e) subdividing the transmission into cycles, each said cycle comprising of at least NA sub-cycles, where NA is a number of active nodes;

(f) selecting for each sub-cycle one active node to be accessed so that each active node is accessed in each cycle;

(g) permitting transmission of said sessions from the selected nodes. assigning a zero port in each repeater;

(h) creating a tree network of repeaters by connecting the zero ports of the repeaters to non-zero ports of other repeaters;

(i) connecting each said station to the vacant port of the repeaters;

(j) transmitting an initiating control message from all ports of the repeaters;

(k) assigning the repeater a master state if the repeater does not receive the initiative control message from the zero port;

(l) assigning the repeater a slave state if the repeater receives the initiating control message from the zero port;

(m) sequentially opening the ports of the master repeater for an access period of time;

(n) changing the master state of the repeater to the slave state if the repeater receives the session from the open port;

(o) retransmitting the receiving session to other ports of the repeater;

(p) changing the slave state of the repeater to the master state after the end of the receiving session;

(q) permitting transmission of said session from the state connected to the open repeater port; and

(r) transmitting a busy control signal from all non-open ports of said master repeater while the input of the open port is idle.

8. The method of claim 7 wherein during the access period the output of the open repeater port is idle.

9. The method of claim 7 wherein the duration of said access period is equal to at least the maximum roundtrip propagation delay of the network.

10. The method of claim 7 wherein the duration of said access period is equal to at least a roundtrip propagation delay of the channel between the repeater port and the node connected to the port, said roundtrip propagation delay of the channel determined by measuring a time interval between sending a control message from the repeater port to the connected node and receiving a response from the node.

11. The method of claim 7 wherein said busy control signal comprises a preamble of said data packet.

12. The method of claim 7 wherein said network comprises a head-end network, the plurality of nodes comprises a plurality of stations, and the media comprises an upward channel for transmitting from said stations to said head-end, and a downward channel for transmitting from the head-end to the stations with the head-end and the stations being connected both to the upward and downward channels.

13. The method of claim 12 further comprising the steps of:

at the head-end maintaining variables which store current information comprising the current states of said nodes;

opening in successive sub-cycles of each cycle access windows for an access period of time for each active station and, if NA<

N, for at least one passive station, providing each passive station being open at least once per at most N−

NA cycles, where N is the number of nodes in the network;

signaling the station having the open access window about the start of the access period by sending from said head-end to the station an access window start signal;

permitting the station during a predetermined start time after receiving the access window start signal to start transmitting the data packet;

changing the active state of the open active station to the passive state and decreasing NA by one, if the station does not start transmission of said session during the start time; and

changing the passive state of the open passive station to the active state, if the passive station starts transmission of said session during the start time.

14. The method of claim 13 wherein the duration of said access period is equal to at least the sum of a maximum roundtrip propagation delay of the network and the duration of said start time.

15. The method of claim 7 wherein the plurality of nodes comprises a plurality of said stations, and wherein the media comprises at least one bi-directional bus, each said station being connected to each bus.

16. The method of claim 15, further comprising the steps of:

assigning each node a unique initial access number, IAN, said IAN selected from the sequence of 0, 1, 2, . . . N−

1, where N is equal to the number of nodes in the network;

transmitting an initiating signal on the bus;

assigning each node said active state if the node has at least one packet for transmission while the initiating signal is being transmitted and assigning the node said passive state otherwise;

assigning each active node after transmitting the initiating signal a current access number, CAN equal to IAN;

maintaining at each node a variable associated with the number of active nodes, NA;

assigning NA equal to N after transmitting the initiating signal;

permitting transmission of said session from the active node, having CAN equal to zero;

decreasing the CAN of each active station after transmitting said session by another node;

assigning the CAN equal to NA−

1 at the station transmitted a session;

decreasing the CAN and NA by one at each active station after each idle interval of a predetermined duration; and

outputting the initiating signal from the passive node after appearance at least one session for transmission to the network.

17. The method of claim 16 wherein the duration of said idle interval is equal to at least the maximum roundtrip propagation delay of the network.

18. The method of claim 15 wherein said bi-directional bus comprises a plurality of bi-directional links, said links selected from the group consisting of wires, coaxial cables, intrachip connectors, wireless channels, optical channels, frequency division channels, time division channels, and infrared channels.

19. An apparatus for adaptive multiple access in a communication tree network, comprising:

(a) a plurality of nodes, each node comprising at least one port, said nodes selected from the group consisting of stations and repeaters, each station comprises one port being connected to said repeater, each repeater comprises of at least two ports, and wherein said medium comprises a full-duplex channel between each pair of connected ports;

(b) at least one medium for transmission of sessions between said ports, said session comprising a sequence of at least one fragment, said fragments selected from the group consisting of data packets and control messages;

(c) means for assigning each node an active state, if the node has at least one session for transmission;

(d) means for assigning each node a passive state, if the node has no sessions for transmission;

(e) means for subdividing the transmission into cycles, said cycle comprising of at least NA sub-cycles, where NA is a number of active nodes;

(f) means for selecting for each sub-cycle one accessing node to permit each active node to become the accessed node in each cycle; and

(g) means for permitting transmission of said session from the selected accessed nodes;

(h) means for assigning a zero port in each repeater;

(i) means for creating a tree network of repeaters by connecting the zero ports of the repeaters to not-zero ports of other repeaters;

(j) means for connecting each said station to the vacant port of the repeaters;

(k) means for transmitting an initiating control message from all ports of the repeaters;

(l) means for assigning the repeater a master state if the repeater does not receive the initiating control message from the zero port;

(m) means for assigning the repeater a slave state if the repeater receives the initiating control message from the zero port;

(n) means for sequentially opening the ports of the master repeater for an access period of time;

(o) means for changing the master state of the repeater to the slave state if the repeater receives the session from the open port;

(p) means for retransmitting the receiving session to other ports of the repeater;

(q) means for changing the slave state of the repeater to the master state after the end of the receiving session;

(r) means for permitting transmission of said session from the station connected to the open repeater port; and

(s) means for transmitting a busy control signal from all not-open ports of said master repeater while the input of the open port is idle.

20. The apparatus of claim 19, wherein said network comprises a head-end and said plurality of nodes of said head-end network comprises a plurality of stations, and wherein the media comprises an upward channel for transmitting from said stations to said head-end, and a downward channel for transmitting from the head-end to the stations, the head-end and the stations being connected both to the upward and downward channels.

21. The apparatus of claim 19, further comprising:

means for maintaining at the head-end variables which store current information comprising current states of said nodes;

means for opening in successive sub-cycles of each cycle access windows for an access period of time for each active station and, if NA<

N, for at least one passive station, providing each passive station being open at least once per at most N−

NA cycles, where N is the number of nodes in the network;

means for signaling the station having the open access window about the start of the access period by sending from said head-end to the station an access window start signal;

means for permitting the station during a predetermined start time after receiving the access window start signal start transmitting of the data packet;

means for changing the active state of the open active station to the passive state and decreasing NA by one, if the station does not start transmission of said session during the start time; and

means for changing the passive state of the open passive station to the active state, if the passive station starts transmission of said session during the start time.

22. The apparatus of claim 19 wherein the plurality of nodes comprises a plurality of said stations, and wherein the media comprising of at least one bi-directional bus, each said station being connected to each bus.

23. The apparatus of claim 19, further comprising:

means for assigning each node a unique initial access number, IAN, said IAN taking from the sequence of 0, 1, 2, . . . N−

1. where N is equal to the number of nodes in the network;

means for transmitting an initiating signal on the bus;

means for assigning each node said active state, if the node has at least one packet for transmission while the initiating signal being transmitted, assigning the node said passive state otherwise;

means for assigning each active node after transmitting the initiating signal a current access number, CAN, equal to IAN;

means for maintaining at each node a variable associated with the number of active nodes, NA;

means for assigning NA equal to N after transmitting the initiating signal;

means for permitting transmission of said session from the active node, having CAN equal to zero;

means for decreasing the CAN of each active station after transmitting said session by another node;

means for assigning the CAN equal to NA−

1 at the station transmitted a session;

means for decreasing the CAN and NA by one at each active station after each idle interval of a predetermined duration; and

means for outputting the initiating signal from the passive node after its appearance.