Inband dynamic port allocation

• US 4,893,305 A
• Filed: 03/31/1988
• Issued: 01/09/1990
• Est. Priority Date: 03/31/1988
• Status: Expired due to Fees

• Current Assignee: Racal-Datacom, Inc. (Thales SA)
• Original Assignee: Racal Data Communications Incorporated
• Inventors: Urbieta, Ignacio Jr., Fernandez, Raul F.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Chin, Wellington
• Application Number:
  US07/175,871
• Time in Patent Office: 649 Days
• Field of Search: 370/84, 370/95, 370/89, 370/31, 370/29, 370/24, 375/7, 375/8
• US Class Current: 370/254
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers

Abstract

A multi-port (multiplexed) modem for implementing automatic reconfiguration of the ports so that transmission bandwidth can be optimized. The modem utilizes a sequence of communications and acknowledgments transmitted over the donor port donating the bandwidth and the recipient port receiving the bandwidth. This allows reconfiguration of the modem ports without need for interruption of the unaffected ports and requires no secondary channel to implement. Only the port going idle and the port receiving the bandwidth are affected so that communication channel throughput is maximized and unaffected ports are not interrupted.

Claims

1. In a multi-port modem, a method of allocating bandwidth from a donor port which is idle to a recipient port which is to have its bandwidth allocation increased without interrupting other ports in said modem, said multi-port modem being of the kind that transmits and receives data to and from a plurality of ports including said donor and recipient ports over a transmission medium using time division multiplexing so that each port uses one or more time slots for data transmission, and wherein the data are transmitted over said transmission medium, the method comprising the steps of:

transmitting a code over said donor port time slot to signify that said donor port is idle;

coordinating a change in transmission rate of said recipient port by transmitting a handshaking protocol over the time slots of said idle donor port and said recipient port; and

reconfiguring said multi-port modem to allocate the bandwidth of said donor port to said recipient port without interruption of said other ports.

2. The method of claim 1, wherein said coordinating step further comprises the steps of:

transmitting a drop code over said donor port to signal that said donor port is donating its time slot;

transmitting a multiplexer configuration code over said donor port to specify a new multiplexer configuration;

transmitting a synchronization code over said donor port to synchronize reconfiguration of said other ports if required; and

transmitting an upcode to signal a start of transmission using said new multiplexer configuration over said donor and recipient ports.

3. The method of claim 2, wherein the step of transmitting said drop code includes the step of transmitting a simulated RTS or DTR code followed by transmitting a code indicating that dynamic port allocation is active.

4. The method of claim 2, wherein the step of transmitting said upcode includes the step of transmitting a simulated RTS or DTR code.

5. The method of claim 2, wherein said step of transmitting a synchronization code includes the step of transmitting a sequence of zeros followed by two ones.

6. In a multi-port modem, a method of allocating bandwidth to a recipient port which is currently idle from a donor port which is to have its bandwidth decreased without interruption of other ports of said modem, said multi-port modem being of the kind that transmits and receives data to and from a plurality of ports including said donor and recipient ports using time division multiplexing so that each port uses one or more time slots for data transmission, and wherein the data are transmitted over a transmission medium, the method comprising the steps of:

receiving a request for bandwidth from an external source recipient port;

coordinating a change in bandwidth allocation by transmitting a handshaking protocol over said donor port time slot and said recipient port time slot to signify that the port is to relinquish bandwidth to said port requesting bandwidth; and

reconfiguring said multi-port modem to allocate the bandwidth to said recipient port from said donor port without interruption of said other ports.

7. The method of claim 6, wherein said coordinating step further comprises the steps of:

transmitting a drop code over said donor port'"'"'s allocated bandwidth to signal that said donor port is donating its bandwidth;

transmitting a multiplexer configuration code over said donor port to specify a new multiplexer configuration;

transmitting a synchronization code to synchronize a reconfiguration of said other ports if necessary; and

transmitting an upcode to signal a start of transmission using said new multiplexer configuration over said donor port and said recipient port.

8. The method of claim 7, wherein the step of transmitting said drop code includes the step of transmitting a simulated RTS or DTR code followed by transmitting a code indicating that dynamic port allocation is active.

9. The method of claim 7, wherein the step of transmitting said upcode includes the step of transmitting a simulated RTS or DTR code.

10. The method of claim 7, wherein said step of transmitting a synchronization code includes the step of transmitting a sequence of zeros followed by two ones.

11. In a multi-port modem, a method of allocating bandwidth from a donor port which is to reduce its bandwidth to a recipient port which is to have its bandwidth allocation increased without interrupting other ports in said modem, said multi-port modem being of the kind that transmits and receives data to and from a plurality of ports including said donor and recipients ports over a transmission medium using time division multiplexing so that each port uses one or more time slots for data transmission, and wherein the data are transmitted over said transmission medium, the method comprising the steps of:

transmitting a code over said donor port time slot to signify that said donor port is going idle;

coordinating a change in transmission rate of said recipient port by transmitting a handshaking protocol over the time slots of said idle donor port and said recipient port; and

reconfiguring said multi-port modem to allocate the bandwidth of said donor port to said recipient port without interruption of said other ports.

12. The method of claim 11, wherein said coordinating step further comprises the steps of:

transmitting a drop code over said donor port to signal that said donor port is donating its time slot;

transmitting a multiplexer configuration code over said donor port to specify a new multiplexer configuration;

transmitting a synchronization code over said donor port to synchronize reconfiguration of said other ports if required; and

transmitting an upcode to signal a start of transmission using said new multiplexer configuration over said recipient port at an increased data rate.

13. The method of claim 12, wherein the step of transmitting said drop code includes the step of transmitting a simulated RTS or DTR code followed by transmitting a code indicating that dynamic port allocation is active.

14. The method of claim 12, wherein the step of transmitting said upcode includes the step of transmitting a simulated RTS or DTR code.

15. The method of claim 12, wherein said step of transmitting a synchronization code includes the steps of transmitting a sequence of zeros followed by two ones.

16. In a multi-port modem, a method of allocating bandwidth to a recipient port from a donor port which is to have its bandwidth decreased without interruption of other ports of said modem, said multi-port modem being of the kind that transmits and receives data to and from a plurality of ports including said donor and recipient ports using time division multiplexing so that each port uses one or more time slots for data transmission, and wherein the data are transmitted over a transmission medium, the method comprising the steps of:

receiving a request for bandwidth to be allocated to a recipient port;

coordinating a change in bandwidth allocation by transmitting a handshaking protocol over said donor port time slot and said recipient port time slot to signify that the port is to relinquish bandwidth to said recipient port; and

reconfiguring said multi-port modem to allocate the bandwidth to said recipient port from said donor port without interruption of said other ports.

17. The method of claim 16, wherein said coordinating step further comprises the steps of:

transmitting a drop code over said donor port'"'"'s to signal that said donor port is donating its time slot allocated bandwidth;

transmitting a multiplexer configuration code over said donor port to specify a new multiplexer configuration;

transmitting a synchronization code to synchronize a reconfiguration of said other ports if necessary; and

transmitting an upcode to signal a start of transmission using said new multiplexer configuration over said donor port and said recipient port.

18. The method of claim 17, wherein the step of transmitting said drop code includes the step of transmitting a simulated RTS or DTR code followed by transmitting a code indicating that dynamic port allocation is active.

19. The method of claim 17, wherein the step of transmitting said upcode includes the step of transmitting a simulated RTS or DTR code.

20. The method of claim 17, wherein said step of transmitting a synchronization code includes the step of transmitting a sequence of zeros followed by two ones.