DCM: Delay as Component Model based on Hidden Striping Structure in Mobile Networks

Understanding communication delay in mobile networks is becoming more important as delay-sensitive scenarios become more prevalent. Round-trip time measurement, the conventional technique to measure communication delay, e.g., ping, outputs network-induced delay for each packet but is insufficient in identifying specific delay factors. We propose a model called Delay Component Model (DCM) to aid in clearly visualizing communication delay. We construct the DCM on the basis of our measurement study on packet-receipt intervals with packet transmission at a constant interval via commercial mobile networks in Japan. We find that the measured receipt-time intervals form striped patterns due to the combination of two components: a constant scheduler (ConstSched) and probability scheduler (ProbSched). We use the principle of forming striped patterns and develop a method of estimating the DCM structure. Finally, we evaluate our method by analyzing delay patterns measured in Long Term Evolution (LTE) and fifth-generation mobile (5G) networks. The results indicate that delay patterns in these networks are due to the combination of three components, i.e., a ConstSched with 20-ms intervals, ProbSched with 8-ms delay for LTE and 6-ms delay for 5G, and ProbSched with 1-ms delay.