Experts in Test
and Measurement

Networking the Fronthaul

The dark fibre used by CPRI connections is expensive to install, nor is it fully utilised by a CPRI connection. Some proposals were made to carry CPRI over WDM, enabling sharing of fibres between closely sited RRUs. However, the next major step in the evolution of fronthaul was to consider if the CPRI protocol could be transported across a shared network such as Ethernet.

The CPRI consortium created a new specification called eCPRI. They don’t actually specify what the “e” stands for, it could be for Ethernet (but it also works over IP), Evolved (but this was the term used to denote 4G over 3G) or Enhanced (which is my personal favourite). The eCPRI specification defines how to carry radio signals over a packet network. The underlying networks are not defined, but can include IP/UDP and/or Ethernet.

The IEEE are also in the process of creating an open standard for the same thing, designated IEEE1914. This is split into two parts, the radio over packet protocol (IEEE1914.4) and the requirements on the underlying transport network (IEEE1914.1). The main feature of both of these is that the functions of the basestation are split into three parts – the CU (Centralized Unit), the DU (Distributed Unit) and the RRU. One reason for this is that carrying a radio signal across a packet network is very inefficient, especially for 5G where the data rates are very high. The RRU connection may require a data rate of 25Gb/s or higher. The DUs can be located out in the network close the to RRUs. The connection from the CU to DU can be lower bandwidth, because carrying the raw data is more efficient than the encoded radio signal. This connection is sometimes referred to as the “middlehaul”.



A second reason is that some functions are very latency sensitive, limiting the length of the connection to a few kms, as with the original CPRI interface. If those functions are located in the DU, the less latency sensitive portions of the basestation function can be located further back in the network. This last piece enables the transition from Centralized RAN to Cloud RAN – the CUs can be located anywhere in the network, not just in a localized “baseband hotel”.

Tim Frost, Strategic Technology Manager, Calnex Solutions.

PRESS RELEASE

Proven 25/100GbE SyncE Reference Design from Silicon Labs, Calnex and Marvell

Austin,Texas, Linlithgow, UK – May 15, 2018

– Silicon Labs (NASDAQ: SLAB) and Calnex Solutions today announced a proven reference design for ITU-T G.8262-compliant Synchronous Ethernet (SyncE) applications at 25G and 100G Ethernet rates. The solution is based on the Marvell® Alaska® C family of high-speed Ethernet transceivers, Silicon Labs’ Si5348 low-jitter network synchronizer clock and the Calnex Paragon-100G test platform.

Cisco VNI forecasts mobile data traffic is expected to grow at a compound annual growth rate of 46 percent between 2016 and 2021. This transition is driving service providers to deploy higher capacity 25GbE and 100GbE links to backhaul mobile data from wireless base stations to metro/core optical networks. 4G and 5G networks have stringent requirements for phase and frequency synchronization to mitigate interference and more effectively share user bandwidth between adjacent cell sites. Mobile backhaul and fronthaul networks will use a combination of IEEE® 1588 and SyncE to distribute phase and frequency synchronization across the network. The joint Silicon Labs and Marvell solution enables equipment providers to extend SyncE to their highest speed backhaul and fronthaul networks and design with confidence using a proven solution for packet network synchronization.

“Carriers and data center operators are responding to the insatiable demand for video streaming and mobile data by transitioning to higher speed Ethernet networks,” said James Wilson, Senior Marketing Director for Silicon Labs’ timing products. “Silicon Labs is excited to partner with Marvell and Calnex to offer a proven, SyncE-compliant solution for 25/50/100/200/400GbE designs.”

The joint solution uses Silicon Labs’ Si5348 low-jitter network synchronizer in combination with the Marvell Alaska C 88X5123 and 88X5113 25GbE/100GbE industrial temperature-capable Ethernet transceivers. The Si5348 synchronizer, a part of Silicon Labs’ growing portfolio of high-performance network synchronization products, is the industry’s lowest jitter, most highly integrated clock solution for Synchronous Ethernet. The device’s industry-leading jitter performance of 100 fs rms (typ) optimizes transceiver performance and helps minimize system-level bit-error rates. The device supports three fully independent, frequency flexible DSPLLs, enabling a single clock IC to support SyncE clock synchronization and clock generation as well as general-purpose timing for FPGAs, processors and other devices.

The solution was tested using the Calnex Paragon-100G, a fully SyncE-compliant test platform that provides automated wander, jitter, transient and IEEE-1588 precision time protocol testing with industry-leading measurement precision. The overall solution, including the network synchronizer and Ethernet transceiver, was fully tested for compliance with ITU-T G.8262. Test results show that the solution has significant margin to G.8262 Ethernet Equipment Clock (EEC) Option 1 and Option 2 jitter generation and jitter tolerance requirements. The design is optimized to minimize phase transients caused by a protection switch (e.g., a fiber cut). The resulting solution provides significant margin to both current ITU-T G.8262 specifications as well as the more stringent G.8262.1 enhanced EEC standards currently in development. For a copy of this SyncE compliance report, visit www.silabs.com/synce-reference-design.

“Mobile backhaul is becoming an important application for Marvell’s Alaska C 100GbE/25GbE transceivers, and Marvell is delighted to be a part of the Silicon Labs’ ITU-T G.8262 compliant solution for this market,” said Ron Cates, Senior Director for Marvell’s Ethernet PHY product line.

“Clocking technologies like SyncE and precision time protocol (PTP) give carriers, webscale companies and data centers the ability to offer high-value services for applications like video and mobile data,” said Anand Ram, Vice President of Marketing at Calnex. “This approach only works if the performance of SyncE and PTP is proven at higher speeds including 25G, 100G and beyond. With this testing project, Silicon Labs, Marvell and Calnex have proven that we fully comply with SyncE standards, enabling hardware engineers to design 25GbE/100GbE systems with confidence using this joint solution.”

For more information about Silicon Labs’ network synchronization solutions, visit www.silabs.com/products/timing/clocks/network-synchronizer-clocks.

For more information about the Calnex Paragon-100G, visit www.calnexsol.com/en/solutions-en/paragon-100g

About Calnex Solutions
Calnex Solutions is a leading provider of R&D test solutions for telecom synchronization technologies. The company serves customers in more than 65 countries, including many of the largest telecom companies in the world. Information about Calnex is available on the Web at www.calnexsol.com.

About Silicon Labs
Silicon Labs (NASDAQ: SLAB) is a leading provider of silicon, software and solutions for a smarter, more connected world. Our award-winning technologies are shaping the future of the Internet of Things, Internet infrastructure, industrial automation, consumer and automotive markets. Our world-class engineering team creates products focused on performance, energy savings, connectivity and simplicity. www.silabs.com.

PRESS RELEASE

Calnex Solutions acquires JAR Technologies

LINLITHGOW, SCOTLAND, 29th March 2018

Calnex Solutions today announced the acquisition of JAR Technologies headquartered in Belfast, Northern Ireland. The acquisition, which is for an undisclosed amount, increases the Calnex product portfolio to include JAR’s portfolio of multi-port, multi-user Network Emulators complementing Calnex’s existing Attero product line of network emulators.

JAR Technologies supplies the JAR:Emulate product range of scalable Network Emulators supporting interface rates from 100BT to 40GbE. The JAR:Emulate products are used in a wide variety of networks and applications including Mobile, WAN verification, Data Center relocation, Military/Security, Smart-Grid Utilities, Healthcare and Broadcast Communications as well as Video Conferencing Communications.

“SD-WAN, Cloud/OTT and Data Centers are hot new application areas for Network Emulation,” said Tommy Cook, CEO of Calnex Solutions. “These application areas require products with flexibility & high port count. The acquisition of JAR Technologies enables Calnex to effectively address these key applications as the JAR:Emulate product line provides this flexibility with its scalable, multi-port, multi-user platform.”

“The Calnex acquisition of JAR Technologies enables the JAR:Emulate product line to reach a much broader range of customers and applications,” said Ryan McAnlis, CEO of JAR Technologies.

More information on JAR Technologies is available on the Web at www.jaremulate.com.

About Calnex Solutions
Calnex Solutions is a leading provider of R&D test solutions for telecom synchronisation technologies. The company serves customers in more than 45 countries, including many of the largest telecom companies in the world. Information about Calnex is available on the Web at www.calnexsol.com.

About JAR Technologies
JAR Technologies is a leading provider of scalable Network Emulators for telecoms, IT, datacenter/cloud, video, SD-WAN and security applications. The products are also used in smart grid utilities, healthcare and many other applications. Information about JAR Technologies is available on the Web at www.jaremulate.com

EDITORIAL CONTACT:
Tommy Cook, CEO, Calnex Solutions
+44 (0)1506 671416
tommy.cook@calnexsol.com