History of the Forum and the SCA

The Software Communications Architecture, or SCA, provides a set of specifications “that facilitate portability, interoperability and configurability of the software and hardware components used in the manufacturing of radio systems”[1]. The original technologies for these specifications were developed in the late 1980’s and early 1990’s with the first public release of a consolidated specification occurring through the Forum’s Technical Report Version 1.0 in 1997 as the “Software Radio Architecture (SRA)”[2]. The SRA architecture was matured in the Forum’s Technical Report Version 2.1 entitled ““Architecture and Elements of Software Defined Radio Systems as Related to Standards”[3], and was further matured by the members of the Modular Software Programmable Radio Consortium (MSRC), working in cooperation with the Forum’s Mobile Working Group into what became the Joint Tactical Radio System Software Communications Architecture (JTRS SCA).

In 2002, the Forum abandoned support of the SRA in favour of the publically available SCA release adopted by the JTRS Program.  From 2002 to 2009, the Forum was active in supporting the evolution of the SCA and related specifications around the world, first through its Mobile Working Group (2002 to 2005) and then through the SCA Work Group (2005 to 2009):

  • API Position Paper (SDRF-03-R-0005-V1.0.0)
  • Submission to JTRS JPO from SDR Forum regarding DSP and FPGA portability standardization effort (SDRF-04-R-0003-V1.0.0)
  • SDRF Change Proposals and Comments on JTRS SCA 3.0 Specialized Hardware Supplement (SDRF-05-R-0001-V1.0.0)
  • Comments on Software Communications Architecture Specification Version 2.2.2 (SDRF-06-R-0012-V1.0.0)
  • Request for Information Regarding Reference SDR (SDRF-06-RFI-0007)
  • SCA Test and Evaluation Request for Information (SDRF-07-RFI-0017-V1.0.0)
  • Endorsement of JTRS SCA 2.2.2 (SDRF-08-R-0006-V1.0.0)
  • Test and Certification Guide for SDRs based on SCA - Part 1: SCA (SDRF-08-P-0007-V1.0.0)
  • Support for “Three Category” Approach for Software Communications Architecture (SCA) Standards (WINNF-09-R-0023-V1.0.0)

In 2009, the Forum was designated as the Public Liaison for the development of the “SCA Next” architecture, and began working with the international community to provide input to this next evolution of the SCA Specification[4]. Contributions to this effort were made by member organizations world wide and programs such as ESSOR. Documents submitted to the JTRS SCA Next Working Panel as a result of these efforts included 5 requests for comment and 3 recommendations as follows:

Requests for Comment Recommendations

Request for Comment on Generalization of the Resource Factory Concept Working

Document WINNF-10-RFI-0005

WINNF Approved Issues and Resolutions concerning the November 2010 draft of the SCA Next Specification

Document WINNF-11-R-0004

Request for Comment on Amendment to CORBA Profile for SCA Next AddingORB_init parameters

Document WINNF-10-RFI-0006

Change proposal to Draft SCA Next AEP (Appendix B) for Harmonization with ESSOR Architecture

Document WINNF-10-R-0005

Request for Comment on Amendment to CORBA Profile for SCA Next Adding Lightweight

Document WINNF-10-RFI-0004  

Change Proposal to Draft SCA Next CORBA Profiles for Harmonization with ESSOR Architecture

Document WINNF-11-R-0006

Request for Comment on SCA Implementers Work Group Change Proposals for SCA Next

Document WINNF-10-RFI-0003


Request for Comment on CORBA Profile for SCA Next Document

Document WINNF-10-RFI-0002 



In 2010, the Forum underwent an Organization Transformation that included the formation of a Coordinating Committee on International SCA Standards (CC SCA)[5]. The mandate of the CC SCA is to support the harmonization of the SCA standards in the first category at the international level for the mutual benefits of all stakeholders to include:

  • Defining an industry driven SCA evolution roadmap for the international community
  • Profiling the SCA specification and related APIs to define internationally accepted variants that are hosted by the Forum
  • Developing extensions to the SCA standards that address any gaps between the defined SCA evolution roadmap and Forum accepted SCA specification variants
  • Providing implementation and certification guides, tools etc. easing implementation and supporting proliferation
  • Establishing and managing industry led certification programs where appropriate
The Committee is led by a Steering Group working in collaboration with an Advisory Council to execute on an agreed upon "Coordination Model for International SCA Standards" (Document WINNF-10-R-0018). Following this model, in 2012 the committee participated in the vote by JTRS to approve the SCA 4.0 (formerly SCA Next) specification [6]. 


In addition to its work in support of SCA Next, from 2010 to 2013, the CC SCA developed, balloted and approved a number of other work products:  
In November 2013 the evolution of the SCA continued through a workshop hosted by the CC SCA and with participation from the JTNC to explore areas to further improve the SCA specification [7]. Key areas for additional improvement defined at this workshop included better backwards compatibility with SCA 2.2.2 and additional updates to the Application Environment Profiles (AEPs) and Interface Definition Language (IDL) profiles. A work plan was established, with the CC SCA taking the lead in developing technical solutions in multiple areas. Committee member representatives donated over 1000 hours to produce six recommendations and two specifications to be sumitted to the JTNC:


Recommendations Specifications

Application Backwards Compatibility

Document WINNF-14-R-004-V1.0.0  


Document WINNF-14-S-0009-V1.0.0 

Application Mixture

Document WINNF-14-R-0014-V1.0.0


Document WINNF-14-S-0016-V1.0.0

Naming Conventions

Document WINNF-14-R-0013-V1.0.0


Push Registration Allocation Properties

Document WINNF-14-R-0012-V1.0.0


Scalable Components

Document WINNF-14-R-0010-V1.0.0


Scalable Manager Components

Document WINNF-14-R-0011-V1.0.0




[1] https://winnf.memberclicks.net/assets/documents/cc sca charter v3 0 0 - 23 october 2012.pdf  

[2] http://en.wikipedia.org/wiki/Wireless_Innovation_Forum, http://groups.winnforum.org/d/do/2991 and http://groups.winnforum.org/d/do/2992

[3] http://groups.winnforum.org/d/do/1725

[4] http://jtnc.mil/sca/Documents/JPEO-NR-2010-004.pdf  

[5] http://data.memberclicks.com/site/sdf/SDR_Forum_2010_to_2014_Strat_Plan.pdf

[6] http://groups.winnforum.org/d/do/5353 and http://jtnc.mil/sca/Documents/pressrelease/SCA_4_SCA_site.pdf

[7] http://groups.winnforum.org/p/cm/ld/fid=403