White Paper

WHITE PAPER SOSA and VITA Working Together for Next-Gen Defense Systems mrcy.com 5 These modules must be based on open, published standards, with consensus-based influence stakeholders directing the evolution, and a strict conformance validation process. The SOSA Architecture protects IP (intellectual property) within the modules to incentivize innovation and competition. The SOSA Technical Standard documents the SOSA Architecture with detailed rules and requirements drawn and adapted from a collection of open standards. The primary standards defining specifications for plug- in cards, backplanes, chassis, electrical components, and mechanical structures are VITA standards. The SOSA Conformance Policy, now being defined by the SOSA Conformance Standing Committee, will define processes for qualifying products against the Technical Standard. They include multiple conformance verification processes, a single conformance certification process, and a single SOSA certified conformant product registration process. Until the award of certification, no product can claim to be SOSA conformant. Membership in SOSA is restricted to US citizens and organizations so that DoD-sensitive or classified requirements can be presented by representatives from the armed services to promote solution strategies within the SOSA Technical Standard. For this reason, technical details of on-going discussions in the SOSA Technical Working Group may not be disclosed to the public. Once the standard is approved and released to the public, it will contain only specifications and rules, free from the underlying, sensitive use drivers. VITA AND SOSA Because VITA is so central to the SOSA hardware definition, many of the same individuals in the SOSA TWG are also active participants in the VITA Standards Organization (VSO). Because restrictions on technical disclosures imposed on the TWG by SOSA do not apply to VSO, members of VSO must be mindful against referencing on-going SOSA technical topics in their VSO discussions and publications. Nevertheless, the TWG does release period "snapshots" of the evolving SOSA Technical Standard that are publicly available for review, the latest being Snapshot 3 released in July 2020. While no conformance to these snapshots may be claimed, they illustrate the direction and underlying principles guiding the final standard. In some cases, SOSA adopts only carefully selected subsets of existing VITA specifications. For example, the TWG adopted only a handful of the more than one hundred 3U and 6U OpenVPX slot and module profiles, based on an analysis that they could accommodate the majority of system requirements. User-defined backplane pins defined in OpenVPX pose a nemesis for standardization efforts because they allow custom assignment of signals with interface standards, directions, and voltages. Profiles with user-defined pins are being deprecated in SOSA. Instead, work is underway to assign a minimum set of specific I/O standards to each group of legacy user-defined pins for each of the OpenVPX control, data, and expansion planes. SOSA restricts the primary VPX power supplies to +12V only, prohibiting +5V, and +3.3V. This greatly simplifies the previous OpenVPX issue of balancing among three voltages to simplify chassis power supplies and standardize the plug-in cards. Unlike most OpenVPX systems, SOSA requires hardware platform management leveraging the HOST 3.0 system management architecture, which itself is highly leveraged from VITA 46.11. A system manager module accesses all SOSA system elements for census taking, health monitoring, trouble shooting, new firmware/ software upgrades, and reset/recovery operations. Backplane I/O for RF signals and optical interfaces in OpenVPX have gained significant traction in CMOSS, MORA, and HOST systems over the last six years, all enabled by VITA 66 and VITA Figure 2 Rear view of 3U OpenVPX Module with two VITA 67.3D backplane connectors, each with 10 coaxial RF signals and 24 optical lanes. Courtesy by TE Connectivity.

• Cover