USB extender

• US 20050278472A1
• Filed: 06/14/2004
• Published: 12/15/2005
• Est. Priority Date: 06/14/2004
• Status: Abandoned Application

• Current Assignee: Video Products Incorporated
• Original Assignee: Video Products Incorporated
• Inventors: Gierke, Justin Thomas
• Application Number:
  US10/867,083
• Publication Number:
  US 20050278472A1
• Time in Patent Office: Days
• US Class Current: 710/313
• CPC Class Codes: G06F 13/4045 where the bus bridge performs an extender function

Abstract

The present invention relates to a system and method for extending the distance between USB hosts and USB devices. Provided are USB 2.x compatible extenders capable of separating a USB device from a USB host by more than 30 meters while maintaining an at least approximately 480 Mb/sec data rate.

Claims

1. A USB extender connectable to a USB host and to a USB device for extending the distance between the USB host and the USB device, the USB extender having the capacity to extend a D+ signal and a D−

signal between a USB host and at least one USB device more than 30 meters wherein the data transfer rate of the D+ and D−

signals between the USB host and USB device is at least approximately 480 Mb/sec and wherein the D+ signal and D−

signal are skewed by less than 100 ps.

2. The USB extender of claim 1 wherein the USB extender is connectable to a non-USB communications channel and wherein the D+ and D−

signals are transmitted over the non-USB communications channel.

3. The USB extender of claim 2 wherein the non-USB communications channel comprises at least one of:

copper wire, optical fiber, and wireless.

4. The USB extender of claim 3 wherein the D+ signal is transmitted over one wire of a copper wire pair and the D−

signal is transmitted over the other wire of the copper wire pair.

5. The USB extender of claim 3 wherein the D+ signal and D−

signals are transmitted on separate optical fiber cables.

6. The USB extender of claim 3 wherein the D+ and D−

signal are combined into a single-ended at least approximately 960 Mb/sec signal.

7. The USB extender of claim 6 wherein the single-ended at least approximately 960 Mb/sec signal is transmitted over a single optical fiber cable.

8. The USB extender of claim 1 wherein the USB extender is connectable to a USB host and to at least one USB device via USB communications channels.

9. The USB extender of claim 1 wherein the USB extender is configured to accept any USB device.

10. The USB extender of claim 1 wherein the USB extender is connectable to multiple USB devices.

11. The USB extender of claim 1 wherein the USB extender extends the distance between a USB host and a USB device without emulating either the USB host or the USB device.

12. The USB extender of claim 1 wherein the USB extender is a passive extender.

13. A USB extender assembly, comprising:

the USB extender of claim 1;

a non-USB communications channel;

at least one USB device; and

a USB host.

14. The USB extender of claim 13 wherein the USB extender comprises:

a host unit connectable to the USB host and the non-USB communications channel; and

a device unit connectable to the USB device and the non-USB communications channel.

15. The USB extender of claim 14 wherein the device unit further comprises a hub connectable to multiple USB devices.

16. The USB extender of claim 14 wherein the host unit and device each comprise:

a transmitter module having a transmitter for receiving USB data from the USB host or the USB device and transmitting the received USB data over a non-USB communications channel; and

a receiver module having a receiver for receiving data from the non-USB communications channel and transmitting the received USB data to the USB host or the USB device.

17. The USB extender of claim 16 wherein both the transmitter and receiver modules are communicably coupled and function in a master-slave relationship.

18. The USB extender of claim 17 wherein the receiver module is the master and the transmitter module is the slave.

19. The USB extender of claim 16 wherein the transmitter comprises at least one of a copper wire transmitter, a wireless transmitter, and a optical transmitter.

20. The USB extender of claim 16 wherein the transmitter module comprises:

a synchronizer for synchronizing the D+ and D−

signals and decrease skew introduced between the extender and the USB host or USB device; and

a transmitter for each of the D+ and D−

for transmitting the D+ and D−

signals over the non-USB communications channel.

21. The USB extender of claim 16 wherein the receiver module comprises:

a receiver for each of the D+ and D−

signals for receiving the D+ and D−

signals transmitted over the non-USB communications channel; and

a synchronizer for synchronizing the D+ and D−

signals and decrease skew introduced between the host unit and the device unit.

22. The USB extender of claim 16 wherein the transmitter module comprises a differential to single-ended converter, wherein the USB data received by the transmitter is first converted by the differential to single-ended converter and wherein the transmitter is a single-ended transmitter.

23. The USB extender of claim 16 wherein the receiver module comprises:

a single-ended receiver for receiving converted single-ended USB data from the non-USB communications channel and a single-ended to differential converter.

24. A method for extending the distance between a USB host and at least one USB device, the method comprising:

receiving at a device unit a D+ signal and a D−

signal from at least one USB device via a USB communications channel, the D+ and D−

signals being at least approximately 480 Mb/sec signals;

converting the D+ and D−

signals to a single-ended at least approximately 960 Mb/sec signal;

transmitting the at least approximately 960 Mb/sec single-ended signal over a non-USB communications channel;

receiving at a host unit the at least approximately 960 Mb/sec single-ended signal via the non-USB communications channel;

converting the at least approximately 960 Mb/sec single-ended signal to at least approximately 480 Mb/sec D+ and D−

signals; and

sending the at least approximately 480 Mb/sec D+ and D−

signals to a USB host via a USB communications channel;

whereby the USB host and the at least one USB device are separated by more than 30 meters.

25. The method of claim 24 further comprising:

receiving at a host unit a D+ signal and a D−

signal from a USB host via a USB communications channel, the D+ and D−

signals being at least approximately 480 Mb/sec signals;

converting the D+ and D−

signals to a single-ended at least approximately 960 Mb/sec signal;

transmitting the at least approximately 960 Mb/sec single-ended signal over a non-USB communications channel;

receiving at a device unit the at least approximately 960 Mb/sec single-ended signal via the non-USB communications channel;

converting the at least approximately 960 Mb/sec single-ended signal to at least approximately 480 Mb/sec D+ and D−

signals; and

sending the at least approximately 480 Mb/sec D+ and D−

signals to at least one USB device via a USB communications channel.

26. A method for extending the distance between a USB host and at least one USB device, the method comprising:

receiving at a device unit a D+ signal and a D−

signal from at least one USB device via a USB communications channel, the D+ and D−

signals being at least approximately 480 Mb/sec signals;

transmitting the at least approximately 480 Mb/sec D+ and D−

signals over a non-USB communications channel;

receiving at a host unit the at least approximately 480 Mb/sec D+ and D−

signals via the non-USB communications channel;

reducing skew between D+ and D−

signals resulting from transmission over the non-USB communications channel; and

sending the at least approximately 480 Mb/sec D+ and D−

signals to a USB host via a USB communications channel;

whereby the USB host and the at least one USB device are separated by more than 30 meters.

27. The method of claim 26 further comprising:

receiving at a host unit a D+ signal and a D−

signal from a USB host via a USB communications channel, the D+ and D−

signals being at least approximately 480 Mb/sec signals;

transmitting the at least approximately 480 Mb/sec D+ and D−

signals over a non-USB communications channel;

receiving at a device unit the at least approximately 480 Mb/sec D+ and D−

signals via the non-USB communications channel;

reducing skew between D+ and D−

signals resulting from transmission over the non-USB communications channel; and

sending the at least approximately 480 Mb/sec D+ and D−

signals to at least one USB device via a USB communications channel.