Latency (engineering)

About: Latency (engineering) is a research topic. Over the lifetime, 7278 publications have been published within this topic receiving 115409 citations. The topic is also known as: lag.

Herpesviral Latency-Common Themes.

Abstract: Latency establishment is the hallmark feature of herpesviruses, a group of viruses, of which nine are known to infect humans. They have co-evolved alongside their hosts, and mastered manipulation of cellular pathways and tweaking various processes to their advantage. As a result, they are very well adapted to persistence. The members of the three subfamilies belonging to the family Herpesviridae differ with regard to cell tropism, target cells for the latent reservoir, and characteristics of the infection. The mechanisms governing the latent state also seem quite different. Our knowledge about latency is most complete for the gammaherpesviruses due to previously missing adequate latency models for the alpha and beta-herpesviruses. Nevertheless, with advances in cell biology and the availability of appropriate cell-culture and animal models, the common features of the latency in the different subfamilies began to emerge. Three criteria have been set forth to define latency and differentiate it from persistent or abortive infection: 1) persistence of the viral genome, 2) limited viral gene expression with no viral particle production, and 3) the ability to reactivate to a lytic cycle. This review discusses these criteria for each of the subfamilies and highlights the common strategies adopted by herpesviruses to establish latency.

Latency-and-Coverage Aware Data Aggregation Scheduling for Multihop Battery-Free Wireless Networks

Abstract: Battery-Free Wireless Sensor Networks (BF-WSNs) have been attracting increasing interests in the recent years. To reduce the latency in BF-WSNs, the Minimum Latency Aggregation Scheduling (MLAS) problem with coverage requirement $q$ is proposed recently, which tries to choose $q$ percent of nodes for communication and aggregation. In the existing method, the authors try to select nodes adaptively according to their energy status and schedule these nodes to achieve the minimum latency. Unfortunately, it cannot guarantee the distribution of the aggregated nodes and may result in these nodes being squeezed in a small area and a poor aggregation quality. Thus, we re-investigate the $q$ -coverage MLAS problem in this article, which can guarantee that the aggregated nodes are distributed evenly. Firstly, the 1-coverage MLAS problem, in which each node can be covered by at least one aggregated node, is studied. To reduce the latency, we intertwine the selection of aggregated nodes and the computation of a collision-free communication schedule simultaneously. Two algorithms are proposed by scheduling the communication tasks in the bottom-up and top-down manner respectively. Secondly, to satisfy the arbitrary coverage requirement $q$ , three algorithms are proposed to guarantee the aggregated nodes are evenly distributed in the network with a low latency. Additionally, the method to extend the proposed algorithms for the BF-WSNs with multiple channels is also studied. The theoretical analysis and simulation results verify that the proposed algorithms have high performance in terms of latency.

Low-variance stimulus-response latencies: Deterministic internal delays?

Abstract: When special procedures are used to minimize S-R latency variance, all responses fall within a distribution which has a standard deviation near 10 msec. This minimum SD is the same whether the mean latency is at the simple RT limit or as much as 400 msec longer than that limit. Over this range, the latency distribution is everywhere the same, symmetrical and highly-peaked and not typical of RT. Above a mean latency of 550 msec, variance increases as the mean increases in the way that would be expected if SD/M were constant for the delay in excess of 550. By way of interpretation, it is proposed that there are internal time delays which can be inserted into the S-R chain. These delays can be adjusted to any value between 0 and about 400 msec, but once set, they can be deterministic. Other considerations are discussed which suggest that the deterministic time delays are in the afferent part of the S-R chain.

Latency Optimization for Multi-user NOMA-MEC Offloading Using Reinforcement Learning

Abstract: Both non-orthogonal multiple access (NOMA) and mobile edge computing (MEC) have been recognized as important techniques in future wireless networks, and the combination of them has received attention recently. It has been demonstrated that in a dual-user scenario, the use of the NOMA can effectively reduce the latency and energy consumption of MEC offloading. However, the scenario of multiple users needs to be considered further, which is more practical. In this paper, we consider a NOMA-MEC system with multiple users and single MEC server, and investigate the problem of minimizing offloading latency. Through using the Reinforcement learning (RL) algorithm Deep Q-network (DQN) to select the users who offload at the same time without knowing the actions of other users in advance, we will obtain the optimal user combination state and minimize system offloading latency. Simulation results show that the proposed method can significantly reduce the system offloading latency in the multi-user scenario of applying NOMA to MEC.

Low Latency Random Access for Sporadic MTC Devices in Internet of Things

Abstract: This paper proposes a compressed sensing-based random access protocol (CS-RACH), which is suitable for servicing a large number of machine-type communication devices in Internet of Things (IoT) network. In CS-RACH, we utilize a larger number of unique preambles compared to conventional LTE-RACH, however, the compressed sensing technique makes it possible to simultaneously detect the users with high accuracy. Compared to the user detection in conventional LTE-RACH, the proposed user detection can get rid of preamble collisions and decrease the collision probability, thereby the overall access latency is significantly reduced. To prove the benefits of the proposed CS-RACH, we mathematically analyze and compare access latency performance of LTE-RACH and CS-RACH. In particular, based on the least absolute shrinkage and selection operator approach, we derive a normalized throughput, access success probability, and average access latency. Our simulation results also exhibit that the proposed CS-RACH considerably reduces the access latency under reasonable conditions in IoT environments.