Delay Performance Analysis with Short Packets in Intelligent Machine Network
Wenyan Xu, Zhiqing Wei, Zhiqun Song, Yixin Zhang, Haotian Liu, Ying Zhou, Xiaoyu Yang, Yashan Pang
TL;DR
This work addresses delay performance in intelligent machine (IM) networks employing short packets under finite blocklength constraints. It builds a hybrid framework combining stochastic geometry (PPP-based network model) and queuing theory (M/G/1) to derive the transmission success probability $P_s$, the expected delay $T_m$, and the delay jitter $J_m$ for downlink transmission, incorporating finite-blocklength rate penalties $R_m \approx \frac{B_m}{N_m} \log_2(1+\gamma_m) - \sqrt{\frac{1}{2s}} Q^{-1}(\varepsilon) \log e$ and channel dispersion. The main contributions are analytic expressions for the three metrics under interference and density, plus Monte Carlo validation showing that increasing packet length $s$ or IM density $d_m$ worsens latency and that short packets improve performance, especially at high density. The results provide a theoretical basis for delay-aware optimization and design of IM networks with short packets.
Abstract
With the rapid development of delay-sensitive services happened in industrial manufacturing, Internet of Vehicles, and smart logistics, more stringent delay requirements are put forward for the intelligent machine (IM) network. Short packet transmissions are widely adopted to reduce delay in IM networks. However, the delay performance of an IM network has not been sufficiently analyzed. This paper applies queuing theory and stochastic geometry to construct network model and transmission model for downlink communication, respectively, proposes and derives the following three metrics, e.g., the transmission success probability (with delay as the threshold), expected delay, and delay jitter. To accurately characterize the transmission delay with short packets, the finite blocklength capacity is used to measure the channel transmission rate. Simulation results show that the increase of packet length and IM density significantly deteriorates the three metrics. Short packets are needed to improve the three metrics, especially in high IM density scenarios. The outcomes of this paper provide an important theoretical basis for the optimization design and performance improvement of IM networks.