ATLANTIC PAW

Advanced transmission language and allocation of new technology for international commu-nications and the proliferation of allied waveforms, ATLANTIC PAW (A-PAW), is a coop-erative international (UK, FR, GE, and US) project to provide interoperability between newly fielded international radios and allow backward compatibility to existing radio systems. A-PAW is an outgrowth and sequel to the previously discussed FM3TR effort. SDRs themselves will not provide all the anticipated benefits without the suite of tools required to expedite changes and new capabilities. The other side of the coin for SDR is the actual software application and the environment under which it is created and managed. A-PAW will develop a common description language, to be employed by all four countries. It will capture wave-form specifications, at a high level, and allow the output to be interpreted and coded for each nation’s own, dissimilar, programmable radio. This will enable new waveforms to be devel-oped and in an efficient manner, see Figure 2.28.

There are many tools available that attack small areas of the overall problem set but they are not integrable. What is required is the development of an executable specification. The specification itself must be comprehensive enough to capture all the air interface and protocol interoperability requirements. The UK is developing a common description specification language, or a waveform description language (WDL) [13]. Each nation then is expected to develop its own interpreter to transform the WDL output into the implementation-specific details needed to be hosted on national SDR assets. The output will have automatic code generation, which enables direct downloading to the target platforms.

As of this writing, the project consists of a number of tasks, which are shared by the US, UK, FR, and GE. One is the WDL itself, which is the responsibility of the UK. The US leads the task to define the waveform parameter database and structure. Then employing the WDL, the FM3TR enhanced waveform (French led) and the SATURN legacy waveform (German led) will be defined. FM3TR and SATURN waveforms are planned to be

imple-mented onto each nation’s respective platform. The culmination of A-PAW will be an international compatibility demonstration using both national SDRs and legacy SATURN radios.

2.8.4 Software Radio Development System (SoRDS) [14]

The SoRDS-2000 (refer to Figure 2.29) evolved from the initial equipment developed in 1999 to support the international FM3TR testing in Germany.

It was developed to serve as a testbed for the development, evaluation, and verification of software communications waveforms and algorithms. SoRDS is expected to provide enhanced capabilities, including ‘smart radio’ functions to JTRS-like equipment to meet the growing requirements of US military communications. Smart radio functions include bandwidth-efficient covert and jam resistant waveforms, adaptive data rate control, artifi-cially intelligent wireless link and network management, information assurance, and quality of service techniques. SoRDS-2000 needs to have the processing power to develop and evaluate very complex and computationally difficult algorithms. Therefore, a high perfor-mance, parallel processing, real-time capability is mandatory. SoRDS-2000 implements a modular and scalable ‘Beowulf’ architecture (refer to Figure 2.30).

There are four independent single board computers each containing a processor, memory, interface bus, and network interconnect to a host computer via a network switch. Each of these can communicate with each other and other devices on the network. SoRDS-2000 uses a homogeneous cluster of four Compaq (DEC) Alpha 667 MHz processors that have dual independent 100BaseT network interfaces and a PCI mezzanine card (PMC) interface. The host operates under a Linux OS, which supports a parallel processing, message passing

Figure 2.28 Waveform development executable specification

Figure 2.30 SoRDS block diagram

Figure 2.29 Software radio development system (SoRDS)

interface (MPI), environment. The SoRDS equipment uses a GPS PMC for timing, and audio PMC for voice and video. There are also two adaptive computing (Xilinx Virtex FPGAs) PMCs for higher speed processes and RF control. SoRDS-2000 is a two-channel system and utilizes a miniature radio codec (MRC), developed and manufactured by Rockwell Collins under the GloMo program, for each channel. A control and data interface module was developed for the MRCs and programmed in VHDL, as was the modem firmware for the FPGAs. SoRDS-2000 is supporting many initiatives at AFRL’s Information Directorate, in Rome, New York.

2.9 Conclusions

This chapter has provided a comprehensive history of the evolution of software radio and the way in which over many years defense requirements have been a major driver and funder of software radio. From what today might be seen as quite primitive initiatives fully flexible systems have now been demonstrated, deployed, and are being procured. The US government decision to request the establishment of the MMITS Forum was, with hindsight, a pivotal point in defense initiatives transitioning into the public arena which, together with the subse-quent market pull stimulated by the advent of 3G wireless, has seen software radio grow in acceptance and importance in the commercial marketplace.

Defense initiatives in software radio however, as have been outlined, continue and, unhin-dered by some of constraints of consumer market requirements, are continuing to push back the technological boundaries to establish new possibilities and methodologies which may also in due course find their way into consumer markets.

Acknowledgements

The help and support of several key individuals in providing detailed background material in the preparation of this chapter are gratefully acknowledged. Notably: information for Section 2.1.3 on ICNIA was drawn from a memorandum authored by M. Minges and J.

Arnold of AFRL; information for Section 2.3.5 was drawn from the MBMMR final report (dated July 2, 1993) provided to Mr George Singley by J. Oneffur and Major R. Nelson of CECOM/RDEC; Section 2.7.4 was written by Mr Donald W. Upmal WRN Project Leader, US Army Communications & Electronics Command, Fort Monmouth, New Jersey.

References

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[9] Programmable modular communications system (PMCS) guidance document, Revision-2, July 31, 1997, http://www.jtrs.sarda.army.mil/docs/pmcsgd.html

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jcit/

[11] Ruth, Robert, DARPA ITO, global mobile information systems, http://www.darpa.mil/ito/research/glomo/

[12] Digital modular radio AN/USC-61 (V) primer, http://c4iweb.spawar.navy.mil/pmw179/DMR_primer.htm [13] Willink, E., ‘The waveform description language’, in Tuttlebee, W.H.W. (Ed.) Software Radio: Enabling

Technologies, Wiley, Chichester, 2002.

[14] Reichhart, S. Benfey, D. and Youmans, B., SoRDS: platform for voice/video/network radio, Milcom’01.

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The Software Defined Radio