Proactive Obsolete Packet Management Based Analysis of Age of Information for LCFS Heterogeneous Queueing System

This paper analyzes the Age of Information (AoI), focusing on transmitting status updates from source to destination. We analyze the Age of Information in a system comprised of two heterogeneous servers with exponential distribution parameters $\mu _{1}$ and $\mu _{2}$, respectively. Our study adopts the stochastic hybrid systems (SHS) methodology to thoroughly assess the system’s performance. We explore various queueing disciplines, including Last-Come-First-Serve (LCFS) with work-conservative and LCFS with probabilistic routing, to accurately quantify AoI and Peak AoI (PAoI) metrics. We have used the Proactive Obsolete Packet Management (POPMAN) approach to identify and discard obsolete packets proactively, thus enhancing server processing efficiency and ensuring orderly packet reception. We also investigate the following parameters, such as the probability of preemption of packets, the probability of packets getting obsolete, the probability of informative packets, and optimal splitting probabilities. Results show an improvement in both AoI and PAoI within the LCFS with work-conservative queueing system with the integration of the POPMAN method. Furthermore, LCFS with probabilistic routing using the POPMAN approach performs similarly to conventional methods. In all the queueing systems studied, as the arrival rate $\lambda \to \infty$, the average AoI and PAoI approach $1/(\mu _{1}+\mu _{2})$. For c servers, they approach $1/(\mu _{1}+\mu _{2}+\cdots +\mu _{c})$.