Link establishment between a radio equipment controller (REC) and radio equipment (RE) in a fronthaul network

Patent metadata

Field	Value
Publication number	US-11601899-B2
Application number	US-202217881043-A
Country	US
Kind code	B2
Filing date	Aug 4, 2022
Priority date	Feb 1, 2019
Publication date	Mar 7, 2023
Grant date	Mar 7, 2023

Abstract

Techniques that provide link establishment between a radio equipment controller (REC) and a radio equipment (RE) in a fronthaul network are described herein. In one embodiment, a method includes performing, Common Public Radio Interface (CPRI) Layer 1 (L1) link auto-negotiation operations to establish a CPRI link between the REC and RE. A proxy slave may achieve a hyper frame number (HFN) synchronization with the REC at a link bit rate for a first CPRI bit stream and communicate the first CPRI bit stream and the link bit rate to a proxy master. The proxy master may communicate a second CPRI bit stream to the proxy slave to transmit to the REC. The L1 link auto-negotiation operations are completed and CPRI link is established between the REC and the RE when the REC achieves a HFN synchronization for the second CPRI bit stream.

First claim

What is claimed is:

1. In a fronthaul network comprising a radio equipment controller connected to a proxy slave, a proxy master connected to a radio equipment, and an Ethernet network connecting the proxy master and the proxy slave, a method for establishing a Common Public Radio Interface (CPRI) link between the radio equipment controller and the radio equipment over the Ethernet network, the method comprising:
receiving, at the proxy slave from the radio equipment controller, a first CPRI bit stream transmitted at a first plurality of link bit rates at respective transmit time intervals;
attempting to decode, at the proxy slave, the first CPRI bit stream at a second plurality of link bit rates at respective reception time intervals;
on achieving hyper frame number synchronization (HFNSync) at a first link bit rate of the second plurality of link bit rates, mapping the first CPRI bit stream to one or more Radio over Ethernet (RoE) frames, wherein at least one of the one or more RoE frames comprises a header indicating the first link bit rate;
transmitting the one or more RoE frames to the proxy master;
on receiving one or more RoE frames from the proxy master, wherein the one or more RoE frames received from the proxy master comprise a second CPRI bit stream transmitted by the radio equipment:
de-mapping the one or more RoE frames received from the proxy master; and
transmitting the second CPRI bit stream to the radio equipment controller at the first link bit rate; and

upon HFNSync being achieved between the proxy slave and the radio equipment controller using the first link bit rate, establishing the CPRI link using the first link bit rate.

2. The method of claim 1 , wherein the CPRI link is within one transmit time interval of the radio equipment controller.

3. The method of claim 1 , wherein the method is repeated until the radio equipment controller achieves the hyper frame number synchronization for the second CPRI bit stream transmitted by the proxy slave at the first link bit rate.

4. The method of claim 1 , wherein the first and second plurality of link bit rates are synchronized to have a common subset of link bit rates.

5. The method of claim 1 , further comprising transmitting Radio over Ethernet (RoE) frames between the proxy master and the proxy slave using the established CPRI link.

6. The method of claim 1 , further comprising: over the established CPRI link,
mapping CPRI bit streams to RoE frames; and
de-mapping RoE frames to CPRI bit streams.

7. The method of claim 1 further comprising resetting a CPRI link between the proxy master and the radio equipment after Layer 1 synchronization between the proxy master and the radio equipment is achieved.

8. The method of claim 1 wherein the establishing the CPRI link comprises allowing CPRI link auto-negotiation operations to be performed between the radio equipment controller and the radio equipment to establish the CPRI link between the radio equipment controller and the radio equipment using the first link bit rate while the proxy master performs passive link monitoring operations, mapping operations, and de-mapping operations.

9. A proxy slave system for use in a fronthaul network environment comprising a radio equipment connected to a proxy master, the proxy slave system connected to a radio equipment controller, and a fronthaul Ethernet network connecting the proxy master and the proxy slave system and for establishing a Common Public Radio Interface (CPRI) link between the radio equipment controller and the radio equipment over the fronthaul Ethernet network;
the proxy slave system comprising at least one memory element for storing data; and
at least one processor for executing instructions associated with the data, wherein executing the instructions causes the proxy slave system to perform operations, comprising:
receiving, from the radio equipment controller, a first CPRI bit stream transmitted at a first plurality of link bit rates at respective transmit time intervals;
attempting to decode, at the proxy slave system, the first CPRI bit stream at a second plurality of link bit rates at respective reception time intervals;
on achieving hyper frame number synchronization (HFNSync) at a first link bit rate of the second plurality of link bit rates, mapping the first CPRI bit stream to one or more Radio over Ethernet (RoE) frames, wherein at least one of the one or more RoE frames comprises a header indicating the first link bit rate;
transmitting the one or more RoE frames to the proxy master;
on receiving one or more RoE frames from the proxy master, wherein the one or more RoE frames received from the proxy master comprise a second CPRI bit stream transmitted by the radio equipment:
de-mapping the one or more RoE frames received from the proxy master; and
transmitting the second CPRI bit stream to the radio equipment controller at the first link bit rate; and

upon HFNSync being achieved between the proxy slave system and the radio equipment controller using the first link bit rate, establishing the CPRI link using the first link bit rate.

10. The proxy slave system of claim 9 wherein the CPRI link is established within one transmit time interval of the radio equipment controller.

11. The proxy slave system of claim 9 wherein the operations are repeated until the radio equipment controller achieves the hyper frame number synchronization for the second CPRI bit stream transmitted by the proxy slave system at the first link bit rate.

12. The proxy slave system of claim 9 wherein the first and second plurality of link bit rates are synchronized to have a common subset of link bit rates.

13. The proxy slave system of claim 9 wherein the operations further comprise transmitting Radio over Ethernet (RoE) frames between the proxy master and the proxy slave system using the established CPRI link.

14. The proxy slave system of claim 9 wherein the operations further comprise: over the established CPRI link,
mapping CPRI bit streams to RoE frames; and
de-mapping RoE frames to CPRI bit streams.

15. The proxy slave system of claim 9 further comprising resetting a CPRI link between the proxy master and the radio equipment after Layer 1 synchronization between the proxy master and the radio equipment is achieved.

16. The proxy slave system of claim 9 wherein the establishing the CPRI link comprises allowing CPRI link auto-negotiation operations to be performed between the radio equipment controller and the radio equipment to establish the CPRI link between the radio equipment controller and the radio equipment using the first link bit rate while the proxy master performs passive link monitoring operations, mapping operations, and de-mapping operations.

17. One or more non-transitory computer-readable storage media encoded with instructions for a proxy slave in a fronthaul network environment comprising a radio equipment controller connected to the proxy slave, a proxy master connected to a radio equipment, and a fronthaul Ethernet network connecting the proxy master and the proxy slave, and for establishing a Common Public Radio Interface (CPRI) link between the radio equipment controller and the radio equipment over the fronthaul Ethernet network;
the instructions, when executed by a processor, cause the processor to perform operations comprising:
receiving, at the proxy slave from the radio equipment controller, a first CPRI bit stream transmitted at a first plurality of link bit rates at respective transmit time intervals;
attempting to decode, at the proxy slave, the first CPRI bit stre

Assignees

• Cisco Tech Inc

Inventors

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

Classifications

• H04J3/0658

  Clock or time synchronisation among packet nodes · CPC title

• H04W92/10

  between terminal device and access point, i.e. wireless air interface · CPC title

• H04W92/12

  between access points and access point controllers · CPC title

• H04W56/0005 Primary

  synchronizing of arrival of multiple uplinks · CPC title

• H04J3/0647

  Synchronisation among TDM nodes · CPC title