Abstract: In one embodiment, an apparatus includes a chassis base, a printed circuit board mounted on the chassis base, a heatsink positioned over the printed circuit board to prevent corrosion of components on the printed circuit board, wherein the heatsink comprises a plurality of upward extending fins and a plurality of downward extending walls, a seal interposed between an edge of the downward extending walls and the chassis base, and a cover extending over the heatsink.

Abstract: A rack-mountable heat-exchanger for modular electronic systems is provided that include a heat exchanger including ambient air inlets and outlets forming an ambient airflow path in a first direction, and recirculating air inlets and outlets forming a recirculating airflow path in a second direction perpendicular to the first direction separated from the ambient airflow path; housing for an electronic device, the housing including internal air inlets and outlets forming an internal airflow path; a first duct configured to link the recirculating air outlet to the internal air inlet; a second duct configured to link the recirculating air inlet to the internal air outlet; and fan assemblies located one of the airflow path, configured to propel air through the heat exchanger in the respective airflow path.

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.

Abstract: A rack-mountable heat-exchanger for modular electronic systems is provided that include a heat exchanger including ambient air inlets and outlets forming an ambient airflow path in a first direction, and recirculating air inlets and outlets forming a recirculating airflow path in a second direction perpendicular to the first direction separated from the ambient airflow path; housing for an electronic device, the housing including internal air inlets and outlets forming an internal airflow path; a first duct configured to link the recirculating air outlet to the internal air inlet; a second duct configured to link the recirculating air inlet to the internal air outlet; and fan assemblies located one of the airflow path, configured to propel air through the heat exchanger in the respective airflow path.

Abstract: 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.

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.

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.

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.

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.

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.

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.

Abstract: A rack-mountable heat-exchanger for modular electronic systems is provided that include a heat exchanger including ambient air inlets and outlets forming an ambient airflow path in a first direction, and recirculating air inlets and outlets forming a recirculating airflow path in a second direction perpendicular to the first direction separated from the ambient airflow path; housing for an electronic device, the housing including internal air inlets and outlets forming an internal airflow path; a first duct configured to link the recirculating air outlet to the internal air inlet; a second duct configured to link the recirculating air inlet to the internal air outlet; and fan assemblies located one of the airflow path, configured to propel air through the heat exchanger in the respective airflow path.

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.

Abstract: In one embodiment, an apparatus includes a chassis base, a printed circuit board mounted on the chassis base, a heatsink positioned over the printed circuit board to prevent corrosion of components on the printed circuit board, wherein the heatsink comprises a plurality of upward extending fins and a plurality of downward extending walls, a seal interposed between an edge of the downward extending walls and the chassis base, and a cover extending over the heatsink.

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.

Abstract: In one embodiment, an apparatus includes a chassis base, a printed circuit board mounted on the chassis base, a heatsink positioned over the printed circuit board to prevent corrosion of components on the printed circuit board, wherein the heatsink comprises a plurality of upward extending fins and a plurality of downward extending walls, a seal interposed between an edge of the downward extending walls and the chassis base, and a cover extending over the heatsink.

Abstract: 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.

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.

Abstract: 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.

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.