Performance evaluation of synchronous distributed wireless network emulator for high-speed mobility

Abstract

The IEEE 1588 Precision Time Protocol Version 2 (PTP v2) standard was developed to establish precise synchronization protocols for distributed nodes, and thus facilitate the development of distributed time-based systems. As an example of an applied system, we developed a distributed wireless network emulator that permits precise and stable synchronized time-based wireless link scheduling. In our system, each agent node simply emulates schedule-based wireless links without exchanging control messages with any other nodes. This emulator is designed to test IP-based protocols for high scalability and high-speed mobility while maintaining high accuracy levels over extended periods of time. In our previous work, we showed the existence of a relationship between packet handling size and accuracy in a developed emulator system. In this study, we evaluate the performance of agent node loads, and their relationship to processing time accuracy, by obtaining time information from PTP v2. These factors are important when deciding future extension policy. From our experimental results, we determined that performance has two kind of influence. Specifically, processing time increases as loading increases, and some processing elements become excessively long under high load conditions. These factors have a significant influence on time-based distributed systems, such as our distributed mobile network emulator, which is designed to handle processes at microsecond speeds.