Telefonaktiebolaget Lm Ericsson (publ)

Cisco Technology, Inc.

Prashant Anand

Manigandan Boopalan

Sudhir Kayamkulangara

Dinuraj K

Manoj N Kumar

Mustafa Arisoylu

Vinayak Joshi

Ashish Anand

Ashutosh Bisht

Ashwani Kumar Mehra

Manoj Kumar

Himanshu Asnani

Ramanathan Lakshmikanthan

Rohith Basavaraja

Jayasenan Sundara Ganesh

Dharmarajan Subramanian

Myna Vajha

Arvind Mukundan

Nandan Mahadeo Sawant

Arun Balachandran

Ning Xu

Dirk Kampmann

Brian Alleyne

Albert Jining Tian

Vivek Srivastava

Jan Scheurich

Srikar Rajamani

Mark Hlady

Sun Den Chen

Sundar Ramakrishnan

Parthibhan Paramaguru

Vasudevan Visvanathan

Somesh Ubhayanandan Malimath

Ashok Chandre Gowda

Ajay Sandhir

Rohit Kumar Gupta

Abhishek Arora

Abhishek Chaudhary

Rajesh Ishwariah Balay

The present disclosure is directed to ensuring end-to-end packet delivery in a Common Public Radio Interface (CPRI) circuit with a high jitter packet-based fronthaul network. In one aspect, a method includes determining, at a de-mapper, that at least one data packet scheduled to be played out is not available; inserting an idle data packet into a buffer at the de-mapper for each data packet that is not available; continuously monitoring a packet playout process to (1) identify last valid data packet played out, (2) a number of idle data packets inserted, and (3) a number of data packets currently stored in the buffer; and determining that insertion of idle data packets into the buffer should be stopped and a valid data packet to be played out; wherein inserting the idle data packet and the valid data packet ensure link integrity in data packet transmission between two network elements.

Providing high assurance of end-to-end CPRI circuit in a high jitter packet based fronthaul network

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.

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

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.

This technology allows time synchronization in passive optical networks ('PON'). A first Ethernet device timestamps and transmits a packet to a second Ethernet device via the PON. The first Ethernet device transmits the packet to a small form-factor pluggable ('SFP') device within the PON and connected to the first Ethernet device. The SFP device determines a transmission time to a second SFP device and modifies a correction field ('CF') of the packet by subtracting an ingress time and the transmission time from the CF. The packet is transmitted to the second SFP device, which modifies the CF by the addition of an egress time. The modified CF value represents the real-time transmission delay incurred in the SFP devices. The packet is transmitted to a second Ethernet device to synchronize a clock using the timestamp and the CF value in accordance with the PTP/IEEE-1588 standard.

Time synchronization in passive optical networks

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.

Link fault handling in fronthaul communication networks

Techniques that provide link auto-negotiation between a radio equipment controller (REC) and a radio equipment (RE) are described herein. In one embodiment, a method includes performing, by a proxy master, a Common Public Radio Interface (CPRI) Layer 1 (L1) link auto-negotiation with a RE to achieve a L1 synchronization between the proxy master and the RE at a link bit rate; communicating the link bit rate from the proxy master to a proxy slave; performing, by the proxy slave, a CPRI L1 link auto-negotiation with a REC to determine whether a L1 synchronization between the proxy slave and the REC is achieved, wherein if the L1 synchronization is achieved, the link bit rate is a common matching link bit rate achieved; and upon the common matching link bit rate being achieved, establishing a CPRI link between the REC and the RE using the common matching link bit rate.

Link auto-negotiation between a radio equipment controller (REC) and radio equipment (RE) in an ethernet-based fronthaul network

A carrier-grade network address translation (NAT) gateway system includes a switch having a gateway function configured to receive packets that are communicated via its ingress and egress ports. The switch having the gateway function has a first link to a first NAT processing function and a second link to a second NAT processing function. The first NAT processing function has a first deterministic address/port translation function and a first mapping table for storing first binding entries. The second NAT processing function has a second deterministic address/port translation function and a second mapping table for storing second binding entries. Preferably, the first and the second deterministic address/port translation functions are the same. The switch is configured to communicate each received packet for processing at both the first and the second NAT processing functions (e.g., in either a serial manner or a parallel manner), which provides redundancy in state information.

Stateful redundancy for deterministic carrier-grade network address translation (NAT) services

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.

State machine handling at a proxy node in an Ethernet-based fronthaul network

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.

Re-timing a packetized radio flow to clean noise induced by packet delay variation of a packet network

State machine handling at a proxy node in an ethernet-based fronthaul network

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Bengaluru, India

Prashant Anand