The TIREM RF Pathloss program model predicts radio frequency strength over irregular terrain. The U.S. Army Research Lab (ARL) requested that Engility contractors, working in DOD’s High Performance Computing Modernization Program (HPCMP) under the User Productivity, Technology Transfer and Training (PETTT) Program improve the performance of the TIREM RF Pathloss program. The performance of the code was to match or exceed 65,535 pathloss calculations per second using 256 radios in transmit and receive mode in under 0.5 seconds. The rate was assumed to set the performance metric for real-time operation.
ARL requested that changes to the FORTRAN source not be significantly altered to maintain its baseline configuration. To minimize the changes to the source code, the TIREM program was accelerated using the hybrid method of MPI + OpenMP. Engility engineers removed the data race conditions that existed in the original version of the source code. As a result, the ARL performance level was easily met. For weak scalability above a single node, MPI was added to OpenMP and achieved over 2.3 million pathloss calculations per second using 16 Excalibur nodes. Excalibur is a Cray XC40 located at the ARL DoD Supercomputing Research Center. This work illustrated that TIREM is highly scalable on DOD HPC resources.
This work demonstrates that the TIREM code is more than capable of performing at real-time rates. For the Test and Evaluation community, this technology enables the modeling of high-fidelity RF propagation operating in parallel with tactical network simulation software such as EMANE, NS-3, SNL, and other network modeling software.