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Introduction
Published in Skip Pizzi, Graham A. Jones, A Broadcast Engineering Tutorial for Non-Engineers, 2014
Broadcasting is a communications service that possesses two fundamental and unique attributes: (1) Broadcasting is a point-to-multipoint service, meaning that a broadcast service originates from a single transmitter but is receivable by an unlimited number of receivers within the coverage zone of that transmitter. (Compare this to a point-to-point communications system, such as telephony, in which one device typically connects only to a single device at any given time.) (2) Broadcasting is a unidirectional service, meaning that it carries content only in a one-way path—from the broadcast station's transmitter to the listener's or viewer's receiver—with no provision for carrying signals back the other way. (Compare this to a bidirectional communications system, such as telephony, in which each user's device serves as both a transmitter and a receiver, and content can flow between users in both directions simultaneously.) These two characteristics have defined broadcasting since its origin and continue to do so today. Thus, all the systems described in this book will possess these two essential qualities.
Networking Basics for A/V
Published in Al Kovalick, Video Systems in an IT Environment, 2013
Who would want to use UDP when TCP is available? Well, here are a few of UDP’s advantages: UDP is very easy to implement compared to TCP.It has almost no software overhead and is very CPU efficient.It provides efficient A/V streaming (VoIP uses UDP and RTP to carry voice data for a call).There is no automatic rate control as with TCP; transmission metering can be set as needed.There is minimal delay from end to end.It supports point-to-multipoint packet forwarding (IP multicast).
Live Video and On-Demand Streaming
Published in Borko Furht, Syed Ahson, Handbook of Mobile Broadcasting, 2008
I. S. Venieris, E. Kosmatos, C. Papagianni, G. N. Prezerakos
Unicast delivery of content incorporates point-to-point stream delivery to each client. Unicast streaming services such as video on demand include streaming media content over fixed/mobile and wired/wireless networks to the subscriber/user. Such mobile video services are already provided to users on their mobile handsets by various service providers over cellular networks. Due to the nature of unicast delivery and bandwidth limitations, massive user demand is not supported in this mode, although a wide range of services and content can be provided. Multicasting, by contrast, delivers one stream simultaneously to multiple clients, assimilating point-to-multipoint transmission of content on communication networks where a subset of users must view the same content. Broadcast transport scheme is a special case of one-to-many delivery of multimedia content, because a single stream is delivered simultaneously to all communication network clients. Broadcast is a very efficient form of communication for popular content, as it can deliver this content to all receivers at the same time.
Comparative analysis of quaternion modulation system with OFDM systems
Published in International Journal of Electronics Letters, 2021
Anam Zahra, Qasim Umar Khan, Shahzad Amin Sheikh
Every communication system tries to achieve a lower bit error rate (BER) ensuring minimum data loss. With the increasing use of wireless communication technology, the demand for improved BER services over both wired and wireless links is also increased. New techniques are required to transfer data with better BER which existing techniques cannot support (Saxena & Prasad, 2003; Zou & Wu, 1995). In communication system, BER can be achieved at a certain limit at the expense of bandwidth or PAPR (Gangwar & Bhardwaj, 2012). There are various applications to achieve lower BER is more essential as compared to bandwidth such as military communication, point-to-point communication and point-to-multipoint communication (Gallagher, 1979). In the past, various techniques have been implemented in military communication systems to provide protection against noise interference. Spread spectrum is a modulation technique, extensively used in military (Zou & Wu, 1995). It resists interference and makes it hard for enemies to intercept, whereas in spread spectrum modulation technique, the bandwidth of transmitted signal is much greater than the bandwidth of original message. One technique to improve BER is CDMA; it has been used in military applications (Gangwar & Bhardwaj, 2012; Saxena & Prasad, 2003). CDMA is a multiple access technique used with spread spectrum, which allows numerous signals to occupy a single transmission channel in 2G and 3G wireless communications.
METAhaul framework of HPON for smart city access networks
Published in Journal of the Chinese Institute of Engineers, 2020
Kuo-Chang Feng, San-Liang Lee, Ching-Sheu Wang
Fixed and mobile network operators strive to accommodate the rapid explosion of fixed and mobile data, with network efficiency and densification measures, by adding transport networks to accommodate RAN evolution in heterogeneous network (HetNet) architecture (Mubarak, Esmaiel, and Mohamed 2018). The centralized baseband pool using the Radio over Fiber (RoF) scheme as mobile fronthaul (MFH) could be a feasible solution that supports wireline/wireless convergence on the physical layer, which shares fiber fronthaul links with fiber-to-the-x (FTTx) services (Yoshida 2018). The Time Division Multiplexing (TDM) Passive Optical Network (PON) is currently a strong competitor against the legacy Optical Transport Network (OTN) and Carrier Ethernet (CE) to construct the 5G transport network. It plays an essential role in successful 5G new radio (NR) deployments because of its point-to-multipoint (p2mp) topology for efficient use of fiber resources and its wide deployment around the world for fixed access services (ITU-T 2018). As the network capacity requirements increase along with the need for more flexibility and reconfigurability, Wavelength Division Multiplexing PON (WDM-PON) may be included. Therefore, a robust Hybrid PON (HPON) solution is needed to meet the above demands.
Asynchronous Wrapper-Based Low-Power GALS Structural QDMA
Published in IETE Journal of Research, 2022
B.K. Vinay, S. Pushpa Mala, S. Deekshitha
GALS techniques simplify timing analysis, time to market for an SoC circuit by reusing functional IP blocks. These structures adopt a modular approach by developing individual LS modules and they are integrated via port controllers with asynchronous logic developed using CAD tools. Furthermore, two-phase and four-phase handshake protocols are implemented by port controllers to initiate asynchronous communication between the sender and receiver LS modules. In this proposed methodology, a two-phase handshake protocol is adopted since it has a fewer transitions and reduced latency compared to a four-phase handshake protocol. The communication between two LS modules can be point-to-point or point-to-multipoint. The AW encapsulates port controllers besides the LS modules. The port controllers modeled by AFSMs for providing asynchronous communication between LS modules are made hazard-free by implementing the same using STG. The logical equations are mapped by the STG into standard library cells using a 3D tool, and finally the gate-level netlist is generated. Point-to-point communication between AW involves a single incoming and a single outgoing signal. The AW wrappers can be generalized to multi-point GALS with multiple incoming and outgoing signals, which cannot be activated concurrently as the arbiters are not used. Although point-to-multipoint GALS wrappers consume area on the chip compared to point-to-point GALS wrapper, they eliminate redundancy to a greater extent. They coordinate in sending and receiving data by activating LS modules accordingly through stretchable clocks. These stretchable clocks are chosen over plausible clocks to design the wrapper to handle reduced performance issues.