SpeakEasy
Encyclopedia
SpeakEasy was a United States military project to use software-defined radio
technology to make it possible to communicate with over 10 different types of military radios from a single system.
According to Upmal and Lackey in “SPEAKeasy, the Military Software Radio” IEEE Communications Magazine
(NY: IEEE Press) 1995, the SpeakEasy project was started in 1991 and was the first large-scale software radio. SpeakEasy was motivated in large part by the communications interoperability problems that resulted from different branches of the military services having dissimilar (non-interoperable) radio systems. This lack of communications interoperability can be directly linked to casualties in several conflicts. SpeakEasy had a very aggressive goal of implementing ten different radio waveforms in software on a single platform. The designers chose the fastest DSP
available at the time, the Texas Instruments TMS320C40
processor, which ran at 40 MHz. Since this was not enough processing power to implement all of the waveform processing, the system boards were designed to each support four ’C40s as well as some FPGAs
.
In 1994, Phase I was successfully demonstrated; however it involved several hundred processors and filled the back of a truck. Moore’s Law provides a doubling in speed every eighteen months, and since it had taken three years to build the system and write all of the software, two doublings had taken place. This seemed to indicate that the number of processors could be reduced by a factor of four. However, SpeakEasy could not take advantage of these newer faster processors, and the reason was the software.
The software was tied to ’C40 assembly language, plus all of the specialized glue code
to get four C40s to work together with the code for the particular chosen FPGA. The observation was that it had taken three years to write software for a platform that Moore’s Law made obsolete in eighteen months. Further-more, a software radio pushes most of the complexity of the radio into software, so the software development could easily become the largest, most expensive part of the system. These observations led to software portability
being a key goal of the SpectrumWare project."
Software-defined radio
A software-defined radio system, or SDR, is a radio communication system where components that have been typically implemented in hardware are instead implemented by means of software on a personal computer or embedded computing devices...
technology to make it possible to communicate with over 10 different types of military radios from a single system.
History
"The SpectrumWare project applied a software-oriented wireless communications approach with distributed signal processing. The research direction of the SpectrumWare project was heavily influenced by two software radio efforts: the military SpeakEasy project and the commercial products of the Steinbrecher Corporation.According to Upmal and Lackey in “SPEAKeasy, the Military Software Radio” IEEE Communications Magazine
IEEE Communications Magazine
IEEE Communications Magazine deals with all areas of communications including light-wave telecommunications, high-speed data communications, personal communications systems , ISDN, and more...
(NY: IEEE Press) 1995, the SpeakEasy project was started in 1991 and was the first large-scale software radio. SpeakEasy was motivated in large part by the communications interoperability problems that resulted from different branches of the military services having dissimilar (non-interoperable) radio systems. This lack of communications interoperability can be directly linked to casualties in several conflicts. SpeakEasy had a very aggressive goal of implementing ten different radio waveforms in software on a single platform. The designers chose the fastest DSP
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
available at the time, the Texas Instruments TMS320C40
TMS320C4x
The TMS320C4x is the second generation of 32-bit floating point digital signal processors. The first family member, the TMS320C40, was introduced in 1990. TMS320C4x family members target multiprocessor floating-point DSP systems for scientific, industrial, and military applications...
processor, which ran at 40 MHz. Since this was not enough processing power to implement all of the waveform processing, the system boards were designed to each support four ’C40s as well as some FPGAs
Field-programmable gate array
A field-programmable gate array is an integrated circuit designed to be configured by the customer or designer after manufacturing—hence "field-programmable"...
.
In 1994, Phase I was successfully demonstrated; however it involved several hundred processors and filled the back of a truck. Moore’s Law provides a doubling in speed every eighteen months, and since it had taken three years to build the system and write all of the software, two doublings had taken place. This seemed to indicate that the number of processors could be reduced by a factor of four. However, SpeakEasy could not take advantage of these newer faster processors, and the reason was the software.
The software was tied to ’C40 assembly language, plus all of the specialized glue code
Glue code
In programming, glue code is code that does not contribute any functionality towards meeting the program's requirements, but instead serves solely to "glue together" different parts of code that would not otherwise be compatible...
to get four C40s to work together with the code for the particular chosen FPGA. The observation was that it had taken three years to write software for a platform that Moore’s Law made obsolete in eighteen months. Further-more, a software radio pushes most of the complexity of the radio into software, so the software development could easily become the largest, most expensive part of the system. These observations led to software portability
Software portability
Portability in high-level computer programming is the usability of the same software in different environments. The prerequirement for portability is the generalized abstraction between the application logic and system interfaces...
being a key goal of the SpectrumWare project."