AXIe Consortium Announces Optical Communication Standard for Instrumentation Systems

Posted Oct 05, 2017 by Prerit Tomar

The AXIe Consortium has announced a new specification, Optical Data Interface (ODI), suitable for high-speed instrumentation systems addressing challenging applications in 5G communications, mil/aero, and advanced communication research. The AXIe Consortium was joined by Conduant Corporation, Guzik Technical Enterprises, Intel Corporation, Keysight Technologies, Samtec Incorporated, and Xilinx in endorsing the standard and stating their plans to offer components or instrumentation products compliant with the new standard. Though managed by the AXIe Consortium, the new standard is not specific to AXIe, and works equally well with any instrument format, whether traditional bench instrument, or AXIe, LXI, or PXI modular design.

ODI is the abbreviation for Optical Data Interface, a new high-speed interface standard for advanced instrumentation and embedded systems. ODI breaks speed and distance barriers by relying on optical communication between devices, over a simple pluggable optical cable.

The ODI specification delivers data communication speeds simply not possible using electrical interconnects. Since it uses a small optical connector that can be placed on any instrument, it is not specific to the AXIe modular standard. For the benefit of the industry and users alike, they have decided to open it up for use by any vendor building products, regardless of form factor, and not restrict it to AXIe.

When you look at 5G or phased-array mil/aero applications, the aggregate bandwidth needed to transfer IQ data grows pretty rapidly. Electrical solutions can't even extend across a backplane, much less a racked system. But with optics, you can connect instruments up to 100 meters away if needed. The interoperability, bandwidth, and distance issues simply disappear. However, ODI is not simply a physical link standard. The AXIe Consortium has adopted the VITA 49 standards, which define data formats for software defined radios. This extends the applications from not just test and measurement, but to embedded designs as well.

The ODI standard leverages three layers of technology. The physical layer is defined as optical technology consisting of 12 lanes of 14.1 Gb/s each, enabling 20 GBytes/s per optical port. Multimode fiber cables connect ports together, using the standard MPO (Multi-fiber Push On) connector. Ports may be aggregated, with four ports delivering 80 GBytes/s. The protocol layer is defined by the Interlaken standard, a device interconnect standard common in data centers, conceived by Cortina Systems and Cisco Systems. Interlaken is supported by the major FPGA suppliers, and delivers arbitrary packets over any number of lanes. The top layer specifies packets defined by the VITA 49 family of standards, also known as VRT, VITA Radio Transport. VRT packets are sent between devices using standardized data formats and context packets.

Conduant, Guzik, and Keysight all announced their intent to deliver products with ODI interfaces. Component vendors also signaled their support for the standard.

A set of preliminary technical specifications is posted on the AXIe website, along with a technical overview. Any manufacturer may adopt the ODI specification, and a manufacturer may participate in the ODI Technical Committee by joining the AXIe Consortium.