REC–RE CPRI Fronthaul Link Establishment via Proxy Fast-Sampling
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Solution Overview
Problem
Current CPRI link negotiation processes prescribed by CPRI Specification v7.0 do not work in fronthaul networks, where REC and RE are interconnected through intermediate Ethernet nodes, leading to discontinuity and inefficiency in establishing end-to-end CPRI link synchronization.
Innovation Solution
Implementing a mechanism for CPRI link establishment in Ethernet-based fronthaul networks using proxy nodes (Proxy Slave and Proxy Master) that perform fast-sampling and RoE frame enhancements to facilitate deterministic end-to-end CPRI link synchronization between REC and RE, including RoE header modifications to convey link bit rate information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional CPRI link negotiation processes are used in fronthaul networks with intermediate Ethernet nodes, then compatibility with existing CPRI equipment is maintained, but link establishment becomes unreliable and synchronization cannot be achieved
Solution Approach 1:
The patent introduces proxy nodes (Proxy Master and Proxy Slave) as intermediary devices between the REC and RE in Ethernet-based fronthaul networks. These proxies perform fast-sampling of CPRI bit streams and generate RoE frames with embedded synchronization information, enabling reliable link establishment across Ethernet networks while maintaining compatibility with traditional CPRI equipment at the endpoints.
Solution Approach 2:
The patent modifies the RoE frame structure by embedding hyper frame number synchronization information and link bit rate parameters directly in the RoE headers. This parameter embedding enables the negotiation and synchronization of CPRI links over Ethernet by conveying critical timing and rate information that traditional CPRI negotiation cannot provide across intermediate nodes.
2Loss of time
If fast-sampling and RoE frame enhancements are implemented, then deterministic end-to-end CPRI link synchronization is achieved, but device complexity increases
Solution Approach 1:
The patent implements preliminary action by having proxy nodes pre-sample CPRI bit streams at multiple possible link bit rates and pre-generate RoE frames with embedded synchronization information before actual link establishment is needed. This allows the system to quickly determine the correct synchronization parameters without lengthy negotiation processes, reducing link establishment time despite increased processing complexity.
Data Source
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AI summary
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.