1. There have been major increases in hardware/software technology since the original system design.
2. Use of proprietary hardware/software is discouraged due to potential for obsolescence, single-source support. Commercial products exist that will satisfy most, if not all, requirements.
3. Processing demands at NAVSTAR Monitor Stations is fairly low (receive SV signals, time-tag & record signals, pre-processing, forward signals/results to MCS); real-time operating systems may not be needed.
4. Use of COTS hardware/software and standard APIs, RPCs recommended for longevity, maintainability.
5. Security of systems is imperative, but a protected facility can be assumed.
6. Systems must be of high reliability.