The long-tailed distribution characterizes many properties of Internet traffic. The property is often modeled by Lognormal distribution, Weibull or Pareto distribution theoretically. However, it hinders us in traffic analysis and evaluation studies directly from these models due to their complex representations and theoretical properties. This paper proposes a Hyper-Erlang Model (Mixed Erlang distribution) for such long-tailed network traffic approximation. It fits network traffic with long-tailed characteristic into a mixed Erlang distribution directly to facilitate our further analysis. Compared with the well-known hyperexponential based method, the mixed Erlang model is more accurate in fitting the tail behavior and also computationally efficient.

The highly topological dynamics characterizes the most fundamental property of satellite networks with respect to terrestrial ones. The manifest feature directs the researches on various aspects of satellite networks, including protocol architecture investigations, routing protocol and reliable transmission control protocol design and enhancement, etc. This paper systematically quantifies the dynamical activities of regular low earth orbit (LEO) satellite network topologies. The number and length of network snapshots are formulated concisely. With this work, it compensates for the simplified topological assumptions in many LEO satellite network related researches. The thorough understanding of this basic feature not only provides for an accurate quantification of network behavior for researchers on satellite network community, but also could act as a guidance for future satellite constellation design and optimization.

The end-to-end delay of Internet is a fundamental indicator for network performance evaluation and has been becoming a hot issue in network measurements in recent years. There are two kinds of metrics related to the end-to-end latency, i.e., Round Trip Delay and One-way Delay metric. In the paper, we survey the recent progresses on these two types of metrics measurement. Special concerns are on the clock synchronization issue in one-way delay measurement. The problems in deploying end-to-end delay measurement and the timestamping issue are also summarized. The potential new research directions in delay measurement and analysis are discussed.

Collecting network traffic is becoming a more challenging task in passive network measurement due to the rapid growth of link speed. Flow-based network traffic capture and storage provides an efficient way for high-speed network measurement. The paper concentrates on the flow detection issue which is also the premise for further flow-based traffic analysis and modeling in such challenging environment. Based on the statistical investigation of the correlations between flow size and the maximum packet interarrival time within a flow, we obtain the empirical conditional distribution functions for some popular TCP protocol-based application flows, and then propose a Probability-Guaranteed Adaptive Timeout algorithm (PGAT) for flow termination decision. The assessment criteria for flow termination decision algorithm is systematically developed. Comparisons on flow generation ratio, flow intact ratio, and mean flow extra retaining time metrics indicate that the PGAT algorithm can obtain more attractive performance than other related works.

对低轨道（LEO）、walker星座类型的卫星网络拓扑结构动态变化特征进行量化，给出了精确计算系统周期内网络时司片数量和时司片长度的公式。通过研究，一方面弥补了卫星网络研究中对拓扑结构时司片特征的简单假设，另一方面也为未来卫星网络星座的设计提供一定的指导。