Latency (engineering)

About: Latency (engineering) is a research topic. Over the lifetime, 3729 publications have been published within this topic receiving 39210 citations. The topic is also known as: lag.

Method and apparatus for data transmission

Abstract: An embodiment of the invention relates to the technical field of wireless communications, particularly to a method and apparatus for data transmission, to solve the problem that a retransmission mechanism of an existing LTE system in the prior art can meet general LTE latency and reliability requirement but cannot meet high latency and reliability requirements brought by new business application The method in the embodiment of the invention comprises the steps in which, a receiving side receives data from a transmitting side through a plurality of paths and the received data from each path are the same; and the receiving side conducts multi-path data merging processing for the received data According to the embodiment of the invention, the transmitting side and the receiving side conduct data transmission through the plurality of paths, the transmitted data of each path are the same, the purpose of repeated transmission is therefore achieved, in this way, the reliability of data transmission can be ensured under the low latency requirement by making full use of different wireless channel connection

TPStream: low-latency and high-throughput temporal pattern matching on event streams

Abstract: Sequential pattern matching to detect a user-defined sequence of conditions on event streams is a key feature in modern event processing systems. However, the sequential nature of event based pattern matching has two major deficiencies. First, it is hardly possible to express complex temporal relationships between situations lasting for periods of time. Because events are equipped with a single timestamp only, the expressible temporal relations are limited to before/after/at the same time. Second, a sequential pattern is mapped to a continuous subsequence of the input stream starting with an arbitrary event, making efficient parallelization a hard problem. In this paper we present TPStream, a novel event processing operator for complex temporal pattern matching on event streams. TPStream first summarizes incoming events to situations lasting for periods of time, before it matches temporal patterns. With situations, temporal patterns can easily be defined based on Allen’s interval algebra. We also show that situation based temporal pattern matching can be efficiently executed in parallel using multiple threads on a single machine or multiple machines in a cluster. Finally, we present adaptive optimization components continuously tuning the execution strategy of TPStream towards the lowest possible result latency with respect to the overall system load. The results of our experimental evaluation show that TPStream is capable of processing high-volume event streams with both low latency and high throughput while outperforming applicable CEP solutions from academia and industry.

Impact of Link Heterogeneity and Link Correlation on Multi-Connectivity Scheduling Schemes for Reliable Low-Latency Communication.

Abstract: Industrial applications like closed-loop control or mobile robots pose strict latency and reliability requirements which cannot all be fulfilled by existing wireless communication systems. Multi-Connectivity (MC), i.e. using multiple communication paths at once, can be a measure to enhance latency and reliability of wireless communication systems. Different scheduling schemes, i.e. Load Balancing (LB), Packet Duplication (PD) or Packet Splitting (PS) can be utilized to distribute packets over the available links. The impact of link heterogeneity and correlation of latency among the links on the MC scheduling schemes needs to be investigated to evaluate the suitability of MC for reliable low-latency communications. In this paper, measurements of currently available technologies, i.e. small cell LTE and WiFi networks, are conducted. These measured traces are then fit to statistical distributions in order to be able to emulate different MC scheduling schemes over links with certain correlation and homo- or heterogeneity. Our evaluation reveals that homogeneous links are beneficial for all three scheduling schemes. The correlation of latency in time among the utilized links shows to have a strong impact on the performance of the different MC scheduling schemes. For uncorrelated links, PD can improve mean and tail latency and increase reliability. For correlated links on the other hand, PD has no gain compared to the single links, while PS can improve mean and tail latency performance. The number of links needed to fulfill latency and reliability requirements of industrial use cases is analytically derived for MC with PD over uncorrelated links.

OmniCast: Wireless Pseudo-Analog Transmission for Omnidirectional Video

Abstract: Wireless virtual reality (VR) applications that provide users extraordinary viewing experience are now drawing great attentions. Transmitting VR video via wireless channel to users’ head-mounted display devices efficiently with low latency is very important for many emerging VR applications. In this paper, we propose a pseudo-analog transmission framework named OmniCast, which provides graceful quality degradation and competitive performance for unpredictably varying wireless channels while featuring low latency, low complexity, and low energy cost. In particular, we analyze the influence of projection between the spherical representation and the 2-D plane representation, and derive a power optimization scheme to minimize the distortion on the sphere. In addition, we develop an approach to measure the efficiency of decorrelation transform in the spherical domain. Based on that, an appropriate transform option can be determined. Experimental results show that the proposed framework improves the transmission efficiency of omnidirectional videos, while achieving elegant quality degradation for channel fluctuation in a wide channel SNR range.