One-way Delay Research Articles

Alarm: An Adaptive Routing Algorithm Based on One-Way Delay for Infiniband

Alarm: An Adaptive Routing Algorithm Based on One-Way Delay for Infiniband

A multipath scheduler based on cross-layer information for low-delay applications in 5G edge networks

Virtual Reality (VR) applications that require extremely low delay and high image quality are widely used in online games and other 5G scenarios, becoming a hot research field in recent years. However, the limited bandwidth in 5G edge networks fails to meet the peak rate requirements for multiple VR flows. MPTCP is suitable for 5G edge networks, supporting the simultaneous use of multiple networks on mobile devices. Nevertheless, accurately scheduling VR data blocks to different subflows to satisfy their low delay requirements is challenging due to their microburst characteristic. In this paper, we propose a novel MPTCP scheduler for cloud VR applications in 5G edge networks, called the Cross-layer information-based one-way delay Predictive Scheduler (CPS). CPS accurately predicts one-way delay by incorporating cross-layer information from both the application and edge wireless sides, and adaptively schedules VR data blocks to the optimal subflow. Experimental results show that CPS outperforms existing strategies, supporting 125% more users for VR applications in the typical scenario. CPS successfully meets the quality of experience needs of more users, providing a promising solution for large-scale deployment of cloud VR services in 5G edge networks.

A Round Trip Time Weighting Model for One-Way Delay Estimation

A Round Trip Time Weighting Model for One-Way Delay Estimation

Network Layer Privacy Protection Using Format-Preserving Encryption

Format-Preserving Encryption (FPE) algorithms are symmetric cryptographic algorithms that encrypt an arbitrary-length plaintext into a ciphertext of the same size. Standardisation bodies recognised the first FPE algorithms (FEA-1, FEA-2, FF1 and FF3-1) in the last decade, and they have not been used for network layer privacy protection so far. However, their ability to encrypt arbitrary-length plaintext makes them suitable for encrypting selected packet header fields and replacing their original value with ciphertext of the same size without storing excessive information on the network element. If the encrypted fields carry personally identifiable information, it is possible to protect the privacy of the endpoints in the communication. This paper presents our research on using FPE for network layer privacy protection and describes LISPP, a lightweight, stateless network layer privacy protection system. The system was developed for programmable smart network interface cards (NIC) and thoroughly tested in a real network environment. We have created several implementations ranging from pure P4 to a mix of P4 and C implementations, exploring their performance and the suitability of target-independent P4 language for such processor-intensive applications. Finally, LISPP achieved line rate TCP throughput, up to 4.5 million packets per second, with the penalty of only 30 to 60 microseconds of additional one-way delay, proving that it is adequate for use in production networks. The most efficient implementation was with the FF3-1 algorithm developed in C and carefully adapted to the specific hardware configuration of the NIC.

Prediction of evolution behavior of Internet bottleneck delay based on improved Logistic equation

As massive real-time systems and various types of networks connect to the Internet, real-time Internet connections are becoming increasingly prominent. Research on bottleneck delays provides a reference for solving real-time performance issues in data transmission for real-time systems on the Internet. In this study, under the Internet macro-topology, we utilized real probing data to conduct an in-depth study on the evolution behavior of bottleneck delays in end-to-end delays. We demonstrate that more than 90% of valid paths were 9 hops on average, and the ratio of the maximum link delay to the one-way delay was above 1/3. In addition, bottleneck delays on the valid paths were mainly concentrated in the range of [0, 130 ms], and the relative spatial positions of the bottleneck delays appearing in the links of one-way delays tended to be near the middle. The timing evolution sequence of the bottleneck delays exhibited a slow upward trend and quasiperiodic oscillations. On this basis, the Logistic equation was introduced to describe this evolution and establish the prediction model, and the gray Wolf Optimizer (GWO) algorithm was used to fit and optimize the model parameters. Finally, experiments were conducted to verify the validity and accuracy of the models. Their prediction accuracies exceeded 90% according to a quantitative evaluation, and the models fit well according to a χ2 goodness-of-fit test. This validates our modeling approach and demonstrates that the model can predict bottleneck delays accurately in a short period of time.

Performance of the modified clock skew estimator and its upper bound for the IEEE 1588v2 (PTP) case under packet loss and fractional Gaussian noise environment

Precision Time Protocol (PTP) is a time protocol based on the Master and Slave exchanging messages with time stamps. In practical PTP systems, we have packet loss, a phenomenon where some of the PTP messages get lost in the Network. Packet loss may reduce the performance of the clock skew estimator from the mean square error (MSE) perspective. Recently, the same authors presented simulation results that show the clock skew performance of the three clock skew estimators (the two-way delay (TWD) clock skew estimator and the one-way delay (OWD) clock skew estimator for the Forward and Reverse paths) under the packet loss case in the fractional Gaussian noise (fGn) environment with Hurst exponent parameter (H) in the range of 0.5 ≤ H < 1, where indeed the clock skew performance was degraded compared to the non-packet loss case. Please note that for 0.5 < H < 1, the corresponding fGn is of long-range dependency (LRD). This paper proposes an algorithm that estimates the missing timestamps in the packet loss and fGn (0.5 ≤ H < 1) case. We use those estimates to generate three modified clock skew estimators (the two-way delay (TWD) modified clock skew estimator and the one-way delay (OWD) modified clock skew estimator for the Forward and Reverse paths) applicable to the packet loss, non-packet loss, and fGn (0.5 ≤ H < 1) case based on the same authors’ previously developed clock skew estimators. Those modified clock skew estimators led, based on simulation results, to an improved clock skew performance in the packet loss and fGn (0.5 ≤ H < 1) case compared with the authors’ previously developed clock skew estimators and those known from the literature (the ML-like (MLLE) and Kalman clock skew estimators). With the MSE expression, the system designer can know how many Sync periods are needed for the clock skew synchronization task to reach the system’s requirements from the MSE perspective. But no MSE expression exists in the literature for the packet loss case. In this paper, we derive closed-form approximated expressions for the MSE upper bounds related to the modified TWD and OWD clock skew estimators valid for the packet loss and fGn (0.5 ≤ H < 1) cases.

A real-time hypertext transfer protocol intrusion detection system on web server

Behind the rapid development of the internet in today’s era, various types of crime are also targeting vital players in the internet industry. With many online crime types rampant, an antidote is also needed to suppress internet crime. Therefore, the researcher proposes a solution in the form of a Keris, namely the hypertext transfer protocol (HTTP) intrusion detection system (IDS) that runs on the server where our website is running. Keris works by detecting rampant intrusions that attack servers or websites. When an intrusion is detected, Keris will notify the system admin using the Keris Telegram chatbot or an alternative Keris mobile application with firebase cloud messaging (FCM) technology. The research was conducted by comparing the results of one-way delay (OWD) between Telegram Webhook and FCM with the help of the open web application security project (OWASP) zed attack proxy (ZAP) test tool. From the results of the tests, OWD against directory brute force attacks on Telegram Webhook for 0.72 seconds and on FCM for 0.44 seconds. In this case, FCM is more suitable for real-time notifications if we need a very responsive notification.

Asymmetry-Aware Load Balancing With Adaptive Switching Granularity in Data Center

Datacenter networks provide large bisection bandwidth by load balancing traffic over rich parallel paths in multi-rooted tree topologies. Nevertheless, production datacenters operate under various path diversities caused by traffic dynamics, hardware failures and heterogeneous switching equipment. Therefore, the load balancing schemes in data center should be resilient to network asymmetry. Prior fine-grained schemes such as RPS and Presto are prone to experience packet reordering problem under asymmetric topology since they split flows into small units which are spread across all parallel paths. The coarse-grained solutions such as ECMP and LetFlow effectively avoid packet reordering, but easily leading to under-utilization of multiple paths. To solve these problems, we propose a load balancing mechanism called AG, which adaptively adjusts switching granularity according to the asymmetric degree of multiple paths. AG increases switching granularity to alleviate packet reordering under large degrees of topology asymmetry, while reducing switching granularity to obtain high link utilization under small degrees of topology asymmetry. Moreover, we design a switch-based scheme which measures the difference of one-way delay of multiple paths to obtain accurate state of topology asymmetry with low overhead. AG is a practical switch-based solution without modification at end hosts. The experimental results of NS2 simulations and real implementation show that AG reduces the average and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$99^{th}$</tex-math> </inline-formula> flow completion time by up to 54% and 65% compared with the state-of-the-art load balancing schemes, respectively.

Small-Scale Demonstration of Remote Control of Patrol and Work Robot with Arms Employing Local 5G System

Local (private) 5G system can provide a secure and flexible network using the cellular-based technologies at their facilities (e.g., factories, agricultural lands, and buildings). We constructed a small-scale demonstration system that exhibits the remote control of a patrol and work robot with arms using a local 5G system. The constructed robot comprises a robot operating system-based unmanned ground vehicle, two laser range finders, a webcam, an omnidirectional camera, and a six-axis robot arm. To fabricate a demonstration system with open-source software, we assessed the one-way delay of video streaming by changing different CPU, camera types, drivers, applications, and video resolutions. According to the assessment findings, it was demonstrated that it is possible to realize approximately 100ms delay under the limited resolution condition, and the allowable maximum absolute delay of 300ms can be attained even for full HD (1920 × 1080) resolution of this demonstration. Furthermore, local 5G was demonstrated to reduce delay variations to the same level as wired systems. It was also clarified that the increase in delay due to the application of local 5G is relatively small (5-25% in total delay) in this demonstration. Finally, we employed the small-scale demonstration system for the online and onsite campus tours for high school students.

Wireless Network Security Using Load Balanced Mobile Sink Technique

Real-time applications based on Wireless Sensor Network (WSN) technologies are quickly increasing due to intelligent surroundings. Among the most significant resources in the WSN are battery power and security. Clustering strategies improve the power factor and secure the WSN environment. It takes more electricity to forward data in a WSN. Though numerous clustering methods have been developed to provide energy consumption, there is indeed a risk of unequal load balancing, resulting in a decrease in the network’s lifetime due to network inequalities and less security. These possibilities arise due to the cluster head’s limited life span. These cluster heads (CH) are in charge of all activities and control intra-cluster and inter-cluster interactions. The proposed method uses Lifetime centric load balancing mechanisms (LCLBM) and Cluster-based energy optimization using a mobile sink algorithm (CEOMS). LCLBM emphasizes the selection of CH, system architectures, and optimal distribution of CH. In addition, the LCLBM was added with an assistant cluster head (ACH) for load balancing. Power consumption, communications latency, the frequency of failing nodes, high security, and one-way delay are essential variables to consider while evaluating LCLBM. CEOMS will choose a cluster leader based on the influence of the following parameters on the energy balance of WSNs. According to simulated findings, the suggested LCLBM-CEOMS method increases cluster head selection self-adaptability, improves the network’s lifetime, decreases data latency, and balances network capacity.

A Novel Switching Algorithm to the Preferred Clock Skew Estimator Applicable for the PTP Case in the Fractional Gaussian Noise Environment

Recently, the same authors provided a switching algorithm for the preferred clock skew estimator appropriate for the precision time protocol (PTP) scenario. The algorithm chooses the one‐way delay (OWD) clock skew estimator for the Forward path or the Reverse path or the two‐way delay (TWD) clock skew estimator that has the best performance in the mean square error (MSE) perspective. However, the switching algorithm applies only to the Gaussian scenario. In a real system, the packet delay variation (PDV) can be characterized as an fractional Gaussian noise (fGn) process where the Hurst exponent parameter can also have values higher than 0.5. Thus, the Gaussian case‐switching algorithm may not apply in a real system where after a small set of PTP measurements, the switching algorithm should be able to switch effectively to the preferred clock skew estimator with the best performance in the MSE perspective. In this paper, the PDV is characterized as an fGn process where the Hurst exponent (H) is in the range of 0.5 ≤ H &lt; 1. We estimate the unknown PDV variances and the Hurst exponent parameters of the Forward and Reverse paths. These estimated parameters are used for switching to the preferred clock skew estimator from the MSE perspective, even in the presence of asymmetry in the PDV or in the Hurst exponent parameters. We also detect and alarm for the unexpected load, cyber‐attack, or clock skew deviation that can occur in a real system.

Assessing the Effects of Delay to NMP via Audio Analysis.

For network music performance (NMP), end-to-end delay is the most critical factor affecting the quality of experience (QoE) of the musicians, as longer delays prevent the musicians from synchronizing. To analyze the sensitivity of QoE to delay, we performed a controlled NMP experiment, where 11 pairs of musicians performed under a wide range of delays. The analysis of the QoE questionnaires answered by the participants produced results with wide variances, making the extraction of solid conclusions quite difficult. In this paper, we complement the subjective study with an analysis of the performance tempo of the NMP sessions. Specifically, we used signal processing techniques to analyze the audio recordings of the experiments, to recover the performance tempo of the musicians, assess its evolution during each session, and correlate it with the underlying delay. The results of the analysis indicate that musicians in real NMP settings are more tolerant to delay than previously thought, managing to reach and maintain a steady tempo even with one-way delays of 40 ms. We also study how the performance tempo is related to delay, finding that the exact relationship between the two depends on the musicians.

Concept and Architecture for Applying Continuous Machine Learning in Multi-Access Routing at Underground Mining Vehicles

Autonomous moving vehicles facilitate mining of ore in underground mines. The vehicles are usually equipped with many sensor-based devices (e.g., Lidar, video camera, proximity sensor, etc.), which enable environmental monitoring, and remote control of the vehicles at the control center. Transfer of sensor-based data from the vehicles towards the control center is challenging due to limited connectivity enabled by the multi-access technologies of the communication infrastructure (e.g., 5G, Wi-Fi) within the underground mine, and the mobility of the vehicles. This paper presents design, development, and evaluation of a concept and architecture enabling continuous machine learning (ML) for optimizing route selection of real-time streaming data in a real and emulated underground mining environment. Continuous ML refers to training and inference based on the most recently available data. Experiments in the emulator indicated that utilization of a ML-based model (based on the RandomForestRegressor) in decision making achieved ~5–13% lower one-way delay in streaming data transfers, when compared to a simpler heuristic model.

Helix Multi-layered: a context broker federation for an efficient cloud-to-things continuum

Next-generation networks offer a flexible virtualized infrastructure that aligns back-end platforms for the Internet of Things with the management and orchestration (MANO) platforms. Together, they can synchronously support and improve application performance while establishing a cloud-to-things continuum. This study examines the architecture of the Helix Multi-layered technology platform designed for the management and distributed processing of context information through horizontal and vertical data federation techniques through a multi-level approach. We set out the architecture of the Helix Multi-layered platform with regard to its internal components, operating modes, and steps of its integration process, together with the 5th Generation (5G) mobile network infrastructure mediated by the Novel Enablers for Cloud Slicing (NECOS), a Lightweight Slice-Defined Cloud (LSDC) platform. The integration of NECOS and Helix Multi-layered platforms is examined in a test laboratory. In the article, experiments are carried out to compare the internal processing time of Helix Broker with that of Orion Context Broker, FIWARE’s main context broker. An assessment is made of the performance of some operating modes with the aim of achieving low latency in communication between the devices located at the edge. The experiments showed One-Way-Delay (OWD) values close to those of the Ultra-Reliable Low Latency Communications (uRLLC) requirements that are expected in 5G mobile networks.

Passive delay measurement for fidelity monitoring of distributed network emulation

Emulation has become a popular approach for the validation and evaluation of network research. It provides researchers with a contained, customizable, and scalable testing environment, which can be easily packaged and published for potential readers to reproduce their results. However, as the network components are only virtual, emulation lacks the inherent realism of physical testbeds. In light of this, monitoring specific metrics of the emulated network has been proposed as a solution to mitigate to some degree inaccuracies caused by emulation. While this is not difficult to implement in a single-machine setting (e.g. with Mininet), monitoring is limited by the lack of time synchronization in scenarios where the emulation is distributed over multiple physical machines (e.g., Distrinet). In this paper we tackle the case of packet delay monitoring, to which we propose a methodology for passively measuring one-way delays with underlying assumptions about time synchronization, and round-trip delays otherwise. For an efficient implementation of our methodology, we propose an eBPF-based packet measurement tool that performs better than current packet sniffers under emulation-specific assumptions. We implement and evaluate our system in an open testbed and show that it can reach results within few microseconds of perfect accuracy and precision.

Two Novel One-Way Delay Clock Skew Estimators and Their Performances for the Fractional Gaussian Noise/Generalized Fractional Gaussian Noise Environment Applicable for the IEEE 1588v2 (PTP) Case

Papers in the literature dealing with the Ethernet network characterize packet delay variation (PDV) as a long-range dependence (LRD) process. The fractional Gaussian noise (fGn) or the generalized fractional Gaussian noise (gfGn) belong to the LRD process. The IEEE1588v2 is a two-way delay (TWD) protocol that uses the messages from the Forward (Master to Slave) and the Reverse (Slave to Master) paths. Suppose we have a significant difference between the PDV variances of the Forward and the Reverse paths. Thus, if we can use only the path with the lowest PDV variance (namely, only the one-way delay (OWD) technique), we might get a better clock skew performance from the mean square error (MSE) point of view compared with the traditional TWD method. This paper proposes two OWD clock skew estimators, one for the Forward path and one for the Reverse path applicable for the white-Gaussian, fGn and gfGn environment. Those OWD estimators do not depend on the unknown asymmetry between the fixed delays in the Forward and Reverse paths and nor on the clock offset between the Master and Slave. We also supply two closed-form approximated expressions for the MSE related to our new proposed OWD clock skew estimators. In addition, we supply some conditions, summarized in a table, guiding us whether we should use the OWD clock skew estimator for the Forward path or for the Reverse path, or just use the TWD algorithm. Simulation results confirm that our new proposed OWD clock skew estimators achieve better clock skew performances from the MSE point of view, compared with the TWD clock skew estimator recently proposed by the same authors and compared with two literature known OWD methods (the maximum likelihood and Kalman clock skew estimators).

Development of a Simulated Portable Mesh Network via ESP8266-Based Devices with Utility Application

Mesh network is very effective for node-to-node communications. In networks that require and demand devices for home monitoring and control, uncommon topology like Mesh is viewed to have a more effective advantage. However, when it comes to networks, Mesh Network is almost left untouched in most studies simply due to the existing network solutions such as WLAN or Bluetooth. The existence of low-powered WPAN devices fill the demand in integrating devices into mesh networks. However, constant configuration could be very complex and difficult for a mesh using existing WPAN devices since nodes constantly move in and out dynamically in the mesh network. This study focused on the development of a simulated mesh network through ESP8266 enabled devices to deliver a straightforward setup and portable connectivity. The study also developed a utility application that integrates an algorithm for node network operations, and a facility that keeps track of mesh network information including delays, node connections, and data transmission. Three(3) portable ESP8266 devices were used and configured in the study. The devices were integrated in a simulated mesh network and subjected to network processes including identity tagging, dynamic connection, routing, One-way Delay and Payload Size Tests. Results of One-Way Delay and Payload Size Tests indicate consistency of transmission and receiving of data of nodes connecting and disconnecting to the simulated network. This can be used as basis in extending further into more high-end nodes like handheld devices and even computers. Similarly, the utilization of dedicated algorithm for Mesh in this study proved that portability can be achieved to avoid loss of connection when nodes abruptly fail in the network.

Average Delay-based early Congestion Detection in Named Data of Health Things

The Internet of Health Things (IoHT) is receiving more attention from researchers because of its wide use in the healthcare field. IoHT refers to medical devices whose main purpose is to transmit health data in a secure and lossless manner between them and healthcare personnel. However, in a medical emergency, sensors transmit vital patient data simultaneously and frequently, increasing the risk of congestion and packet loss. This problem is highly undesirable in an IoHT system, leading to undesirable results. To address this issue, a new approach based on Named Data Networking (NDN) (which is considered as the most appropriate internet architecture for IoT systems) is proposed to control congestion in IoHT systems. The proposed approach, Average delay-based early congestion Detection (ADCD), detects and controls congestion at consumer nodes by calculating the average queuing delay based on the one-way delay similar to that proposed in Sync-TCP. Then according to the calculated value, ADCD divides the network into three states: no-congested state, less congested state, and heavily congested state. The adjustment of the congestion window size is done according to the state of the network. ADCD was implemented in ndnSIM and compared to the Interest Control Protocol ICP. The results show that ADCD maximizes bandwidth utilization compared to ICP and maintains a reasonable delay.

Lifetime centric load balancing mechanism in wireless sensor network based IoT environment

Wireless sensor network (WSN) is a vital form of the underlying technology of the internet of things (IoT); WSN comprises several energy-constrained sensor nodes to monitor various physical parameters. Moreover, due to the energy constraint, load balancing plays a vital role considering the wireless sensor network as battery power. Although several clustering algorithms have been proposed for providing energy efficiency, there are chances of uneven load balancing and this causes the reduction in network lifetime as there exists inequality within the network. These scenarios occur due to the short lifetime of the cluster head. These cluster head (CH) are prime responsible for all the activity as it is also responsible for intra-cluster and inter-cluster communications. In this research work, a mechanism named lifetime centric load balancing mechanism (LCLBM) is developed that focuses on CH-selection, network design, and optimal CH distribution. Furthermore, under LCLBM, assistant cluster head (ACH) for balancing the load is developed. LCLBM is evaluated by considering the important metrics, such as energy consumption, communication overhead, number of failed nodes, and one-way delay. Further, evaluation is carried out by comparing with ES-Leach method, through the comparative analysis it is observed that the proposed model outperforms the existing model.

Optimization of the AODV-Based Packet Forwarding Mechanism for BLE Mesh Networks

The standard Bluetooth Low-Energy mesh networks assume the use of flooding for multihop communications. The flooding approach causes network overheads and delays due to continuous message broadcasting in the absence of a routing mechanism. Among the routing protocols, AODV is one of the most popular and robust routing protocol for wireless ad hoc networks. In this paper, we optimized the AODV protocol for Bluetooth Low-Energy communication to make it more efficient in comparison to the mesh protocol. With the proposed protocol (Optimized AODV (O-AODV)), we were able to achieve lower overheads, end-to-end delay, and average per-hop one-way delay in comparison to the BLE mesh (flooding) protocol and AODV protocol for all three scenarios (linear topology with ten nodes, multipath topology with six and ten nodes). In addition, the proposed protocol exhibited practically constant route requests and route reply setup times. Furthermore, the proposed protocol demonstrated a better Packet Delivery Ratio (PDR) for O-AODV (84%) in comparison to AODV (71%), but lower than the PDR of the mesh (flooding) protocol with 93%.