Method and system for shortening the length of time gaps between data units in a data switching network

• US 8,218,575 B2
• Filed: 11/24/2008
• Issued: 07/10/2012
• Est. Priority Date: 11/26/2007
• Status: Active Grant

• Current Assignee: Jang Partners LLC (Intellectual Ventures LLC)
• Original Assignee: Versitech Limited (Government of Hong Kong Special Administrative Region)
• Inventors: Li, Chun-Yin, Wai, Alexander Ping-Kong, Li, Victor On-Kwok
• Primary Examiner(s): Wu, Jianye
• Application Number:
  US12/277,028
• Publication Number:
  US 20090135853A1
• Time in Patent Office: 1,324 Days
• Field of Search: None
• US Class Current: 370/474
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/002 using optical delay lines or optical buffers or optical recirculation
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0045 Synchronisation

Abstract

A method for shortening the length of time gaps between data units in a data switching network; the method comprising: arranging a group of K data units received consecutively at an input of a first device in K time units, where K is a positive integer; sending the arranged K data units to the inputs of M devices, where M is a positive integer; transferring a group of H_j data units of the arranged K data units by a device j of the M devices from its inputs to its outputs within a time unit T_x in the K unit time period, where H_j is a positive integer and the sum of H_j for j=1, . . . M is equal to K, where H_jK; arranging the data units sent to the devices of the M devices transferring at time unit T_x such that no two inputs of the devices of the M devices transferring at time unit T_x receive the same data unit at any moment; and repeatedly combining and arranging the K data units from the outputs of the M devices by a second device such that the K data units appear at the output of the second device consecutively.

Claims

1. A method for shortening the length of time gaps between data units in a data switching network;

the method comprising;

arranging a group of K data units received consecutively at an input of a first device in a time period of K units, where K is a positive integer, and where a timer period of one unit is a period of time necessary for receiving one data unit at the input of the first device;

sending the arranged K data units to the inputs of M devices, where M is a positive integer;

transferring a group of H_j data units of the arranged K data units by a device j of the M devices from its inputs to its outputs within a time unit T_x where the time period T_x is less than or equal to one unit and, where H_j is a positive integer and the sum of H_j for j=1, . . . M is equal to K, where H_jK;

arranging the data units sent to the devices of the M devices transferring during the time period T_x such that no two inputs of the devices of the M devices transferring during the time period T_x receive the same data unit at any moment; and

repeatedly combining and arranging the K data units from the outputs of the M devices by a second device such that the K data units appear at the output of the second device consecutively.

2. The method according to claim 1, wherein the data switching network is a slotted network.

3. The method according to claim 2, wherein each data unit is a sequence of data bits whose total transmission time is smaller than a unit of time.

4. The method according to claim 3, wherein the data unit does not contain any information of the path to the destination of the data unit.

5. The method according to claim 3, wherein the data unit contains dummy bits that do not carry information, and a period of time without signal transmission is considered as a sequence of dummy bits.

6. The method according to claim 1, wherein the data switching network is a packet switching network.

7. The method according to claim 6, wherein each data unit is a packet which contains header and payload, the header having information indicating the path to the destination of the packet.

8. The method according to claim 1, wherein the data switching network is an optical network.

9. The method according to claim 1, wherein the first device is an optical splitter or an optical switch, with K outputs connecting to the inputs of the M devices such that K data units are sent to the M devices for each K unit time period.

10. The method according to claim 1, further comprising adding an optical delay element before the first device such that the K data units are delayed before entering the first device.

11. The method according to claim 1, further comprising adding an optical delay element after the outputs of the first device and before the inputs of the M devices such that the K data units are delayed before entering the M devices.

12. The method according to claim 11, wherein the optical delay elements at the inputs of the devices of the M devices are transferring data units within the same predefined time unit T_x have different delay values such that no two inputs of the devices receive the same data unit at any time.

13. The method according to claim 1, wherein the second device is an optical combiner or an optical switch with K inputs connecting to the outputs of the M devices such that the K data units are combined and sent via the output of the second device consecutively.

14. The method according to claim 13, further comprising adding optical delay elements at the outputs of the M devices such that the K data units are delayed before entering the inputs of the second device.

15. The method according to claim 14, wherein the delay elements at the outputs of the M devices have different delay values such that the K data units from the outputs of the M devices appear consecutively at the output of the second device.

16. The method according to claim 1, further comprising connecting a pilot message channel to a third device to describe the K data units sent to the inputs of the M devices such that the M devices are configured by the third device before the arrival of the K packets.

17. The method according to claim 10, wherein the optical delay elements are variable and fixed delay value optical fiber delay lines.

18. The method according to claim 1, wherein the device j is an optical switch with reconfiguration time not larger than K−

1 time units.

19. The method according to claim 1, wherein K is greater than one.

21. The method according to claim 1, wherein the K time units required for the first device to receive the K data units comprise a time period of length L, where L is a positive real number.

22. The method according to claim 1, wherein the K unit time period comprise a time period of length L, where L is a positive real number.

20. A system for shortening the length of time gaps between data units in a data switching network;

the system comprising;

a first device having an input receiving an arranged group of K data units consecutively in a time period of K units, where K is a positive integer, and where a time period of one unit is a period of time necessary for receiving one data unit;

M devices having inputs to receive the arranged K data units, where M is a positive integer;

a device j of the M devices to transfer a group of H_j data units of the arranged K data units from its inputs to its outputs within a time unit T_x, where time period T_x is less than or equal to one unit, where H_j is a positive integer and the sun of H_j for j=1, . . . M is equal to K, where H_j≦

K;

wherein the data units sent to the devices of the M devices transferring during the time period T_x are arranged such that no two inputs of the devices of the M devices transferring during the time unit T_x receive the same data unit at any moment; and

repeatedly combining and arranging the K data units from the outputs of the M devices by a second device such that the K data units appear at the output of the second device consecutively.

23. A method for shortening the length of time gaps between data units in a data switching network, the method comprising:

arranging a group of K data units received consecutively at an input of a first device in a time period of length L, where K is a positive integer and L is a positive real number;

sending the arranged K data units to the inputs of M devices, where M is a positive integer;

transferring a group of H_j data units of the arranged K data units by a device j of the M devices from its inputs to its outputs within a time period T_j of length L_j, where H_j is a positive integer and the sum of H_j for j=1, . . . M is equal to K, where H_jK, and L_j is a positive real number, where L_jL for j=1, . . . M;

arranging the data units sent to the devices of the M devices transferring during the time period T_j such that no two inputs of the devices of the M devices transferring during the time period T_j receive the same data unit at any moment for j=1, . . . M; and

repeatedly combining and arranging the K data units from the outputs of the M devices by a second device such that the K data units appear at the output of the second device consecutively.