公开(公告)号：US20220232499A1

公开(公告)日：2022-07-21

申请号：US17714540

申请日：2022-04-06

Applicant: Cisco Technology, Inc.

Inventor： Prashant Anand ,  Manoj Kumar ,  Sudhir Kayamkulangara ,  Dinuraj K ,  Manigandan Boopalan

IPC: H04W56/00 ,  H04W76/10 ,  H04W28/22

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.

公开(公告)号：US20210084541A1

公开(公告)日：2021-03-18

申请号：US16906315

申请日：2020-06-19

Applicant: Cisco Technology, Inc.

Inventor： Prashant Anand ,  Manoj Kumar ,  Sudhir Kayamkulangara ,  Dinuraj K ,  Manigandan Boopalan

IPC: H04W28/22 ,  H04W28/04

Abstract: Techniques are described to provide for state machine handling at a proxy node in an Ethernet-based fronthaul network. In one example, a method includes performing, by a proxy node of a fronthaul network, negotiation operations associated with establishing a Common Public Radio Interface (CPRI) communication link between radio devices of the fronthaul network, wherein the negotiation operations comprise Layer 1 synchronization operations and Radio over Ethernet (RoE) validation operations for one or more link bit rates; and facilitating communications between the radio devices at a matching link bit rate upon completion of the negotiation operations.

公开(公告)号：US20210075532A1

公开(公告)日：2021-03-11

申请号：US16751509

申请日：2020-01-24

Applicant: Cisco Technology, Inc.

Inventor： Prashant Anand ,  Sudhir Kayamkulangara ,  Dinuraj K ,  Manigandan Boopalan ,  Manoj Kumar

IPC: H04J3/06 ,  H04L29/06

Abstract: Techniques are described to provide for re-timing a packetized radio flow to clean noise induced by packet delay variation of a packet network. In one example, a method includes receiving, at a first node of a fronthaul network, a Radio over Ethernet (RoE) frame transmitted by a second node in which the RoE frame comprises a Common Public Radio Interface (CPRI) bit stream associated with a first radio device, a sequence number, and a first time stamp. The method may further include generating a second time stamp by the first node upon obtaining the RoE frame; calculating an induced delay value based, at least in part, on the first time stamp and the second time stamp; calculating a re-timing value based on a re-timing interval and the induced delay value; and transmitting the CPRI bit stream to a second radio device based on the re-timing value.

公开(公告)号：US20210051494A1

公开(公告)日：2021-02-18

申请号：US16543344

申请日：2019-08-16

Applicant: Cisco Technology, Inc.

Inventor： Prashant Anand ,  Manoj Kumar ,  Sudhir Kayamkulangara ,  Manigandan Boopalan ,  Dinuraj K.

IPC: H04W24/04 ,  H04L12/24

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.

公开(公告)号：US20200252893A1

公开(公告)日：2020-08-06

申请号：US16435974

申请日：2019-06-10

Applicant: Cisco Technology, Inc.

Inventor： Prashant Anand ,  Manoj Kumar ,  Sudhir Kayamkulangara ,  Dinuraj K ,  Manigandan Boopalan

IPC: H04W56/00 ,  H04W76/10

Abstract: Techniques associated with link establishment in a fronthaul network are described herein. In one embodiment, a method includes receiving, by a proxy node, a Common Public Radio Interface (CPRI) bit stream transmitted by a radio equipment controller, wherein the CPRI bit stream is transmitted within a transmit time interval of the radio equipment controller; and fast-sampling, by the proxy node, the CPRI bit stream to determine whether a hyper frame number synchronization with the radio equipment controller at a common matching link bit rate is achievable, wherein the fast-sampling comprises attempting to decode the received CPRI bit stream and achieve the hyper frame number synchronization for each of a plurality of link bit rates configured for a fast-sampling time period during at least one fast-sampling time interval configured for the proxy node.