Ms Latency Research Articles

HARQ in Full-Duplex Relay-Assisted Transmissions for URLLC

The Release 16 completion unlocks the road to an exciting phase pertain to the sixth generation (6G) era. Meanwhile, to sustain far-reaching applications with unprecedented challenges in terms of latency and reliability, much interest is already getting intensified toward physical layer specifications of 6G. In support of this vision, this work exhibits the forward-looking perception of full-duplex (FD) cooperative relaying in support of upcoming generations and adopts as a mean concern the critical contribution of hybrid automatic repeat request (HARQ) mechanism to ultra-reliable and low-latency communication (URLLC). Indeed, the HARQ roundtrip time (RTT) is known to include basic physical delays that may cause the HARQ abandonment for the 1 ms latency use case of URLLC. Taking up these challenges, this article proposes a hybrid FD amplify-and-forward (AF)-selective decode-and-forward (SDF) relay-based system for URLLC. Over this build system, two HARQ procedures within which the HARQ RTT is shortened, are suggested to face latency and reliability issues, namely, the proposed and the enhanced HARQ procedures. We develop then an analytical framework of this relay based HARQ system within its different procedures. Finally, using Monte-Carlo simulations, we confirm the theoretical results and compare the proposed relay-assisted HARQ procedures to the source-to-destination (S2D) HARQ-based system where no relay assists the communication between the source and the destination.

Adaptive Spectrum Aggregation Regimen for Downlink NR-gNodeB and Device to Device Systems in 5G

Device to device communication (D2D) and internet of things are anticipated to rule the globe in the upcoming days. The ever increasing demand for data traffic and throughput pose a unique venture in fifth generation (5G) industry, including limited spectrum and mass device connectivity. The proposed system signifies the specifications putforth by third generation partnership project for D2D communication underlying cellular network. It is highly focused on design and development of its physical layer and link layer . This hybrid 5G non-standalone system is adaptive to operate in different frequency bands. Since the users of D2D and new radio g-NodeB apportion same spectrum, interference would be the resultant. To quell such interference effects and also to maintain high capacity and throughput, here two mechanisms, namely spectrum aggregation and scheduling are emphasized. More over scheduling on component carriers are implemented successfully. At the end, the experimental outcomes prove that the aforementioned two methods results in rapid data transfer rate and eminent capacity with 0.5 ms latency in the controlled path loss environment.

Maturation of Auditory Cortex Neural Activity in Children and Implications for Auditory Clinical Markers in Diagnosis.

Functional brain markers that can inform research on brain abnormalities, and especially those ready to facilitate clinical work on such abnormalities, will need to show not only considerable sensitivity and specificity but enough consistency with respect to developmental course that their validity in individual cases can be trusted. A challenge to establishing such markers may be individual differences in developmental course. The present study examined auditory cortex activity in children at an age when developmental changes to the auditory cortex 50 ms (M50) and 100 ms (M100) components are prominent to better understand the use of auditory markers in pediatric clinical research. MEG auditory encoding measures (auditory evoked fields in response to pure tone stimuli) were obtained from 15 typically developing children 6–8 years old, with measures repeated 18 and 36 months after the initial exam. MEG analyses were conducted in source space (i.e., brain location), with M50 and M100 sources identified in left and right primary/secondary auditory cortex (Heschl's gyrus). A left and right M50 response was observed at all times (Time 1, Time 2, Time 3), with M50 latency (collapsing across hemisphere) at Time 3 (77 ms) 10 ms earlier than Time 1 (87 ms; p < 0.001) and with M50 responses on average (collapsing across time) 5 ms earlier in the right (80 ms) than left hemisphere (85 ms; p < 0.05). In the majority of children, however, M50 latency changes were not constant across the three-year period; for example, whereas in some children a ~10 ms latency reduction was observed from Time 1 to Time 2, in other children a ~10 ms latency reduction was observed from Time 2 to Time 3. M100 responses were defined by a significant “peak” of detected power with magnetic field topography opposite M50 and occurring 50–100 ms later than the M50. Although M100s were observed in a few children at Time 1 and Time 2 (and more often in the right than left hemisphere), M100s were not observed in the majority of children except in the right hemisphere at Time 3. In sum, longitudinal findings showed large between- and within-subject variability in rate of change as well as time to reach neural developmental milestones (e.g., presence of a detectable M100 response). Findings also demonstrated the need to examine whole-brain activity, given hemisphere differences in the rate of auditory cortex maturation. Pediatric research will need to take such normal variability into account when seeking clinical auditory markers.

Review of optical and wireless backhaul networks and emerging trends of next generation 5G and 6G technologies

AbstractMobile Backhauling provides an interface between radio controller and base stations, mostly realized with a physical medium such as optical fibers or microwave radio links. With the huge mobile traffic due to an increase in mobile subscribers as well as deployment of 4G and 5G cellular network technologies, better solutions for capacity and coverage should be provided in order to enhance spectral efficiency. For 4G cellular networks, mobile backhaul networks deal with capacity, availability, deployment cost, and long‐distance reaches. In addition, mobile backhaul networks based on the 5G network incurs additional challenges that include 1 ms or less ultralow latency time requirements and ultra‐dense nature of the network capabilities. Therefore, for 5G technologies, latency delay, QoS, packet efficiency, noise suppression, and mitigation techniques, efficient modulation schemes, and packet network timing synchronization are some aspects that are to be dealt with while designing efficient backhaul approaches (wired/wireless). Current backhaul systems typically use cost‐effective solutions (eg, ‐Wi‐Fi and WiMAX)‐based packet‐switched technologies, especially Ethernet/Internet technologies and high‐speed optical fiber links.

A Light-Weight Deep-Learning Model with Multi-Scale Features for Steel Surface Defect Classification.

Automatic inspection of surface defects is crucial in industries for real-time applications. Nowadays, computer vision-based approaches have been successfully employed. However, most of the existing works need a large number of training samples to achieve satisfactory classification results, while collecting massive training datasets is labor-intensive and financially costly. Moreover, most of them obtain high accuracy at the expense of high latency, and are thus not suitable for real-time applications. In this work, a novel Concurrent Convolutional Neural Network (ConCNN) with different image scales is proposed, which is light-weighted and easy to deploy for real-time defect classification applications. To evaluate the performance of ConCNN, the NEU-CLS dataset is used in our experiments. Simulation results demonstrate that ConCNN performs better than other state-of-the-art approaches considering accuracy and latency for steel surface defect classification. Specifically, ConCNN achieves as high as 98.89% classification accuracy with only around ms latency over low training cost.

WIA-NR: Ultra-Reliable Low-Latency Communication for Industrial Wireless Control Networks over Unlicensed Bands

With the deep integration of information, communication and operation technologies, industrial wireless control networks (IWCNs) are playing key roles to drive industrial revolution. This article proposes a 5G-based new radio (NR) for IWCNs to realize ultra-reliable low-latency communication over unlicensed bands, namely WIA-NR. We first define a hierarchical star network topology, which employs a hybrid centralized and distributed system management architecture. Then, a three-layer protocol stack is defined by integrating some fundamental functions of 5G and proposing new functions to enhance reliability and timeliness. The key technologies include dynamic multi-channel listen before talk, adaptive channel hopping, over-the-air time synchronization, industrial data priority scheduling, aggregation and disaggregation. Finally, system-level simulations are performed to evaluate the performance of WIA-NR. The results show that WIA-NR can achieve less than 1 ms latency under 99.999 percent reliability constraint, which can well satisfy critical industrial control. Meanwhile, WIA-NR can harmoniously coexist with WiFi over unlicensed bands.

Latency impact on Quality of Experience in a virtual reality simulator for remote control of machines

In this article, we have investigated a VR simulator of a forestry crane used for loading logs onto a truck. We have mainly studied the Quality of Experience (QoE) aspects that may be relevant for task completion, and whether there are any discomfort related symptoms experienced during the task execution. QoE experiments were designed to capture the general subjective experience of using the simulator, and to study task performance. The focus was to study the effects of latency on the subjective experience, with regards to delays in the crane control interface. Subjective studies were performed with controlled delays added to the display update and hand controller (joystick) signals. The added delays ranged from 0 to 30 ms for the display update, and from 0 to 800 ms for the hand controller. We found a strong effect on latency in the display update and a significant negative effect for 800 ms added delay on latency in the hand controller (in total approx. 880 ms latency including the system delay). The Simulator Sickness Questionnaire (SSQ) gave significantly higher scores after the experiment compared to before the experiment, but a majority of the participants reported experiencing only minor symptoms. Some test subjects ceased the test before finishing due to their symptoms, particularly due to the added latency in the display update.

Exaggerated cortical representation of speech in older listeners: mutual information analysis

Aging is associated with an exaggerated representation of the speech envelope in auditory cortex. The relationship between this age-related exaggerated response and a listener's ability to understand speech in noise remains an open question. Here, information-theory-based analysis methods are applied to magnetoencephalography recordings of human listeners, investigating their cortical responses to continuous speech, using the novel nonlinear measure of phase-locked mutual information between the speech stimuli and cortical responses. The cortex of older listeners shows an exaggerated level of mutual information, compared with younger listeners, for both attended and unattended speakers. The mutual information peaks for several distinct latencies: early (∼50 ms), middle (∼100 ms), and late (∼200 ms). For the late component, the neural enhancement of attended over unattended speech is affected by stimulus signal-to-noise ratio, but the direction of this dependency is reversed by aging. Critically, in older listeners and for the same late component, greater cortical exaggeration is correlated with decreased behavioral inhibitory control. This negative correlation also carries over to speech intelligibility in noise, where greater cortical exaggeration in older listeners is correlated with worse speech intelligibility scores. Finally, an age-related lateralization difference is also seen for the ∼100 ms latency peaks, where older listeners show a bilateral response compared with younger listeners' right lateralization. Thus, this information-theory-based analysis provides new, and less coarse-grained, results regarding age-related change in auditory cortical speech processing, and its correlation with cognitive measures, compared with related linear measures.NEW & NOTEWORTHY Cortical representations of natural speech are investigated using a novel nonlinear approach based on mutual information. Cortical responses, phase-locked to the speech envelope, show an exaggerated level of mutual information associated with aging, appearing at several distinct latencies (∼50, ∼100, and ∼200 ms). Critically, for older listeners only, the ∼200 ms latency response components are correlated with specific behavioral measures, including behavioral inhibition and speech comprehension.

Rapid stimulus-driven modulation of slow ocular position drifts.

The eyes are never still during maintained gaze fixation. When microsaccades are not occurring, ocular position exhibits continuous slow changes, often referred to as drifts. Unlike microsaccades, drifts remain to be viewed as largely random eye movements. Here we found that ocular position drifts can, instead, be very systematically stimulus-driven, and with very short latencies. We used highly precise eye tracking in three well trained macaque monkeys and found that even fleeting (~8 ms duration) stimulus presentations can robustly trigger transient and stimulus-specific modulations of ocular position drifts, and with only approximately 60 ms latency. Such drift responses are binocular, and they are most effectively elicited with large stimuli of low spatial frequency. Intriguingly, the drift responses exhibit some image pattern selectivity, and they are not explained by convergence responses, pupil constrictions, head movements, or starting eye positions. Ocular position drifts have very rapid access to exogenous visual information.

Blockchain-enabled resource management and sharing for 6G communications

The sixth-generation (6G) network must provide better performance than previous generations to meet the requirements of emerging services and applications, such as multi-gigabit transmission rate, higher reliability, and sub-1 ​ms latency and ubiquitous connection for the Internet of Everything (IoE). However, with the scarcity of spectrum resources, efficient resource management and sharing are crucial to achieving all these ambitious requirements. One possible technology to achieve all this is the blockchain. Because of its inherent properties, the blockchain has recently gained an important position, which is of great significance to the 6G network and other networks. In particular, the integration of the blockchain in 6G will enable the network to monitor and manage resource utilization and sharing efficiently. Hence, in this paper, we discuss the potentials of the blockchain for resource management and sharing in 6G using multiple application scenarios, namely, Internet of things, device-to-device communications, network slicing, and inter-domain blockchain ecosystems.

SIMBA: A Skyrmionic In-Memory Binary Neural Network Accelerator

Magnetic skyrmions are emerging as potential candidates for next generation non-volatile memories. In this paper, we propose an in-memory binary neural network (BNN) accelerator based on the non-volatile skyrmionic memory, which we call as SIMBA. SIMBA consumes 26.7 mJ of energy and 2.7 ms of latency when running an inference on a VGG-like BNN. Furthermore, we demonstrate improvements in the performance of SIMBA by optimizing material parameters such as saturation magnetization, anisotropic energy and damping ratio. Finally, we show that the inference accuracy of BNNs is robust against the possible stochastic behavior of SIMBA (88.5% +/- 1%).

Furion: Engineering High-Quality Immersive Virtual Reality on Today's Mobile Devices

Despite the growing market penetration, today's high-end virtual reality (VR) systems remain tethered, which not only limits users' VR experience but also creates a safety hazard. In this paper, we perform a systematic design study of the “elephant in the room” facing the VR industry - is it feasible to enable high-quality VR apps on untethered mobile devices such as smartphones? Our quantitative, performance-driven design study makes two contributions. First, we show that the QoE achievable for high-quality VR applications on today's mobile hardware and wireless networks via local rendering or offloading is about 10X away from the acceptable QoE, yet waiting for future mobile hardware or next-generation wireless networks (e.g., 5G) is unlikely to help, because of power limitation and the higher CPU utilization needed for processing packets under higher data rate. Second, we present Furion, a VR framework that enables high-quality, immersive mobile VR on today's mobile devices and wireless networks. Furion exploits a key insight about the VR workload that foreground interactions and background environment have contrasting predictability and rendering workload, and employs a split renderer architecture running on both the phone and the server. Supplemented with video compression, use of panoramic frames, parallel decoding on multiple cores on the phone, and view-based bitrate adaptation we demonstrate Furion can support high-quality VR apps on today's smartphones over WiFi, with under 14 ms latency and 60 FPS (the phone display refresh rate).

A 9.52 ms Latency, and Low-power Streaming Depth-estimation Processor with Shifter-based Pipelined Architecture for Smart Mobile Devices

A 9.52 ms Latency, and Low-power Streaming Depth-estimation Processor with Shifter-based Pipelined Architecture for Smart Mobile Devices

Neural Mechanisms of Attentional Control for Objects: Decoding EEG Alpha When Anticipating Faces, Scenes,and Tools.

Attentional selection mechanisms in visual cortex involve changes in oscillatory activity in the EEG alpha band (8-12 Hz), with decreased alpha indicating focal cortical enhancement and increased alpha indicating suppression. This has been observed for spatial selective attention and attention to stimulus features such as color versus motion. We investigated whether attention to objects involves similar alpha-mediated changes in focal cortical excitability. In experiment 1, 20 volunteers (8 males; 12 females) were cued (80% predictive) on a trial-by-trial basis to different objects (faces, scenes, or tools). Support vector machine decoding of alpha power patterns revealed that late (>500 ms latency) in the cue-to-target foreperiod, only EEG alpha differed with the to-be-attended object category. In experiment 2, to eliminate the possibility that decoding of the physical features of cues led to our results, 25 participants (9 males; 16 females) performed a similar task where cues were nonpredictive of the object category. Alpha decoding was now only significant in the early (<200 ms) foreperiod. In experiment 3, to eliminate the possibility that task set differences between the different object categories led to our experiment 1 results, 12 participants (5 males; 7 females) performed a predictive cuing task where the discrimination task for different objects was identical across object categories. The results replicated experiment 1. Together, these findings support the hypothesis that the neural mechanisms of visual selective attention involve focal cortical changes in alpha power not only for simple spatial and feature attention, but also for high-level object attention in humans.SIGNIFICANCE STATEMENT Attention is the cognitive function that enables relevant information to be selected from sensory inputs so it can be processed in the support of goal-directed behavior. Visual attention is widely studied, yet the neural mechanisms underlying the selection of visual information remain unclear. Oscillatory EEG activity in the alpha range (8-12 Hz) of neural populations receptive to target visual stimuli may be part of the mechanism, because alpha is thought to reflect focal neural excitability. Here, we show that alpha-band activity, as measured by scalp EEG from human participants, varies with the specific category of object selected by attention. This finding supports the hypothesis that alpha-band activity is a fundamental component of the neural mechanisms of attention.

Benchmark and comparison between hyperledger and MySQL

In this paper, we report the benchmarking results of Hyperledger, a Distributed Ledger, which is the derivation Blockchain Technology. Method to evaluate Hyperledger in a limited infrastructure is developed. Themeasured infrastructure consists of 8 nodes with a load of up to 20000 transactions/second. Hyperledger consistently runs all evaluation, namely, for 20,000 transactions, the run time 74.30s, latency 73.40ms latency, and 257 tps. The benchmarking of Hyperledger shows better than a database system in a high workload scenario. We found that the maximum size data volume in one transaction on the Hyperledger network is around ten (10) times of MySQL. Also, the time spent on processing a single transaction in the blockchain network is 80-200 times faster than MySQL. This initial analysis can provide an overview for practitioners in making decisions about the adoption of blockchain technology in their IT systems.

Towards holistic secure networking in connected vehicles through securing CAN-bus communication and firmware-over-the-air updating

Abstract With the increasing connectivity in modern vehicle infrastructure, solutions are required to harden the vehicle’s electronic architecture against potential attacks. One of the most important concerns is to ensure vehicle systems take appropriate and safe actions to diminish the probability of cyber-attacks success and mitigate the ramifications of potential unauthorized access. In this work, we present a layered systematic approach to achieve these goals along with a real implementation on an electric motorcycle. The developed secure infrastructure involves secure interconnection mechanisms to ensure trustworthy communications for electronic control nodes; hardware firewall to prevent interference and unauthorized access from untrusted applications/firmware; separated OS instances for different execution environments to provide best possible support for apps with different requirements and to further isolate apps from each other; and finally secure deployment of apps/firmware to ensure that apps are deployed unaltered to the automotive platform. In particular, considering both in-vehicle’s units resource-constraints, in terms of cost and size, and security needs that emerge in open bus-based networks, we introduce a secure technology that helps to prevent cyber-attacks in automotive Controller Area Network (CAN) protocol which is often used in in-vehicle networks. This technology, which we call secure CAN (sCAN), respects standard CAN-bus and realizes security mechanisms implemented in software or hardware, while adding less than 1 ms latency on the communication. sCAN in synergy with on-chip hardware firewalling which controls authorization level of on-chip accesses, and finally, together with securing the deployment of firmware updating over the air, build a fully-layered approach for connected vehicles to protect system assets, such as application and device authenticity, integrity, confidentiality, and availability.

Photonic Switched Optically Connected Memory: An Approach to Address Memory Challenges in Deep Learning

Deep learning has been revolutionizing many aspects of our society, powering various fields including computer vision, natural language processing, and activity recognition. However, the scaling trends for both datasets and model size are constraining system performance. Variability of memory requirements can lead to poor resource utilization. Reconfigurable photonic interconnects provide scalable solutions and enable efficient use of disaggregated memory resources. We propose a photonic switched optically connected memory system architecture that tackles the memory challenges while showing the functionality of optical switching for deep learning models. Our proposed system architecture utilizes a “lite” (de)serialization scheme for memory transfers via optical links to avoid network overheads and supports the dynamic allocation of remote memories to local processing systems. In order to test the feasibility of our proposal, we built an experimental testbed with a processing system and two remote memory nodes using silicon photonic switch fabrics and evaluated the system performance. The optical switching time is measured to be 119 μs and an overall 2.78 ms latency is achieved for the end-to-end reconfiguration. The collective results and existing high-bandwidth optical I/Os show the potential of integrating the photonic switched optically connected memory to state-of-the-art processing systems.

Central auditory processing in adults with chronic stroke without hearing loss: A magnetoencephalography study

ObjectiveStroke lesions in non-auditory areas may affect higher-order central auditory processing. We sought to characterize auditory functions in chronic stroke survivors with unilateral arm/hand impairment using auditory evoked responses (AERs) with lesion and perception metrics. MethodsThe AERs in 29 stroke survivors and 14 controls were recorded with single tones, active and passive frequency-oddballs, and a dual-oddball with pitch-contour and time-interval deviants. Performance in speech-in-noise, mistuning detection, and moving-sound detection was assessed. Relationships between AERs, behaviour, and lesion overlap with functional networks, were examined. ResultsDespite their normal hearing, eight patients showed unilateral AER in the hemisphere ipsilateral to the affected hand with reduced amplitude compared to those with bilateral AERs. Both groups showed increasing attenuation of later components. Hemispheric asymmetry of AER sources was reduced in bilateral-AER patients. The N1 wave (100 ms latency) and P2 (200 ms) were delayed in individuals with lesions in the basal-ganglia and white-matter, while lesions in the attention network reduced the frequency-MMN (mismatch negativity) responses and increased the pitch-contour P3a response. Patients’ impaired speech-in-noise perception was explained by AER measures and frequency-deviant detection performance with multiple regression. ConclusionAERs reflect disruption of auditory functions due to damage outside of temporal lobe, and further explain complexity of neural mechanisms underlying higher-order auditory perception. SignificanceStroke survivors without obvious hearing problems may benefit from rehabilitation for central auditory processing.

Tactile Ring: Multi-Mode Finger-Worn Soft Actuator for Rich Haptic Feedback

This paper presents a novel finger-worn actuator capable of generating three distinctive haptic effects: static pressure, high-frequency vibration, and an impact. Our new design makes this multi-mode feedback with a single actuator possible in a small form factor. A ring-shaped air bladder made with soft silicone is inflated or deflated to generate feedback on the finger. The airflow is controlled by a pair of air valves connected to a compressed air tank. Besides static pressure, the actuator can generate high-frequency vibration with high acceleration and crisp impact feedback due to fast controllability of the valves with a strong air source and a lightweight bladder membrane. In addition, our special design and fabrication of the bladder - a combination of stretchable and non-stretchable membrane layers in the ring - allows for stronger feedback. Rendering algorithms for three kinds of feedback are also presented. The performance of the system and the characteristics of the feedback are thoroughly examined using a series of measurement experiments, revealing that the system can generate a static force up to 6.3 N, the vibration up to 2.2 g magnitude and 250 Hz frequency, and an impact with less than 5 ms of latency. The whole system weighs only 255 grams (4.5 grams for the actuator and 250 grams for the controller). Finally, we demonstrate the wearability of the system by integrating the modules into a self-contained haptic device in the form of a wristlet.

Multiplexing URLLC Traffic within eMBB Services in 5G NR: Fair Scheduling

5G New Radio (NR) is envisioned to efficiently support both enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC). Due to the severe constraint of URLLC traffic, the time resources used by eMBB are further divided into mini-slots. From the media access control (MAC) layer scheduling perspective, the resource allocation occurs on different timescales, and URLLC traffic is pre-emptively overlapped at the mini-slot timescale to obtain the strict requirements of URLLC (achieve 99.999% reliability within 1 ms latency). In this article, we analyze the multiplexing of eMBB and URLLC traffic in 5G downlink transmission, with the dual objectives of maximizing eMBB utility like proportional fairness for eMBB users while satisfying URLLC constraints. We formulate the resource allocation problem in each mini-slot as the integer programming (IP) problem with two solutions: 1) convex relaxation; 2) greedy algorithm. The simulation results show that our algorithms have a higher utility of eMBB users while satisfying the URLLC users' latency and reliability requirements than using basic round robin. The performance comparison between the two algorithms is extensively studied, and the choice of two algorithms in practice can be decided by the trade-off analysis investigated in this article.