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Multimedia Communication and Networking Issues
Published in Sreeparna Banerjee, Elements of Multimedia, 2019
These considerations prompt the need for examining the QoS for multimedia data communication. The parameters which determine QoS are as follows: Data rate is the measure of the transmission speed in kilobits per sec, or megabits per sec.Latency is the maximum frame or packet delay. This indicates the maximum time needed from transmission to reception and is measured in milliseconds (ms). If the round-trip delay exceeds 50 ms in voice communication, then echo becomes perceptible; when the one-way delay is longer than 250 ms, talker overlap occurs.Packet loss or error gives the percentage error of the packet data transmission.Jitter or delay jitter is a measure of the smoothness of the audio/video playback. Jitter is related to the variance of frame/packet delays.Sync skew is a measure of the multimedia data synchronization, in ms. For accurate lip synchronization, the limit of sync skew is ±80 ms between audio and video. The general acceptable value is ±200 ms.
The Future of Fiber Optic Video Transmission
Published in David R. Goff, Kimberly Hansen, Michelle K. Stull, Fiber Optic Video Transmission, 2013
David R. Goff, Kimberly Hansen, Michelle K. Stull
The quality of digital video closely ties to the power of computer chips. The success and prevalence of video compression technology relates directly to Moore's Law and the power of computers. As computers, and associated ICs, become larger and faster, they can perform more calculations on each video frame. This increased computing power allows the implementation of even more elaborate algorithms. As the sophistication of compression algorithms improves, the compression ratio increases, which decreases the serial data rate while maintaining the same image quality. Today, MPEG-2 dominates as the video compression algorithm in use. Some systems still use the older MPEG-1, although it offers decidedly inferior results compared to MPEG-2.
Communication Techniques
Published in B K Bala, Energy Systems Modeling and Policy Analysis, 2022
Data rate is measured in units called bits/s or bps. For digital signals, the maximum data rate achieved by a transmission medium depends on the available bandwidth, the number of signal levels and the amount of noise present in the medium. Assuming the signal is binary encoded (consisting of two voltage levels) and the medium is noise-free, the data rate is expressed as: Maximum datarate=2×availablebandwidth
Architect’s role to improve in-building wireless coverage
Published in Cogent Engineering, 2020
Mohammad Tanvir Kawser, Zebun Nasreen Ahmed
The global mobile data traffic is expected to increase from 19.01 exabytes per month in 2018 to 77.5 exabytes per month by 2022, at an annual growth rate of 46% (Clement, 2019). The dramatic growth is apparently nonstop and its technical support is going to be a great challenge, especially within built spaces. Technically, the data rate experience directly depends on the signal-to-interference plus noise ratio (SINR) at the receiver end. This is because higher SINR allows the use of a higher level of modulation and coding scheme (MCS), which directly increases the bit rate. Moreover, a data packet needs to be retransmitted if it is not correctly decoded at the receiving end. As SINR increases, the possibility of correct recovery of the packet increases, reducing the retransmission of packets. The carrier signal strength is typically the worst inside buildings because building materials cause propagation losses, which is a very contemporary concern, as people typically stay inside buildings most of the time in the present world.
Wireless body area networks: a comprehensive survey
Published in Journal of Medical Engineering & Technology, 2020
Bahae Abidi, Abdelillah Jilbab, El Haziti Mohamed
The data rate can be defined as a speed at which data are transferred between the source and destination, measured by bytes per second but the transmission speed of a network is rated at megabits per second. In the medical field, the reliability can be obtained by the measurements of the data rates, the higher data rate devices deal with a lower bit error rate (BER) for instance 10−10, and low data rate devices deal with a higher BER, for instance, 10−4 [42].