END-TO-END DELAY MANAGEMENT FOR DISTRIBUTED COMMUNICATIONS NETWORKS

• US 20120327789A1
• Filed: 06/21/2011
• Published: 12/27/2012
• Est. Priority Date: 06/21/2011
• Status: Active Grant

• Current Assignee: Commscope Emea Limited (CommScope Holding Company, Inc.), CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Hedin, John M., Grenier, James Robert
• Granted Patent: US 8,743,718 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route

Abstract

A method for calculating delay in a distributed antenna system includes sending a ping initiation message from a remote node to a host node in a distributed antenna system. The ping initiation message uniquely identifies a first communication port of the remote node to the host node with a unique identification. The method also includes receiving a ping reply message at the remote node. The ping reply message corresponds to the ping initiation message and also uniquely identifies the first communication port of the remote node with the unique identification. The method also includes determining, at the remote node, whether the ping reply message corresponds to the first communication port of the remote node based on the unique identification. The method also includes, when the ping reply message corresponds to the first communication port of the remote node, calculating the round-trip time delay between sending the ping initiation message and receiving the ping reply message at the remote node.

Claims

1. A distributed antenna system comprising:

a host node including a host node processor, the host node having a first communication port communicatively coupled to a base station of a mobile telephone network, the host node also having a second communication port;

a remote node in communication with the host node, the remote node including a remote node processor, a third communication port communicatively coupled to the second communication port of the host node, and a fourth communication port communicatively coupled to an antenna;

wherein the remote node processor comprises program instructions that;

cause the remote node to send a ping initiation message to the host node across a communication link established between the third communication port and the second communication port, wherein the ping initiation message includes a unique identification that uniquely identifies at least one of the third communication port and the fourth communication port to the host node;

cause the remote node to determine whether a ping reply message received from the host node corresponds to the at least one of the third communication port and the forth communication port based on the unique identification; and

when the ping reply message received from the host node corresponds to the at least one of the third communication port and the forth communication port, cause the remote node to calculate the elapsed time between sending the ping initiation message and receiving the ping reply message; and

wherein the host node processor comprises program instructions that;

cause the host node to validate the ping initiation message received from the remote node; and

when the ping initiation message is validated, cause the host node to send the ping reply message to the remote node, wherein the ping reply message corresponds to the ping initiation message and also uniquely identifies the at least one of the third communication port and the fourth communication port of the remote node.

2. The distributed antenna system of claim 1, wherein the unique identification is a path code that identifies the path between the at least one of the third communication port and the fourth communication port of the remote node and at least one of the first communication port and the second communication port of the host node.

3. The distributed antenna system of claim 2, wherein the path code uniquely identifies the host node, the at least one of the first communication port and the second communication port, the at least one of the third communication port and the fourth communication port, and the communication link path between the host node and the remote node.

4. The distributed antenna system of claim 1, wherein the remote node is separated from the host node by at least one additional remote node.

5. The distributed antenna system of claim 1, wherein at least one of the first communication port and the fourth communication port is part of a radio frequency to digital interface that converts between radio frequency signals and digital signals.

6. The distributed antenna system of claim 1, wherein a single bit in each timeslot of a data frame is used to transmit the ping initiation message and the ping reply message.

7. A method for calculating delay in a distributed antenna system comprising:

sending a ping initiation message from a remote node in the distributed antenna system to a host node in the distributed antenna system, wherein the ping initiation message uniquely identifies a first communication port of the remote node to the host node with a unique identification;

receiving a ping reply message at the remote node;

determining, at the remote node, whether the ping reply message uniquely identifies the first communication port of the remote node with the unique identification; and

when the ping reply message uniquely identifies the first communication port of the remote node, calculating the round-trip time delay between sending the ping initiation message and receiving the ping reply message at the remote node.

8. The method of claim 7, wherein the unique identification is a path code that identifies the path between the first communication port of the remote node and a second communication port of the host node.

9. The method of claim 8, wherein the path code uniquely identifies the host node, the first communication port, the second communication port, and the communication link path between the host node and the remote node.

10. The method of claim 7, further comprising:

calculating a signal path delay at the remote node based on the round-trip delay.

11. The method of claim 10, wherein calculating the signal path delay includes:

dividing the round-trip delay by a number to determine the one-way delay between at least one of sending and receiving the ping initiation message and sending and receiving the ping reply message.

12. The method of claim 10, wherein calculating the signal path delay includes:

factoring intrinsic processing delays into the calculation of signal path delay.

13. The method of claim 12, wherein the intrinsic processing delays are pre-determined processing delays associated with internal processing occurring at at least one of the host node and the remote node.

14. The method of claim 10, wherein the signal path delay approximates at least one of:

a forward path time delay between radio frequency spectrum being received at a radio frequency port of the host node and being output at a radio frequency port of the remote node; and

a reverse path time delay between radio frequency spectrum being received at the radio frequency port of the remote node and being output at the radio frequency port of the host node.

15. The method of claim 7, further comprising forwarding the ping initiation message received from the remote node toward the host node at a second remote node positioned between the remote node and the host node;

and

forwarding the ping reply message received from the host node toward the remote node at the second remote node positioned between the remote node and the host node.

16. The method of claim 8, wherein validating the ping initiation message includes performing a cyclic redundancy check on the ping initiation message.

17. The method of claim 7, further comprising:

determining, at the remote node, whether the ping reply message is received before a predefined timeout period elapses since the ping initiation message was sent before determining whether the ping reply message uniquely identifies the first communication port of the remote node with the unique identification; and

wherein determining whether the ping reply message uniquely identifies the first communication port of the remote node with the unique identification only occurs when the ping reply message is received before the predefined timeout period elapses since the ping initiation message was sent;

when the ping message is not received before the predefined timeout period elapses, determining whether a predefined number of unsuccessful attempts at sending the ping initiation message has been reached;

when the predefined number of unsuccessful attempts at sending the ping initiation message has been reached, resending the ping initiation message when a next ping trigger occurs.

18. The method of claim 17, wherein the next ping trigger occurs at a pseudo-random time determined using a pseudo-random back-off algorithm to minimize the chance of a collision between other upstream messages.

19. The method of claim 7, further comprising:

determining, at the remote node, whether the ping reply message has been successfully received a predefined number of times; and

wherein calculating the round-trip time delay between sending the ping initiation message and receiving the ping reply message at the remote unit only occurs when the ping reply message has been successfully received a predefined number of times; and

when the ping reply message has not been successfully received a predefined number of times, resending the ping initiation message when a next ping trigger occurs.

20. The method of claim 19, wherein the next ping trigger occurs at a pseudo-random time determined using a pseudo-random back-off algorithm to minimize the chance of a collision between other upstream messages.

21. The method of claim 7, further comprising:

when the ping reply message received at the remote node does not correspond to at least one communication port of the remote node, ignoring the ping reply message at the remote node.

22. The method of claim 7, further comprising:

determining, at the remote node, whether a predefined number of unsuccessful attempts at sending the ping initiation message has been reached; and

when the predefined number of unsuccessful attempts at sending the ping initiation message has been reached, reporting a path integrity alarm.

23. The method of claim 7, further comprising:

converting messages received from an antenna connected to the first communication port from first radio frequency signals to first digital signal; and

converting messages to be transmitted via the antenna from second digital signals to second radio frequency signals.

24. The method of claim 7, further comprising:

receiving the ping initiation message at the host node;

validating the ping initiation message at the host node; and

when the ping initiation message is validated, sending the ping reply message to the remote node.

25. The method of claim 24, further comprising:

when a third message received at the host node is not validated at the host node, ignoring the third message.

26. The method of claim 24, further comprising:

converting messages received from an antenna connected to a second communication port of the host node from first radio frequency signals to first digital signal; and

converting messages to be transmitted via the antenna from second digital signals to second radio frequency signals.

27. The method of claim 7, wherein a single bit in each timeslot of a data frame is used to transmit the ping initiation message and the ping reply message.

28. The method of claim 7, further comprising:

after calculating the round-trip time delay between sending the ping initiation message and receiving the ping reply message at the remote node, resetting an attempts count and a message received count, wherein the attempts count tracks how many unsuccessful attempts have been made at pinging the host node, wherein the message received count tracks how many times the message has been successfully received.

29. The method of claim 7, further comprising:

waiting for a next ping trigger;

once the next ping trigger has occurred, sending a second ping initiation message from the remote node to the host node, wherein the second ping initiation message uniquely identifies a second communication port of the remote node to the host node with a second unique identification;

receiving a second ping reply message at the remote node;

determining, at the remote node, whether the second ping reply message uniquely identifies the second communication port of the remote node with the second unique identification; and

when the second ping reply message uniquely identifies the second communication port of the remote node, calculating the round-trip time delay between sending the second ping initiation message and receiving the second ping reply message at the remote node.

30. A remote node in a distributed antenna system comprising:

a first communication port communicatively coupled to an antenna;

a second communication port communicatively coupled to a host node; and

a remote node processor, wherein the remote node processor comprises program instructions that;

cause the remote node to send a ping initiation message to the host node across a communication link established between the second communication port and the host node, wherein the ping initiation message includes a unique identification that uniquely identifies at least one of the first communication port and the second communication port to the host node;

cause the remote node to determine whether a ping reply message received from the host node corresponds to the at least one of the first communication port and the second communication port based on the unique identification; and

when the ping reply message received from the host node corresponds to the at least one of the first communication port and the second communication port, cause the remote node to calculate the elapsed time between sending the ping initiation message and receiving the ping reply message.

31. The remote node of claim 30, wherein the unique identification is a path code that identifies the path between the at least one of the first communication port and the second communication port of the remote node and at least one communication port of the host node.

32. The remote node of claim 31, wherein the path code uniquely identifies the host node, the at least one communication port of the host node, the at least one of the first communication port and the second communication port of the remote node, and the communication link path between the host node and the remote node.

33. The remote node of claim 30, wherein the remote node is separated from the host node by at least one additional remote node in the distributed antenna system.

34. The remote node of claim 30, wherein the first communication port is part of a radio frequency to digital interface that converts between radio frequency signals and digital signals.

35. The remote node of claim 30, wherein a single bit in each timeslot of a data frame is used to transmit the ping initiation message and the ping reply message.

36. A program product comprising program instructions, embodied on a storage medium, the program instructions cause at least one programmable processor in a remote node within a distributed antenna system to:

cause the remote node to send a ping initiation message to a host node across a communication link established between the remote node and the host node, wherein the ping initiation message includes a unique identification that uniquely identifies at least one communication port of the remote node to the host node;

cause the remote node to determine whether a ping reply message received from the host node corresponds to the at least one communication port based on the unique identification; and

when the ping reply message received from the host node corresponds to the at least one communication port, calculate the elapsed time between sending the ping initiation message and receiving the ping reply message.