IP Library Granted Patent US 12,652,626
Granted Patent B2
US 12,652,626 · App. 17/925,758 · Granted Jun 9, 2026

Clock selection in a fronthaul network

Inventors: Ramana Reddy Machireddy (Bangalore, IN); Sridhar Bhaskaran (Bangalore, IN); Manasi Padhy (Bangalore, IN); Antonio Forenza (San Mateo, CA)
Assignee: RAKUTEN SYMPHONY, INC.
H04W56/001
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Quick Facts
Patent No.
US 12,652,626
App. No.
17/925,758
Granted
Jun 9, 2026
Kind
B2
Abstract

In general, the current subject matter relates to clock selection in a fronthaul network. In some implementations, clock selection in a fronthaul network can include selecting one distributed unit (DU) from among a plurality of DUs communicatively coupled to a radio unit (RU) to serve as a primary clock for a communication system including the plurality of DUs, the RU, and a service management and orchestration (SMO), and transmitting a request to the RU that triggers the RU to select one of the DUs to become the primary clock. The SMO can be communicatively coupled to the RU and the plurality of DUs.

Claims (42)

1 . A computer-implemented method, comprising:

determining to switch a primary clock for a communication system from one distributed unit (DU), from among a plurality of DUs communicatively coupled to a radio unit (RU), the communication system including the plurality of DUs, the RU, and a service management and orchestration (SMO); and

based on the determining, transmitting a request that triggers the RU to select another DU of the plurality of DUs to become the primary clock,

wherein the SMO is communicatively coupled to the RU and the plurality of DUs, and

wherein the SMO determines to switch the primary clock for the communication system.

2 . The method of claim 1 , wherein the SMO transmits the request to the RU.

3 . The method of claim 1 , wherein the SMO transmits the request to the one DU to instruct the RU to perform the selecting.

4 . The method of claim 3 , wherein based on the transmitted request, the one DU requests the RU to select the other DU to become the primary clock.

5 . The method of claim 1 , further comprising receiving a signal from each of the DUs among the plurality of DUs capable of serving as the primary clock;

wherein the selecting is only among the plurality of DUs capable of serving as the primary clock.

6 . The method of claim 1 , wherein the one DU is serving as the primary clock at a time of or just prior to the selecting being performed; and

the method further comprises removing the one DU from consideration as being selected.

7 . The method of claim 6 , wherein the removing removes the one DU from the selecting by the RU and from future selecting.

8 . The method of claim 6 , wherein the determining is triggered by a failure of the one DU.

9 . The method of claim 1 , wherein the request is a remote procedure call (RPC) request.

10 . The method of claim 1 , wherein the communication system includes an Open Radio Access Network (O-RAN) architecture.

11 . The method of claim 1 , wherein a signal indicating that a DU is capable of serving as the primary clock is received from the DU upon the DU connecting to a fronthaul network, which triggers the DU to broadcast the signal.

12 . The method of claim 1 , wherein the determining is triggered by at least one of:

a notification received by the SMO from the one DU, the notification being transmitted in response to detection of an error by the one DU;

the one DU being offline or otherwise unable to communicate with a fronthaul network;

the one DU having been the primary clock for at least a predetermined amount of time; and

a predetermined selection order of the plurality of DUs.

13 . An apparatus, comprising:

at least one processor, and

at least one non-transitory storage media storing instructions that, when executed by the at least one processor, cause the at least one processor to perform operations comprising:

determining to switch a primary clock for a communication system from one distributed unit (DU), from among a plurality of DUs communicatively coupled to a radio unit (RU), the communication system including the plurality of DUs, the RU, and a service management and orchestration (SMO); and

based on the determining, transmitting a request that triggers the RU to select another DU of the plurality of DUs to become the primary clock,

wherein the SMO is communicatively coupled to the RU and the plurality of DUs, and

wherein the SMO determines to switch the primary clock for the communication system.

14 . The apparatus of claim 13 , wherein the SMO transmits the request to the RU.

15 . The apparatus of claim 13 , wherein the SMO transmits the request to the one DU to instruct the RU to perform the selecting.

16 . The apparatus of claim 15 , wherein based on the transmitted request, the one DU requests the RU to select the other DU to become the primary clock.

17 . The apparatus of claim 13 , wherein the operations further comprise receiving a signal from each of the DUs among the plurality of DUs capable of serving as the primary clock; and

the selecting is only among the plurality of DUs capable of serving as the primary clock.

18 . The apparatus of claim 13 , wherein the one DU is serving as the primary clock at a time of or just prior to the selecting being performed; and

the operations further comprise removing the one DU from consideration by the RU as being selected.

19 . The apparatus of claim 13 , wherein the request is a remote procedure call (RPC) request.

20 . At least one non-transitory storage media storing instructions that, when executed by at least one processor, cause the at least one processor to perform operations comprising:

determining to switch a primary clock for a communication system from one distributed unit (DU), from among a plurality of DUs communicatively coupled to a radio unit (RU), the communication system including the plurality of DUs, the RU, and a service management and orchestration (SMO); and

based on the determining, transmitting a request that triggers the RU to select another DU of the plurality of DUs to become the primary clock,

wherein the SMO is communicatively coupled to the RU and the plurality of DUs, and

wherein the SMO determines to switch the primary clock for the communication system.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 22, 2024
From: RAKUTEN SYMPHONY SINGAPORE PTE LTD
To: RAKUTEN SYMPHONY, INC.
Reel/Frame 068466/0598 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 18, 2024
From: ALTIOSTAR NETWORKS, INC.
To: RAKUTEN SYMPHONY, INC.
Reel/Frame 068023/0534 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 21, 2022
From: MACHIREDDY, RAMANA REDDY; BHASKARAN, SRIDHAR; PADHY, MANASI; FORENZA, ANTONIO
To: ALTIOSTAR NETWORKS, INC.; RAKUTEN SYMPHONY SINGAPORE PTE. LTD.
Reel/Frame 061838/0812 →
Continuity (1)
Related Publication 20240224202A1 · Jul 4, 2024
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