Internet Latency Research Articles

Making touch visible with the suture of fantasy with virtual aesthetician in “The Best Facial Clinic” – The glitchy-score of tele-synaesthesia performance in the age of global pandemic

In the wake of the COVID-19 pandemic, we have been adapting as fugitives of this accidental encounter with an “untouchable” virus, while being rendered into the shared virtual arena, where our discursive bodies are situated within, embedded in and tele-commuted to. Our increasing dependence on online interaction and video conferencing during the pandemic is not only facilitating social connectedness, but also contemplating the question: How to elongate our somatosensation and echo the embodied experience of touching through the incorporeal virtual connectivity? This essay focuses on the embodied nature of tele-synaesthesia performance, its potential effect of forging a rhythmic connection from one sensuous modality to another, and the concurrent emergences of glitch and internet latency as non-verbal cues of internet-situated communication. In reference to Laura Mark’s theory of haptic visuality, where vision triggers a tactile experience in the body; Naomi Bennett’s concept of virtual touch, in which an affective sensory response of touch can be elicited through non-tactile senses, Paul Sermon’s artistic production of Telematic Quarantine (2020) and Pandemic Encounter (2020), that telepresents the stories of self (isolation), and in relation to Michel Foucault’s concept Heterotopia in the context of internet-situated performance, I examine the performance work I have been developing during lockdown since March 2020: The Best Facial (2021), supported by Centre for Digital Media Cultures Research and School of Art Postgraduate Research at University of Brighton, a number of sessions of 25-minute 1-to-1 participatory tele-synaesthesia performances that take place on Zoom, where I become a virtual aesthetician and use telepresence to perform meditative virtual facial tactics, and to make tele-contact improvisation upon the surface of the participant’s face to trigger tactile experiences through haptic visuality, virtual touching, and auditory fantasization.

Design of robust power system for frequency control in industrial sectors for enhancing science education

The technique of remote monitoring of different gadgets and machinery in process plants businesses is catching on in the decades to come. Constant progress has been made in industrial automation development thanks to remote monitoring and diagnosis, which is done almost entirely through computers and the Internet. - A conventionally used SCADA system in the electricity system uses voltage and frequency as their primary system monitoring parameters, which are checked consecutively at regular intervals. It is feasible to reduce the observed voltage and frequency data to a single string that is then sent to monitoring/control room, where it may be compressed using appropriate data compression methods. To extract the required data from the sent string, use the appropriate decompression method at the receiving end. In order to allow a compressed string to be decoded into the input voltage and frequency, a MATLAB-based system was created that can generate this compressed string and output the voltage and frequency corresponding to the input. Aspects that have emerged as critical design issues in the development of a supervisory control system that is internet-based include latency (delays on the internet), the security of the system, and the design of the interface. In this project, the designers of supervisory control systems, namely, internet latency and security, faced all of the many design problems found on the Internet. The key objective of this system is to provide automated real-time XML report creation for the online and offline processes. Programmable Logic Controllers (PLCs), Supervisory control and data acquisition (SCADA), and virtual private networks (VPN) all play a part in making automation Internet-based. The software was built utilizing SCADA (Supervisory Control and Data Acquisition) software, PLC (Programmable Logic Controller) applications for controlling the real-time process, and VBA/front page scripts for managing information systems. Utilizing XML encoding and solely using VPN through GSM connection for communication between the server and client, the individual monitoring device may further enhance the system's security.

The New TCP Modules on the Block: A Performance Evaluation of TCP Pacing and TCP Small Queues

Google and the Bufferbloat community have designed several solutions to reduce Internet latency in recent years, involving different TCP-IP stack layers. One of these solutions is named TCP Small Queues (TSQ) and reduces a TCP flow latency by controlling the number of packets that each TCP socket can enqueue in the sender node. It works in conjunction with TCP Pacing (TP), which affects the actual TSQ size as a function of the TCP rate. This paper analyzes TSQ and TP’s performance through real-system tests over different networks’ bottlenecks, emphasizing Wi-Fi technologies, where their behavior strongly affects the Wi-Fi frame aggregation mechanism.

Impact of the COVID-19 pandemic on the Internet latency: A large-scale study

The COVID-19 pandemic dramatically changed the way of living of billions of people in a very short time frame. In this paper, we evaluate the impact on the Internet latency caused by the increased amount of human activities that are carried out on-line. The study focuses on Italy, which experienced significant restrictions imposed by local authorities, but results about Spain, France, Germany, Sweden, and the whole of Europe are also included. The analysis of a large set of measurements shows that the impact on the network can be significant, especially in terms of increased variability of latency. In Italy we observed that the standard deviation of the average additional delay – the additional time with respect to the minimum delay of the paths in the region – during lockdown is ∼3−4 times as much as the value before the pandemic. Similarly, in Italy, packet loss is ∼2−3 times as much as before the pandemic. The impact is not negligible also for the other countries and for the whole of Europe, but with different levels and distinct patterns.

Development of a telepresence robot with adaptive shared controller

ABSTRACTThis study presents the design and control of a telepresence robot based on an omnidirectional mobile platform. A personal computer is used as a user interface for communication via internet to a laptop computer placed on the mobile platform. The laptop computer receives user’s commands to control the mobile robot. Collisions of robot with obstacle can still occur during remote controlling because of the limitation of a fixed camera on the robot and/or internet latency. We first use an artificial potential field to prevent these collisions, and then design an adaptive shared controller (ASC) to improve the performance. This ASC method modulates the weights of human control and assistance control online not only according to environmental factors, but also based on the user’s control performance. Meanwhile, we use the iterated closest point (ICP) algorithm to build a map for providing user functional reference. The experimental results show that ASC is efficient in both obstacle avoidance and user workload reduction.

Reducing Latency in Virtual Machines: Enabling Tactile Internet for Human-Machine Co-Working

Software-defined networking (SDN) and network function virtualization (NFV) processed in multi-access edge computing (MEC) cloud systems have been proposed as critical paradigms for achieving the low latency requirements of the tactile Internet. While virtual network functions (VNFs) allow greater flexibility compared to hardware-based solutions, the VNF abstraction also introduces additional packet processing delays. In this paper, we investigate the practical feasibility of NFV with respect to the tactile Internet latency requirements. We develop, implement, and evaluate Chain-based Low latency VNF ImplemeNtation (CALVIN), a low-latency management framework for distributed Service Function Chains (SFCs). CALVIN classifies VNFs into elementary, basic, and advanced VNFs; moreover, CALVIN implements elementary and basic VNFs in the kernel space, while the advanced VNFs are implemented in the user space. Throughout, CALVIN employs a distributed mapping with one VNF per Virtual Machine (VM) in a MEC system. Furthermore, CALVIN avoids the metadata structure processing and batch processing of packets in the conventional Linux networking stack so as to achieve short per-packet latencies. Our rigorous measurements on off-the-shelf conventional networking and computing hardware demonstrate that CALVIN achieves round-trip times from a MEC ingress point via two elementary forwarding VNFs (one in kernel space and one in user space) and a MEC server to a MEC egress point on the order of 0.32 ms. Our measurements also indicate that MEC network coding and encryption are feasible for small 256 byte packets with an MEC latency budget of 0.35 ms; whereas, large 1400 byte packets can complete the network coding, but not the encryption within the 0.35 ms.

Teleoperated, In Situ Repair of an Aeroengine: Overcoming the Internet Latency Hurdle

There is a substantial financial incentive for in situ repair of industrial assets. However, the need for highly trained mechanics to travel to the location of a repair often results in inconveniently long downtimes. The emergence of robots capable of replicating human interventions on industrial equipment can be coupled with remote-control strategies to reduce the response time from several days to a few hours.

The Server Allocation Problem for Session-Based Multiplayer Cloud Gaming

Advances in cloud computing and GPU virtualization are allowing the game industry to move into a cloud gaming era. In this paper, we consider multiplayer cloud gaming (MCG), which is the natural integration of multiplayer online gaming and cloud gaming paradigms. With MCG, a game server and a set of rendering servers for the players need to be located and launched in the clouds for each game session. We formulate an MCG server allocation problem with the objective of minimizing the total server rental and bandwidth cost charged by the cloud to support an MCG session. The MCG server allocation problem is hard to solve optimally. We propose several efficient heuristics to address the problem and carry out theoretical analysis for the proposed hill-climbing algorithm. We conduct extensive experiments using real Internet latency and cloud pricing datasets to evaluate the effectiveness of our proposed algorithms as well as several alternatives. Experimental results show that our best algorithm can achieve near-optimal cost under real-time latency constraints.

MobisenseCar: A Mobile Crowd-Based Architecture for Data Acquisition and Processing in Vehicle-Based Sensing

The use of wireless technology via smartphone allows designing smartphone applications based on OBD-II for increasing environment sensing. However, uploading of vehicle’s diagnostics data via car driver’s tethered smart phone attests a long Internet latency when a large number of concurrent users use the remote mobile crowdsensing server application simultaneously, which increases the communication cost. The large volume of data would also challenge the traditional data processing framework. This paper studies design functionalities of mobile crowdsensing architecture applied to vehicle-based sensing for handling a huge amount of sensor data collected by those vehicle-based sensors equipped with a smart device connected to the OBD-II interface. The proposed MobiSenseCar uses Node.js, a web server architecture based on single-thread event loop approach and Apache Hive platform responsible for analyzing vehicle’s engine data. The Node.JS is 40% faster than the traditional web server side features thread-based approach. Experiment results show that MapReduce algorithm is highly scalable and optimized for distributed computing. With this mobile crowdsensing architecture it was possible to monitor information of car’s diagnostic system condition in real time, improving driving ability and protect the environment by reducing vehicle emissions.

Performance Evaluation of Node.js for Web Service Gateway in IoT Remote Monitoring Applications

The growth of mobile devices in Internet of Things (IoT) leads to a number of remote and controlling system related IoT applications. For instance, home automation controlling system uses client system such web apps on smartphone or web service to access the home server by sending control commands. The home server receives the command, then controls for instance the light system. The web service gateway responsible for handling clients’ requests attests an internet latency when an increasing number of end users requests submit toward it. Therefore, this web service gateway fails to detect several commands, slows down predefined actions which should be performed without human intervention. In this paper, we investigate the performance of a web server-side platgorm based event-driven, non-blocking approach called Node.js against traditional thread-based server side approach to handle a large number of client requests simultaneously for remote and controlling system in IoT remote monitoring applications. The Node.JS is 40% faster than the traditional web server side features thread-based approach. The use of Node.js server-side handles a large number of clients’ requests, then therefore, reduces delay in performing predefined actions automatically in IoT environment.

Reducing Internet Latency: A Survey of Techniques and Their Merits

Latency is increasingly becoming a performance bottleneck for Internet Protocol (IP) networks, but historically, networks have been designed with aims of maximizing throughput and utilization. This paper offers a broad survey of techniques aimed at tackling latency in the literature up to August 2014, as well as their merits. A goal of this work is to be able to quantify and compare the merits of the different Internet latency reducing techniques, contrasting their gains in delay reduction versus the pain required to implement and deploy them. We found that classifying techniques according to the sources of delay they alleviate provided the best insight into the following issues: 1) The structural arrangement of a network, such as placement of servers and suboptimal routes, can contribute significantly to latency; 2) each interaction between communicating endpoints adds a Round Trip Time (RTT) to latency, particularly significant for short flows; 3) in addition to base propagation delay, several sources of delay accumulate along transmission paths, today intermittently dominated by queuing delays; 4) it takes time to sense and use available capacity, with overuse inflicting latency on other flows sharing the capacity; and 5) within end systems, delay sources include operating system buffering, head-of-line blocking, and hardware interaction. No single source of delay dominates in all cases, and many of these sources are spasmodic and highly variable. Solutions addressing these sources often both reduce the overall latency and make it more predictable.

Analysis of Minimum Interaction Time for Continuous Distributed Interactive Computing

Distributed interactive computing allows participants at different locations to interact with each other in real time. In this paper, we study the interaction times of continuous Distributed Interactive Applications (DIAs) in which the application states change due to not only user-initiated operations but also time passing. Given the clients and servers of a continuous DIA, its interaction time is directly affected by how the clients are assigned to the servers as well as the simulation time settings of the servers. We formulate the Minimum Interaction Time (MIT) problem as a combinatorial problem of these two tuning knobs and prove that it is NP-hard. We then approximate the problem by fixing the client assignment or the simulation time offsets among the servers. When the client assignment is fixed, we show that finding the minimum achievable interaction time can be reduced to a weighted bipartite matching problem. We further show that this approach establishes a tight approximation factor of 3 to the MIT problem if each client is assigned to its nearest server. When the simulation time offsets among the servers are fixed, we show that finding the minimum achievable interaction time is still NP-hard. This approach can approximate the MIT problem by a factor within 2 if the simulation times of all servers are synchronized. A mix of the above two approaches better approximates the MIT problem within a factor of 5/3. We further conduct experimental evaluation of these approaches with three real Internet latency datasets.

Analysis of Server Provisioning for Distributed Interactive Applications

Increasing geographical spreads of modern distributed interactive applications (DIAs) make distributed server deployment vital for combating network latency and improving the interactivity among participants. In this paper, we investigate the server provisioning problem that concerns where to place servers for DIAs. We formulate the server provisioning problem with an objective of reducing the network latency involved in the interaction between participants. We prove that the problem is NP-hard under several scenarios. We analyze the performance of the classical $k$ -median server placement for DIAs and propose a new greedy server provisioning heuristic for DIAs. Theoretical analysis shows that the approximation ratio of the proposed greedy algorithm is much lower than that of the $k$ -median placement. Experiments using real Internet latency data also show that our proposed algorithm significantly outperforms the $k$ -median and other baseline server placements.

Workshop report

This paper reports on a workshop convened to develop an action plan to reduce Internet latency. Internet latency has become a focus of attention at the leading edge of the industry as the desire to make Internet applications more responsive outgrows the ability of increased bandwidth to address this problem. There are fundamental limits to the extent to which latency can be reduced, but there is considerable capacity for improvement throughout the system, making Internet latency a multifaceted challenge. Perhaps the greatest challenge of all is to re-educate the mainstream of the industry to understand that bandwidth is not the panacea, and other optimizations, such as reducing packet loss, are at odds with latency reduction. For Internet applications, reducing the latency impact of sharing the communications medium with other users and applications is key. Current Internet network devices were often designed with a belief that additional buffering would reduce packet loss. In practice, this additional buffering leads to intermittently excessive latency and even greater packet loss under saturating load. For this reason, getting smarter queue management techniques more widely deployed is a high priority. We can reduce these intermittent increases in delay, sometimes by up to two orders of magnitude, by shifting the focus from packet loss avoidance to delay avoidance using technology that we already have developed, tested, implemented and deployed today. There is also plenty of scope for removing other major sources of delay. For instance, connecting to a website could be completed in one roundtrip (the time it takes for packets to travel from source to destination and back again) rather than three or four, by folding two or three rounds of flow and security set-up into the first data exchange, without compromising security or efficiency. Motivating the industry to deploy these advances needs to be aided by the availability of mass-market latency testing tools that could give consumers the information they need to gravitate towards low latency services, providers and products. There is no single network latency metric but several alternatives have been identified that compactly express aggregate delay (e.g. as relationships or a constellation), and tools that make use of these will give greater insight into the impact of changes and the diversity of Internet connections around the world. In many developing countries (and in rural regions of developed countries), aside from Internet access itself, there are significant structural issues, such as trombone routes through the developed world and a lack of content distribution networks (CDNs), that need to be addressed with more urgency than Active Queue Management (AQM) deployment, but the `blank slate' of new deployments provides an opportunity to consider latency now. More widespread use of Internet exchange points for hosting local content and fostering local interconnections is key to addressing some of these structural challenges.

The Client Assignment Problem for Continuous Distributed Interactive Applications: Analysis, Algorithms, and Evaluation

Interactivity is a primary performance measure for distributed interactive applications (DIAs) that enable participants at different locations to interact with each other in real time. Wide geographical spreads of participants in large-scale DIAs necessitate distributed deployment of servers to improve interactivity. In a distributed server architecture, the interactivity performance depends on not only client-to-server network latencies but also interserver network latencies, as well as synchronization delays to meet the consistency and fairness requirements of DIAs. All of these factors are directly affected by how the clients are assigned to the servers. In this paper, we investigate the problem of effectively assigning clients to servers for maximizing the interactivity of DIAs. We focus on continuous DIAs that changes their states not only in response to user operations but also due to the passing of time. We analyze the minimum achievable interaction time for DIAs to preserve consistency and provide fairness among clients, and formulate the client assignment problem as a combinatorial optimization problem. We prove that this problem is NP-complete. Three heuristic assignment algorithms are proposed and their approximation ratios are theoretically analyzed. The performance of the algorithms is also experimentally evaluated using real Internet latency data. The experimental results show that our proposed Greedy Assignment and Distributed-Modify Assignment algorithms generally produce near optimal interactivity and significantly reduce the interaction time between clients compared to the intuitive algorithm that assigns each client to its nearest server.

Optimizing Client Assignment for Enhancing Interactivity in Distributed Interactive Applications

Distributed interactive applications (DIAs) are networked systems that allow multiple participants at different locations to interact with each other. Wide spreads of client locations in large-scale DIAs often require geographical distribution of servers to meet the latency requirements of the applications. In the distributed server architecture, the network latencies involved in the interactions between clients are directly affected by how the clients are assigned to the servers. In this paper, we focus on the problem of assigning clients to appropriate servers in DIAs to enhance their interactivity. We formulate the problem as a combinational optimization problem and prove that it is NP-complete. Then, we propose several heuristic algorithms for fast computation of good client assignments and theoretically analyze their approximation ratios. The proposed algorithms are also experimentally evaluated with real Internet latency data. The results show that the proposed algorithms are efficient and effective in reducing the interaction time between clients, and our proposed Distributed-Modify-Assignment adapts well to the dynamics of client participation and network conditions. For the special case of tree network topologies, we develop a polynomial-time algorithm to compute the optimal client assignment.

Interactivity-Constrained Server Provisioning in Large-Scale Distributed Virtual Environments

Maintaining interactivity is one of the key challenges in distributed virtual environments (DVEs). In this paper, we consider a new problem, termed the interactivity-constrained server provisioning problem, whose goal is to minimize the number of distributed servers needed to achieve a prespecified level of interactivity. We identify and formulate two variants of this new problem and show that they are both NP-hard via reductions to the set covering problem. We then propose several computationally efficient approximation algorithms for solving the problem. The main algorithms exploit dependencies among distributed servers to make provisioning decisions. We conduct extensive experiments to evaluate the performance of the proposed algorithms. Specifically, we use both static Internet latency data available from prior measurements and topology generators, as well as the most recent, dynamic latency data collected via our own large-scale deployment of a DVE performance monitoring system over PlanetLab. The results show that the newly proposed algorithms that take into account interserver dependencies significantly outperform the well-established set covering algorithm for both problem variants.

On the treeness of internet latency and bandwidth

Existing empirical studies of Internet structure and path properties indicate that the Internet is tree-like. This work quantifies the degree to which at least two important Internet measures--latency and bandwidth--approximate tree metrics. We evaluate our ability to model end-to-end measures using tree embeddings by actually building tree representations. In addition to being simple and intuitive models, these trees provide a range of commonly-required functionality beyond serving as an analytical tool. The contributions of our study are twofold. First, we investigate the ability to portray the inherent hierarchical structure of the Internet using the most pure and compact topology, trees. Second, we evaluate the ability of our compact representation to facilitate many natural tasks, such as the selection of servers with short latency or high bandwidth from a client. Experiments show that these tasks can be done with high degree of success and modest overhead.

An empirical evaluation of internet latency expansion

The Internet's latency expansion determines the asymptotic performance of large-scale distributed systems (such as Peer-to-Peer systems), but previous studies on the Internet have defined expansion in terms of router-level hops. In this paper, we empirically determine the Internet's latency expansion characteristics using measurements from two different Internet topology datasets. Our results show that the Internet router-level topology exhibits a power-law latency expansion, in contrast to its exponential expansion rate in terms of hops.

Development of a multi-behavior based mobile robot for remote supervisory control through the Internet

We review the networked mobile robot systems and suggest taxonomy based on the three levels of control commands. The performance analysis result shows that direct control has potential difficulty for implementation due to the unpredicted transmission delay of the network. To tackle this problem, we have suggested the behavior-programming control concept to avoid disturbances of the Internet latency. For this purpose, primitive local intelligence of the mobile robot is grouped into motion planner, motion executor, and motion assistant, where each of a group is treated as an agent. They are integrated by centralized control architecture based on multi-agent concept, communicated through a center information memory. The event-driven concept is applied on the robot to switch the behaviors to accommodate the unpredicted mission autonomously. We have successfully demonstrated experimentally the feasibility and reliability for system through a performance comparison with direct remote control.