Goodput Ratio Research Articles

Learning-Based Transmission Protocol Customization for VoD Streaming in Cybertwin-Enabled Next-Generation Core Networks

Next-generation core networks are expected to achieve service-oriented traffic management for diversified Quality-of-Service (QoS) provisioning based on software-defined networking (SDN) and network function virtualization (NFV). In this article, a learning-based transmission protocol customized for Video-on-Demand (VoD) streaming services is proposed for a Cybertwin-enabled next-generation core network, which provides caching-based congestion control and throughput enhancement functionalities at the edge of the core network based on traffic prediction. The per-slot traffic load of a VoD streaming service at an ingress edge node is predicted based on the autoregressive integrated moving average (ARIMA) model. To balance the tradeoff between network congestion and throughput enhancement, a multiarmed bandit (MAB) problem is formulated to maximize the expected overall network performance in a long run, by capturing the relationship between transmission control actions and QoS provisioning. A comprehensive transmission protocol operation framework is also presented with in-network congestion control and throughput enhancement modules. Simulation results are presented to validate the efficacy of the proposed protocol in terms of packet delay, goodput ratio, throughput, and resource utilization.

A Multi-Custodians Distributed Storage Mechanism for DTN Storage-based Congestion Problem

Nowadays, distributed storage is adopted to alleviate Delay-tolerant networking (DTN) congestion, but reliability transmission during the congestion period remains an issue. In this paper, we propose a multi-custodians distributed storage (MCDS) framework that includes a set of algorithms to determine when should appropriate bundles be migrated (or retrieved) to (or from) the suitable custodians, so that we can solve DTN congestion and improve reliability transmission simultaneously. MCDS adopts multiple custodians to temporarily store the duplications of migrated bundle for releasing DTN congestion. Thus, MCDS has more opportunities to retrieve the migrated bundles when network congestion is mitigated. Two performance metrics are used to evaluate the simulation results: the goodput ratio (GR) that represents QoS of data transmission, and the retrieved loss ratio (RLR) that reflects the performance of reliability transmission. We also use another distributed storage mechanism based on single-custodian distributed storage (SCDS) to evaluate MCDS. Simulation results show that MCDS has better GR and RLR in almost all simulation cases. For various scenarios, the GR and RLR of MCDS are in the range of 10.6%-18.4% and 23.2%-36.8%, respectively, which are higher than those of SCDS.

A cross-layer design and ant-colony optimization based load-balancing routing protocol for ad-hoc networks

In order to periodically reassess the status of the alternate path route (APR) set and to improve the efficiency of alternate path construction existing in most current alternate path routing protocols, we present a cross-layer design and ant-colony optimization based load-balancing routing protocol for ad-hoc networks (CALRA) in this paper. In CALRA, the APR set maintained in nodes is aged and reassessed by the inherent mechanism of pheromone evaporation of ant-colony optimization algorithm, and load balance of network is achieved by ant-colony optimization combining with cross-layer synthetic optimization. The efficiency of APR set construction is improved by bidirectional and hop-by-hop routing update during routing discovery and routing maintenance process. Moreover, ants in CALRA deposit simulated pheromones as a function of multiple parameters corresponding to the information collected by each layer of each node visited, such as the distance from their source node, the congestion degree of the visited nodes, the current pheromones the nodes possess, the velocity of the nodes, and so on, and provide the information to the visiting nodes to update their pheromone tables by endowing the different parameters corresponding to different information and different weight values, which provides a new method to improve the congestion problem, the shortcut problem, the convergence rate and the heavy overheads commonly existed in existing ant-based routing protocols for ad-hoc networks. The performance of the algorithm is measured by the packet delivery rate, good-put ratio (routing overhead), and end-to-end delay. Simulation results show that CALRA performs well in decreasing the route overheads, balancing traffic load, as well as increasing the packet delivery rate, etc.

A discrete-time queueing model of EMD policy in high-speed networks

In this paper, we consider a discrete-time queue for the Early Message Discarding (EMD) policy in high-speed networks under bursty arrival. This system is analyzed as a quasi-birth-and-death (QBD) process. We derive the steady-state probability distribution of buffer content by using generating-functions approach. Finally, we obtain the useful performance measure— goodput ratio and give some numerical results.

Queueing and Fluid Analysis of Partial Message Discarding Policy

We consider a stream of packets that arrive at a queue with a finite buffer. A group of consecutive packets constitutes a frame. We assume that when an arriving packet finds the queue full, not only is the packet lost but also the future packets that belong to the same frame will be rejected. The first part of the paper deals with a detailed packet level queueing model; we obtain exact expressions for the stationary queue length distribution and the goodput ratio (i.e. the fraction of arriving frames that experience no losses). The second part deals with a fluid model and the fluid analysis leads to simple closed form expressions for the stationary workload process and the fluid goodput ratio.