China
Africa
Explore chapters and articles related to this topic
Distribution of audio signals
Published in Michael Talbot-Smith, Audio Engineer's Reference Book, 2012
previously split into send and receive paths by the hybrid circuit and then the send and receive channels will be converted from analogue to PCM digital bit streams by Coder decoders (CODECs). Digital switching can be space division, which uses a different physical path to transmit the bit stream, or it can be time switching (time division multiplexing). Time-division multiplexing is a multiport switch in which all ports have access to the same physical path onto which transmitted bit streams from individual ports are allocated a unique time slot. The send and receive paths are interconnected by accessing the same time slot. The physical paths may be serial or parallel data highways. Large switches are constructed by using combinations of space–time–space switching, or time–space–time switching.
Data Communication
Published in Sunit Kumar Sen, Fieldbus and Networking in Process Automation, 2017
Multiplexing is the transmission of multiple signals simultaneously over a single link. Although they share the same medium for transfer of information, they do not necessarily occur at the same time or occupy identical bandwidth. Metallic wires, coaxial cables, satellite microwave, optical fiber, etc., may act as the transmission medium. At the receiver, demultiplexing is done to retrieve the original signals. Figure 1.7 shows the basic principle of operation of a multiplexer-demultiplexer (MUX-DEMUX) system. They are connected by a single link through which n channels transmit their information. A multiplexer combines the input signals into a single stream (many-to-one) while a demultiplexer (one-to-many) separates the signals into individual ones.
Light Attenuation in Optical Components
Published in Abdul Al-Azzawi, Photonics, 2017
The most important aspect of the fibre optic communication link is that many different wavelengths can be sent along a fibre simultaneously, without interference, in the 1310–1625-nm spectrum. The technology of combining a number of wavelengths onto the same fibre cable is known as wavelength division multiplexing (WDM). Furthermore, this technology experienced advanced development by using the dense wavelength division multiplexing (DWDM). WDM technology is presented in detail in the wavelength division multiplexing/demultiplexing chapter.
Traffic Grooming in PCE-based Architecture Combined with RWA Utilizing Dynamic Fiber State Information
Published in IETE Technical Review, 2018
Optical networks employing pure optical regeneration provide high data rates/speeds in the backbone network [1]. Wavelength division multiplexing (WDM) technique employed with optical amplifiers could multiplex a high number of wavelengths (or communication channels) on a single strand of fiber. Coarse/dense wavelength division multiplexing (C/D WDM) technology is driving backbone pure optical networks of the future, and providing these networks with data rates in the range of thousands of Gb/s in a single strand of fiber. Due to exponential increase of telecommunication, cellular, and internet user base around the world [2], this bandwidth will soon seem meager in comparison to backbone data rate requirements of the future. Traffic grooming is a process of combining various flows of data into a single channel thus optimizing existing bandwidth. Furthermore, traffic grooming can prioritize the flow of data as per various classes of service (CoS). Hence, an efficient traffic grooming algorithm (TGA) needs to be formulated to enhance the bandwidth utilization of these future telecommunication networks.
Ultra-fast optical switch with reconfigurable wavelength reuse functionality for dynamic flexible spectrum networks
Published in Journal of Modern Optics, 2019
G. M. Isoe, D. Kiboi. Boiyo, E. K. Rotich, T. B. Gibbon
In order to satisfy the explosive demand for high bandwidth, the IEEE 802.3ba task force has defined 100 Gbps Ethernet standard requirement for demanding applications such as ultra-high definition video streaming, large file sharing and video conferencing (1). Currently, research towards extending present networks by increasing channel data rates as well as wavelength multiplexing is considered a viable approach to increase capacities of optical fibre networks. For instance, the 100 Gbps Ethernet standard is based on 4 channels at 25 Gbps data rates in wavelength division multiplexing (WDM) systems with channel spacing of 5 nm for the metro-access networks.