The trend toward software-defined radio (SDR) has made software portability an increasingly important topic. A number of chip, system and software companies have formed a portability working group within the SDR Forum industry consortium. The focus of the new Hardware Abstraction Layer Working Group is portability of high-speed signal-processing firmware.
SDRs replace the fixed-function hardware of a radio with programmable devices, thereby reducing the cost of multifunction radios, enabling upgrades and bug fixes in the field, reducing design risk and shortening time-to-market. As a result of this design, the signal-processing firmware for SDRs is expensive and, if the RF standard is sophisticated, potentially complex.
Moreover, there can be a lot of it: One manufacturer's military-oriented SDR product line has almost 3 million lines of code to support approximately 20 RF standards.Clearly, portability is vital to containing firmware costs acr oss a family of products. More subtly, it is essential for performance. Without it, the high firmware investment in SDR prevents the platform evolution needed to exploit improvements in component technology.
Achieving portability for radio firmware is a challenging task. Designers of signal-processing subsystems exploit FPGAs, DSPs, advanced reconfigurable logic and system-on-chip solutions to meet extreme performance demands. Few of these processing platforms support portable source representations. In cases where software tools are available, the technology is either immature or not yet trusted to produce efficient results.
The SDR Forum's Hardware Abstraction Layer Working Group brings together representatives of the many parties interested in solving this problem, including component vendors Intel, STMicroelectronics and Xilinx; radio makers BAE Systems and General Dynamics; radio software vendor Vanu; platform integrators Mercury Computers and Spectrum Signal, and other vendors such as Sandbridg e, Sarnoff and Mitsubishi.
The group is currently drafting a request for information (RFI) for release in mid-April. The goal is to investigate and report on as many relevant technologies as possible, including software tools, modeling and verification methods, test environments, libraries, standard ap- plication programming interfaces, source representations and others.
It seems unlikely that there is a silver-bullet solution. Instead, the HAL Working Group expects to discover a variety of technologies that assist with various parts of the problem. Therefore, a product that applies to only a limited range of hardware parts, or a certain restricted aspects of radio firmware, is still of interest.
The group expects to present its findings in a September report. All interested parties, whether or not they are members of the SDR Forum, are encouraged to sign up for the RFI distribution list.
John Chapin, Chief Technology Officer of Vanu Inc. (Cambridge, Mass.), chairs the SDR Forum's HAL Working Group.