Round Trip Time Values Research Articles

Performance Analysis and Prediction of 5G Round-Trip Time Based on the VMD-LSTM Method

With the increasing level of industrial informatization, massive industrial data require real-time and high-fidelity wireless transmission. Although some industrial wireless network protocols have been designed over the last few decades, most of them have limited coverage and narrow bandwidth. They cannot always ensure the certainty of information transmission, making it especially difficult to meet the requirements of low latency in industrial manufacturing fields. The 5G technology is characterized by a high transmission rate and low latency; therefore, it has good prospects in industrial applications. To apply 5G technology to factory environments with low latency requirements for data transmission, in this study, we analyze the statistical performance of the round-trip time (RTT) in a 5G-R15 communication system. The results indicate that the average value of 5G RTT is about 11 ms, which is less than the 25 ms of WIA-FA. We then consider 5G RTT data as a group of time series, utilizing the augmented Dickey–Fuller (ADF) test method to analyze the stability of the RTT data. We conclude that the RTT data are non-stationary. Therefore, firstly, the original 5G RTT series are subjected to first-order differencing to obtain differential sequences with stronger stationarity. Then, a time series analysis-based variational mode decomposition–long short-term memory (VMD-LSTM) method is proposed to separately predict each differential sequence. Finally, the predicted results are subjected to inverse difference to obtain the predicted value of 5G RTT, and a predictive error of 4.481% indicates that the method performs better than LSTM and other methods. The prediction results could be used to evaluate network performance based on business requirements, reduce the impact of instruction packet loss, and improve the robustness of control algorithms. The proposed early warning accuracy metrics for control issues can also be used to indicate when to retrain the model and to indicate the setting of the control cycle. The field of industrial control, especially in the manufacturing industry, which requires low latency, will benefit from this analysis. It should be noted that the above analysis and prediction methods are also applicable to the R16 and R17 versions.

QMon: A method to monitor queueing delay in OpenFlow networks

In software-defined networking (SDN), the decoupled architecture provides opportunities for efficiently measuring critical quality of service (QoS) parameters, such as delay. Existing approaches, to dynamically obtain delay, are based around calculating the transit time of a probe packet that travels through the data links. These approaches are not efficient as the probe packet injected into the data plane incurs considerable overhead. Additionally, a separate probe packet is required to measure the delay of each queue if more than one queue is present on the egress port of a switch. Thus, these approaches are not scalable. In this paper, we propose an efficient passive delay estimation method, queueing delay monitoring (qMon), to monitor queueing delay in SDN networks. qMon leverages the OpenFlow protocol to obtain queue statistics from switches at regular intervals, which are further employed to estimate the mean queueing delay for each interval. Thus, the proposed approach differs from the existing approaches as no packet is injected into the data plane to measure delay. The results show that for Poisson traffic and for bursty traffic with large ON intervals, round trip time (RTT) values estimated using qMon and ping utility demonstrate high correlation when the measured RTT value is considered as time-series data.

On the Modeling of RTT Time Series for Network Anomaly Detection

Network anomalies can seriously influence the performance of networks and cause huge financial losses. Existing studies modeled the round-trip time (RTT) time series of each link and identified their abnormal patterns independently to detect the network anomalies. However, they rarely investigated the correlation among links, and they rarely considered the goodness of fit and complexity in model selection, which led to low timeliness and accuracy of detection. They failed to understand the impact of network anomalies. In this work, we propose the RTS detection approach to address these challenges. Specifically, we, firstly, propose a link clustering method to cluster the links into different classes based on the topological location of pairwise links and the similarity between their RTT time series. Then, for each class of links, we consider the goodness of fit and complexity in model selection and select the suitable model to analyze their RTT time series. Finally, we propose a detection method to detect the network anomalies by observing the deviation between the probability density distribution of the current RTT values and the reference value. We perform experiments with data from public measurement infrastructures like RIPE Atlas to evaluate the performance of our approach. The results show that our approach can not only reduce the detection time and improve the accuracy of detection effectively but also can roughly evaluate the impact of network anomalies.

Enabling seamless communication over several IoT messaging protocols in OpenFlow network

The most prominent protocols for data transfer in internet of things (IoT) are message queuing telemetry transport (MQTT) and constrained application protocol (CoAP). The existing clients from both sides are unable to communicate directly because of the packet’s header structure difference in application and transport layer. In response, this paper aims to develop a bidirectional conversion server used to translate the specified messaging protocol interchangeably in the OpenFlow network and transmit the converted packet from both sides. The conversion server integrated the MQTT subscriber and CoAP POST object for converting the MQTT message into CoAP data. Similarly, the CoAP-MQTT translation was processed by CoAP GET and MQTT publisher object. The research was evaluated by analysing the round trip time (RTT) value, conversion delay, and power consumption. The RTT value for MQTT-CoAP required 0.5 s while the CoAP-MQTT was accumulated in 0.1 s for single-packet transmission. In addition, the SDN controller and the conversion server only consumed less than 1% central processing unit (CPU) usage during the experiment. The result indicated that the proposed conversion server could handle the translation even though there was an overwhelming request from the clients.

IoT Enabled Cluster Based Energy Aware Routing Protocol In WSN

Because of the unpredictable nature of sensor nodes, propagating sensory data raises significant research challenges in Wireless Sensor Networks (WSNs). Recently, different cluster-based solutions are designed to improve network stability and lifetime. However, most energy-efficient solutions are developed for homogeneous networks and uses only a distance parameter for data communication. Although, some existing solutions are attempted to improve the selection of next-hop based energy factor. Nevertheless, such solutions are unstable and lack reduce data delivery interruption in overloaded links. Our proposed solution aims to develop Reliable Cluster-based Energy-aware Routing (RCER) protocol for heterogeneous WSN which lengthens network lifetime and decreases routing cost. Our proposed RCER protocol makes use of heterogeneity nodes concerning their energy and comprises of two main phases; firstly, the network field is parted in geographical clusters to make the network more energy-efficient and secondly; RCER attempts optimum routing for improving the next-hop selection by considering residual-energy, hop-count and weighted value of Round-Trip Time (RTT) factors. Moreover, RCER restores routing paths and provides network reliability with improved data delivery performance. Simulation results demonstrate significant development of RCER protocol against their competing solutions.

Client-side rogue access-point detection using a simple walking strategy and round-trip time analysis

Traditional rogue access-point (AP) detection mechanisms are employed in network administration to protect network infrastructure and organization; however, these mechanisms do not protect end users from connecting to a rogue-AP. In this paper, a rogue-AP detection technique on the mobile-user side is proposed. By using a simple method involving walking, the round-trip time (RTT) and the modulation and coding scheme values are obtained, and a more accurate transmission rate for particular RTT values is thereby calculated. Further, the cleansed data are classified using the k-means method and the cumulative distribution function for the detection process. The results demonstrate that a rogue-AP can be detected with an F-measure value of up to 0.9. In the future, the proposed algorithm can be implemented as an application installed on mobile devices so that nontechnical users can detect rogue-APs.

NFV Provisioning in Large-Scale Distributed Networks With Minimum Delay

Network function virtualization (NFV) and software-defined networking (SDN) are two technologies that have emerged to reduce capital and operational costs, and to simplify network management. In this paper, we propose an SDN-based system that provisions virtual network functions (VNFs) to minimize round trip time (RTT) delay and synchronization delay requirements. Our system uses graphic-theoretic approaches to place newly requested VNFs including four centrality functions - betweenness, degree, closeness, and Katz. The system performance is evaluated using two random graph topologies representing the physical and logical structures. The impact of increasing the number of deployed VNFs is considered. The results indicate that the degree and Katz selection methods mostly provide the minimum RTT for physical networks, whereas the betweenness selection provides minimum RTT values for logical networks. Moreover, the closeness selection method provides the best synchronization delay for both logical and physical networks.

Performance evaluation of WebRTC-based online consultation platform

Information technologies give patients the opportunity to communicate with medical professionals remotely. Telemedicine uses these technologies to provide advanced healthcare and medical services. We present a medical online consultation application based on Web Real-Time Communications (WebRTC) technology enabling chat, audio, and video calls. Communication architecture and protocols of the application are explained in detail. Additionally, the user interface of the application is shown via performed calls. The application is tested and evaluated on different network connections (3G, 4G, local, and DSL) and different browsers and mobile operating systems (Android, Chrome, Firefox, Internet Explorer, iOS, Opera, Safari). During calls, communication quality parameters such as round-trip time (RTT) and packet loss, obtained via the WebRTC application programming interface, are analyzed. 3G, 4G, and local connections show low packet losses ($$1 %) in Android, Chrome, iOS, Opera, and Safari for DSL connection, but RTT values are low ($

RCER: Reliable Cluster-based Energy-aware Routing protocol for heterogeneous Wireless Sensor Networks.

Nowadays, because of the unpredictable nature of sensor nodes, propagating sensory data raises significant research challenges in Wireless Sensor Networks (WSNs). Recently, different cluster-based solutions are designed for the improvement of network stability and lifetime, however, most of the energy efficient solutions are developed for homogeneous networks, and use only a distance parameter for the data communication. Although, some existing solutions attempted to improve the selection of next-hop based on energy factor, nevertheless, such solutions are unstable and lack a reducing data delivery interruption in overloaded links. The aim of our proposed solution is to develop Reliable Cluster-based Energy-aware Routing (RCER) protocol for heterogeneous WSN, which lengthen network lifetime and decreases routing cost. Our proposed RCER protocol make use of heterogeneity nodes with respect to their energy and comprises of two main phases; firstly, the network field is parted in geographical clusters to make the network more energy-efficient and secondly; RCER attempts optimum routing for improving the next-hop selection by considering residual-energy, hop-count and weighted value of Round Trip Time (RTT) factors. Moreover, based on computing the measurement of wireless links and nodes status, RCER restore routing paths and provides network reliability with improved data delivery performance. Simulation results demonstrate significant development of RCER protocol against their competing solutions.

Deteksi dan Pencegahan Serangan Wormhole pada Protokol Routing AOMDV menggunakan Gabungan Metode Delphi dan RTT-TC pada Jaringan MANET

Mobile Ad Hoc Network (MANET) is a network consisting of a group of mobile nodes that don't have a fixed infrastructure. This causes the MANET to be vulnerable to attacks that can interfere with the process of communication and data transmission on the network. One type of attack that can attack the MANET is a wormhole attack. The wormhole is an attack on a network where there are two or more wormhole nodes that are interconnected and work together to attack network traffic or discard data packets it receives. Each wormhole node will be connected to each other using a wormhole link. To prevent wormhole attacks, the method that can be used is the Delay Per Hop Indicator (Delphi) method and the Round Trip Time and Topological Comparison (RTT-TC) method. The Delphi detects wormhole attacks by calculating the delay in each hop from the source node to the destination node. Whereas in the RTT-TC, wormhole attacks are detected by calculating the value of round trip time and topological comparison. The Delphi and RTT-TC methods have their advantages and disadvantages. In this study, it was proposed to combine the Delphi and RTT-TC methods to cover the disadvantage of each method.

Assessing the Limits of Mininet-Based Environments for Network Experimentation

Virtualization and emulation have become worthy approaches to save significant amounts of money related to physical resource acquisition expenditures. In light of this, the development of network emulation platforms has led a revolution in the research and testing of novel services and applications, as they provide a cost-effective, flexible and reproducible environment for experimentation. However, they present some practical issues, in particular, their scalability is one of the limiting factors as it links the emulated networks that can be successfully deployed on a given hardware. We address this matter by testing the consumption and exploitation of physical resources of one popular network emulation platform, Mininet. We follow a methodology based on the isolation of the threads associated to the operating system, the virtual hosts, and the monitoring tasks. In such a manner, this approach can measure the effect of the placement of threads in the available cores, and help optimize bottlenecks that jeopardize the results of network emulations. Additionally, we monitor several key performance indicators for general-purpose Mininet deployments in different network topologies, varying the number of active elements, links and network conditions such as packet loss or delay. Our results show that Mininet presents performance bounds in commodity servers that suffice a wide range of general network tests. It achieves aggregated bandwidths above 10 Gb/s and median roundtrip time values around 1 ms, even in demanding scenarios where more than a thousand hosts, up to 64-hop paths and 64

MDP-Based Model for Interest Scheduling in IoT-NDN Environment

Named data networking (NDN) is a novel paradigm that can acknowledge the unprecedented increase in the volume of global IoT traffic which initiates a new network forwarding plane. We propose and evaluate a Markov decision process (MDP)-based scheduler to forward diverse IoT Interests to fitting interfaces in an NDN router to fetch Data with less round trip time (RTT), to meet latency requisites. Simulation results of our MDP model show scheduling Interests to right interfaces reduce the RTT value by 25-30% than existing forwarding strategies. The delay is around 30 ms for higher density of traffic comparatively less than other existing work.

Adaptive RTO for handshaking-based MAC protocols in underwater acoustic networks

Underwater acoustic networks (UANs) are attracting interest in recent decades. The unique characteristics of the underwater acoustic channel, such as long propagation delay, delay variance, and high bit error rate, present challenges for the medium access control (MAC) protocol design in UANs. Most existing medium access control protocols ignore the delay variance which prevents the accurate estimation of round trip time (RTT). The expected RTT value can be used to compute the Retransmission Time-Out (RTO) or the waiting time in MAC. The estimation of RTT is also meaningful for Automatic Repeat re-Quest (ARQ) scheme because the system should ensure reliable data transmissions in the presence of high bit error rate in the underwater acoustic channel. By analyzing the impact of RTO on throughput under the effect of delay variance, we conclude that the fixed RTO is inefficient and RTO should be adaptively set to improve the throughput. We present a novel approach of predicting the RTT using a Bayesian dynamic linear model, and then adjust RTO adaptively according to the predicted values. Simulation results show that the predicted values can adapt quickly to the sample RTT values. Under the effect of RTT fluctuations, the Bayesian algorithm offers performance gains in terms of throughput and prediction performance, comparing with Karn’s algorithm. Our study highlights the value of predicting the RTT using Bayesian approach in underwater acoustic networks.

Reconciling the value of the elevator round trip time between calculation and simulation

This paper attempts to understand the reasons for the difference in the value of the round trip time between calculation and simulation. It is posited the main reason for the difference is the combination of two factors: the restricted car capacity and the randomness in the behavior of the elevator traffic system, thus leading to a reduced effective car loading (effectively based on a smaller number of passengers in the car). There are three sources of randomness in the behavior of the system: the randomness of the passenger destinations (thus making the value of the round trip time a random variable), the randomness of the passenger arrival (driven by a Poisson passenger arrival model), and the effect of elevator bunching (thus making the value of the interval a random variable). Using a MATLAB-based simulator, the value of the round trip time is plotted against the system loading level for the case of a single entrance and incoming traffic only. Different conditions are simulated, including constant and random passenger arrivals, as well as queues-allowed and queues-not-allowed conditions. Varying these conditions provides an essential insight into the variation of the round trip time and the reasons for it. The effect of the number of passengers boarding the elevator on the value of the round trip time (and thus on the value of the system handling capacity) is investigated in more detail.

Adaptive rate‐based congestion control with weighted fairness through multi‐loop gradient projection internal model controller

As a transmission control protocol (TCP) implementation imposes the sources with small round trip time (RTT) to allocate the bottleneck unfairly, an adaptive congestion control is necessary to avoid packet loss along with fairness. The main idea of this paper is to design an adaptive rate-based queue management scheme based on gradient projection method and internal model control for network sources with different RTT values. The goal is to achieve weighted fairness, maximum utilisation and compatibility with both large and small RTTs. The communication network consisting of a bottleneck link and N TCP sources is considered as a multi-input single-output system. In the proposed approach, the number of the active TCP sources is determined adaptively and the utilisation factors are updated. For this purpose, the gradient method is used to design the adaptation rule for the utilisation factors in order to obtain weighted fairness, and then the projection method is augmented with the gradient procedure to achieve maximum bottleneck utilisation. The proposed procedure can tolerate both large and small RTTs, and consequently, it can be used in a wide range of communication networks. Extensive simulations based on network simulator NS2 and Simulink validate the analytical results.

A robust and high-performance queue management controller for large round trip time networks

Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control–Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control–proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

Active Queue Management of TCP Flows with Self-scheduled Linear Parameter Varying Controllers

Control-theoretic approaches to Active Queue Management (AQM) are typically based on linearizations of fluid flow models around design conditions. These conditions depend on the Round Trip Time (RTT), and the AQM performance is known to degrade if RTT values during actual operation depart substantially from design values. To overcome this difficulty a self-scheduled LPV controller for AQM is considered in this paper, where the controller is modified in real-time based on RTT. Simulations show that the self-scheduled LPV controller has good performance for both constant and time-varying RTTs, and outperforms two other common control-theoretic approaches to AQM.

효율적인 네트워크 자원 관리를 위한 호스트의 접속 유형 판별에 관한 연구

최근 스마트 디바이스 사용이 대중화 되고 업무 환경 또한 PC중심에서 스마트 디바이스로 확대되어 가면서 무선트래픽 양이 급격하게 증가 되고 있다. Enterprise 네트워크 에서 무선 IP 대역과 무선 트래픽 대역폭 관리는 중요한 사항이 되고 있다. 네트워크 설계 시 단말 호스트들의 네트워크 접속 유형 판별은 효율적인 네트워크 설계와 관리에 큰 이점이 된다. 또한 판별된 단말 호스트의 지속적인 관리를 통해 효과적인 네트워크 운용이 가능하고, 접속 유형의 변화를 통해 NAT 사용 호스트를 판별 할 수 있다. 본 논문에서는 Enterprise 네트워크의 인터넷 접속점에서 수집된 트래픽의 RTT(Round-Trip-Time) 값을 이용하여 단말 호스트의 접속 유형을 판별하는 방법론을 제안한다. 또한, 실제 학내 망을 대상으로 제안하는 방법의 타당성을 증명한다. As the use of smart devices has become popular, the number of smart devices connected to network has increased and the amount of traffic from them has grown rapidly. The management of mobile traffic and IP address for smart devices in an enterprise network is crucial problem for efficient operation of network. The information about connection type of a terminal host to the network will be very useful for stable and efficient management of an enterprise network. Also, this information might be used to identify NAT device. In this paper, we propose a methodology to identify the connection type of a terminal host using RTT (Round-Trip-Time) value extracted from captured packets. We prove the feasibility of our proposed method in a target campus network.

Cross-layer reduction of wireless network card idle time to optimize energy consumption of pull thin client protocols

Thin client computing trades local processing for network bandwidth consumption by offloading application logic to remote servers. User input and display updates are exchanged between client and server through a thin client protocol. On wireless devices, the thin client protocol traffic can lead to a significantly higher power consumption of the radio interface. In this article, a cross-layer framework is presented that transitions the wireless network interface card (WNIC) to the energy-conserving sleep mode when no traffic from the server is expected. The approach is validated for different wireless channel conditions, such as path loss and available bandwidth, as well as for different network roundtrip time values. Using this cross-layer algorithm for sample scenario with a remote text editor, and through experiments based on actual user traces, a reduction of the WNIC energy consumption of up to 36.82% is obtained, without degrading the application's reactivity.

Delay Resistant Transport Protocol for Deep Space Communication

The throughput of conventional transport protocols suffers significant degradation with the increased Round Trip Time (RTT) typically seen in deep space communication. This paper proposes a Delay Resistant Transport Protocol (DR-TCP) for point-to-point communication in deep space exploration missions. The issues related to deep space communication protocol design and the areas where modifications are necessary are investigated, and a protocol is designed that can provide good throughput to the applications using a deep space link. The proposed protocol uses a cross layer based approach to find the allocated bandwidth and avoids initial bandwidth estimation. A novel timeout algorithm estimates the timeout duration with an objective to maximize throughput and avoid spurious timeout events. The protocol is evaluated through extensive simulations in ns2 considering high RTT values typically seen in Lunar and Mars Exploration Networks under different conditions of packet error rates. DR-TCP provides a significant increase in the throughput as compared to traditional transport protocols under the same conditions. A novel adaptive redundant retransmission algorithm is also presented to take care of the high PER in deep space links. The effect of the Retransmission Frequency has been critically analyzed considering both Lunar and Deep Space scenarios under different levels of PER. The results are very encouraging even in high error conditions. The protocol exhibits a RTT independent behavior in throughput, which is the most desirable quality of a protocol for deep space communication.