Designed, developed, debugged, and tested C++ multithreaded backend Linux VOIP server software to allow PTT (Push To Talk) communications among mobile workers and dispatchers. Wrote gateways that use MOROTRBO XRTs to allow MOTOTRBO Connect Plus two-way radios to talk to WebRTC clients such as web browsers and PoC (PTT over Celluar) smartphone apps.Wrote software that converts AMBE+2 audio from Connect Plus radios to PCM audio and vice versa. Supported Connect Plus Enhanced Privacy encryption and decryption.Maintained software running on a Small Board Computer (SBC) that allowed almost any brand of LMR network to be included in PTT conversations using a simple highly compatible analog interface to a donor radio.Scaled backend server software to allow over a thousand clients to communicate with each other on a single c5.xlarge AWS EC2 instance. Made backed server VOIP software run in docker so that dozens of containers run on the same EC2 host in isolation of each other to improve reliability and ease of installations and upgrades.Maintained software for tracking locations of radios using MOTOTRBO Connect Plus XRC controllers.

The VOIP (Voice Over IP) software products at pdvWireless Inc were sold to TeamConnect LLC in January 2019, at which time I changed careers to TeamConnect. I developed mostly the same products at both companies except for one earlier pdvWireless product that allowed mobile workers with just a push-of-a-button to send an email with a Customized Subject Line to a busy dispatcher allowing the most time-sensitive call to be dealt with before the more routine calls. This meant no hold time, no missed calls, and immediate improvement in productivity. My role was adding support for mobile workers to use Sprint QChat PTT cell phones by developing a backend server running in a C++ multithreaded Linux application using SIP, RTP, and RTCP to communicate with Sprint's network.

Got up to speed quickly on large software such as the 1.5 million line Naval Simulation System (NSS).Wrote 5000 lines of GNU Makefiles with ability to build in parallel and saved a few man-hours per day.Wrote over 1,700 problem reports in 14 months for an Independent Verification and Validation of a competitor's C++ optimistic Parallel Discrete Event Simulation (PDES).Metron supported Air Force Course of Action (COA) simulations so well, the Air Force gave Metron more contracts worth $850,000. My role in our team was to create timely releases and provide technical support.Sped up MIT Lincoln Labs' Open Architecture Simulation Interface Specification (OASIS). MIT's version was too slow because it was sequential. I played a major role in the design and coding of a parallel version that used SPEEDES.Designed and coded a pilot project to automate the previously error-prone, manual, and time-consuming task of following difficult rules imposed by SPEEDES. When done, it will save Metron clients substantial time. It automatically changes a user's C++ simulation code using the ROSE compiler from Lawrence Livermore National Lab.Ported SPEEDES to many High Performance Computers (HPC): SGI, Sun, HP, etc.Designed, and implemented a robust and usable C++ API for automatically transferring complex data structures between computers in the simulation. The new API improved reliability and saved coding time by automatically serializing data and causing the compiler to flag misuses of the API.Designed and wrote many improvements to a C++ program called Fast Master Air Attack Planning (Fast MAAP). It used Mixed Integer Linear Programming (MILP) to determine which aircraft and missiles should strike which targets so as to assign the assets efficiently to maximize the number of targets struck.

Wrote about 350 test cases for a CAD tool that finds errors in Verilog HDL code.Wrote a script which partially automated this regression testing.

Used CAD program to draw construction plans for gas stations. Drawings were used by construction workers and to obtain government permits.