Link fault handling in fronthaul communication networks

Patent metadata

Field	Value
Publication number	US-11206557-B2
Application number	US-201916543344-A
Country	US
Kind code	B2
Filing date	Aug 16, 2019
Priority date	Aug 16, 2019
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

In a fronthaul network system, when a CPRI link fault is detected at either of the REC or RE, both the REC and RE perform a Layer 1 synchronization. The fault may be a loss of signal, loss of frame, or a line code violation, which also translates to a loss of signal if seen beyond a threshold. A proxy slave recognizes the fault in a CPRI signal from a first radio device and inserts the fault alarm into a header of a radio over Ethernet frame. The proxy slave continues to communicate the signal for a configured number of hyper-frames. A proxy master receives the signal and communicates the signal and the fault alarm to a receiving radio device for a configured number of hyper-frames. The proxy and radio devices all perform a joint resynchronization.

First claim

What is claimed is:

1. A method, comprising:
by a processor of a proxy slave node computing device in a fronthaul system,
receiving a wireless signal from a radio device;
mapping the wireless signal to a data frame;
based on the mapping, recognizing a link fault in the wireless signal;
based on recognizing the link fault, logging a fault alarm into a field of the data frame;
communicating the data frame with the logged fault alarm a configured number of times to a receiving proxy master node; and

at a time after the communicating of the data frame the configured number times, initiating a resynchronization of the proxy slave node in conjunction with other nodes of the fronthaul system;
by a processor of the receiving proxy master node in the fronthaul system,
receiving the data frame from the proxy slave node;
reading the fault alarm in the field of the data frame;
mapping the data frame to a second wireless signal;
communicating the second wireless signal to a second radio device; and
based on reading the fault alarm, initiating a resynchronization in conjunction with other nodes of the fronthaul system.

2. The method of claim 1 , wherein the link fault is a loss of signal.

3. The method of claim 1 , wherein the link fault is a loss of frame error.

4. The method of claim 1 , wherein the field of the data frame with the logged link fault is in an optional field of a radio over Ethernet header.

5. The method of claim 1 , wherein the link fault is a line code violation.

6. The method of claim 5 , wherein the field of the data frame with the logged link fault is a field within a variable-sized extension header in a radio over Ethernet header.

7. The method of claim 5 , wherein the field of the data frame with the logged link fault is a field within a fixed-sized extension header in a radio over Ethernet header.

8. The method of claim 1 , wherein the wireless signal is received via a common public radio interface with a line rate based on 8 b /10 b encoding.

9. The method of claim 8 , further comprising propagating, by the receiving proxy master node, an 8-bit block to a receiving radio device.

10. The method of claim 1 , wherein the link fault is a synchronization header violation and the wireless signal is received via a common public radio interface with a line rate based on 64b/66b encoding.

11. The method of claim 10 , wherein the receiving proxy master node propagates a 64-bit block of data to a receiving radio device.

12. The method of claim 1 , wherein the field of the data frame with the logged link fault is a field in an experimental radio over Ethernet subType header.

13. The method of claim 1 , wherein the data frame is a hyperframe and the configured number of times is ten.

14. The method of claim 1 , wherein the data frame is a radio over Ethernet frame.

15. A computer program product, comprising:
a first non-transitory computer-readable medium having computer-readable program instructions embodied thereon that, when executed by a first processor of a proxy slave node in a fronthaul system, cause the first processor to:
receive a wireless signal from a radio device;
map the wireless signal to a data frame;
based on the mapping, recognize a link fault in the wireless signal;
based on recognizing the link fault, log a fault alarm into a field of the data frame;
communicate the data frame with the logged fault alarm a configured number of times to a receiving proxy master node; and
initiate a resynchronization of the proxy slave node in conjunction with other nodes of the fronthaul system; and

a second non-transitory computer-readable medium having computer-readable program instructions embodied thereon that, when executed by a second processor of the receiving proxy master node in the fronthaul system, cause the second processor to:
receive the data frame from the proxy slave node;
read the fault alarm in the field of the data frame;
map the data frame to a second wireless signal;
communicate the second wireless signal to a second radio device; and
based on reading the fault alarm, initiate a resynchronization in conjunction with other nodes of the fronthaul system.

16. The computer program product of claim 15 , wherein the link fault is a loss of signal.

17. The computer program product of claim 15 , wherein the link fault is a loss of frame error.

18. A system, comprising:
a first storage device; and
a first processor communicatively coupled to the first storage device, wherein the first processor executes application code instructions that are stored in the first storage device to cause the system to:
receive a wireless signal from a radio device;
map the wireless signal to a data frame;
based on the mapping, recognize a link fault in the wireless signal;
based on recognizing the link fault, log a fault alarm into a field of the data frame;
communicate the data frame with the logged fault alarm a configured number of times to a receiving proxy master node; and
initiate a resynchronization of the proxy slave node in conjunction with other nodes of the fronthaul system;

a second storage device; and
a second processor communicatively coupled to the second storage device, wherein the second processor executes application code instructions that are stored in the second storage device to cause the system to:
receive the data frame communicated by the first processor;
read the fault alarm in the field of the data frame;
map the data frame to a second wireless signal;
communicate the second wireless signal to a second radio device; and
based on reading the fault alarm, initiate a resynchronization in conjunction with other nodes of the fronthaul system.

19. The system of claim 18 , wherein the link fault is a line code violation.

Assignees

• Cisco Tech Inc

Inventors

• Anand Prashant
• Kumar Manoj
• Kayamkulangara Sudhir
• Boopalan Manigandan
• K Dinuraj

Classifications

• H04L41/069 Primary

  using logs of notifications; Post-processing of notifications · CPC title

• H04L41/0677

  Localisation of faults · CPC title

• H04L41/0654

  using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) · CPC title

• H04W24/04 Primary

  Arrangements for maintaining operational condition · CPC title

• H04W84/20

  Leader-follower arrangements · CPC title