Techniques for bus interval timing management in a USB extension system

A downstream USB extension device configured to perform actions comprising:

• transmitting, by the downstream USB extension device via a USB downstream facing port, a first outgoing bus interval message in response to receiving a first incoming bus interval message from an upstream USB extension device via an extension medium at a first time;
• determining, by the downstream USB extension device, an expected time of receipt of a second incoming bus interval message based on the first time;
• in response to determining that the second incoming bus interval message has been received at a reception time that is before the expected time of receipt, transmitting, by the downstream USB extension device via the USB downstream facing port, a second outgoing bus interval message at a second time based on a difference between the reception time and the expected time of receipt;
• and
• in response to determining that the second incoming bus interval message has not been received before the expected time of receipt, transmitting, by the downstream USB extension device via the USB downstream facing port, the second outgoing bus interval message at the expected time of receipt.

A system, comprising:

• an extension medium;
• and
• a downstream USB extension device communicatively coupled to the extension medium and configured to perform actions comprising:
• transmitting, by the downstream USB extension device via a USB downstream facing port, a first outgoing bus interval message in response to receiving a first incoming bus interval message from an upstream USB extension device via the extension medium at a first time;
• determining, by the downstream USB extension device, an expected time of receipt of a second incoming bus interval message based on the first time;
• in response to determining that the second incoming bus interval message has been received at a reception time that is before the expected time of receipt, transmitting, by the downstream USB extension device via the USB downstream facing port, a second outgoing bus interval message at a second time based on a difference between the reception time and the expected time of receipt;
• and
• in response to determining that the second incoming bus interval message has not been received before the expected time of receipt, transmitting, by the downstream USB extension device via the USB downstream facing port, the second outgoing bus interval message at the expected time of receipt.