Telecommunication Networks Chapter 8

To remove synchronization problems and restore the plesiochronous digital hierarchy (PDH) system for bulk telephone and data exchange.

SONET transmits multiple digital data streams simultaneously over optical fiber using LEDs and laser beams.

It performs multiplexing of signals and converts electrical signals to optical signals.

<p>The Regenerator acts as a repeater that increases the strength of the optical signal.</p> Signup and view all the answers

<p>The Path Layer moves signals from source to destination, the Line Layer moves signals across a physical line, and the Section Layer moves signals across a physical section.</p> Signup and view all the answers

<p>OAM stands for Operational Administration and Maintenance, and it is designed-in from the beginning for effective management.</p> Signup and view all the answers

<p>SONET is developed to transmit digitized telephone calls in T1 format over fiber optic cable at high speeds.</p> Signup and view all the answers

<p>The Add/Drop Multiplexer allows the addition of incoming signals or the dropping of signals from an existing stream.</p> Signup and view all the answers

<p>PDH stands for Plesiochronous Digital Hierarchy, and its primary function is to facilitate the multiplexing of digital signals in telecommunication networks.</p> Signup and view all the answers

<p>SDH stands for Synchronous Digital Hierarchy and provides a more standardized synchronization method compared to the independent clock frequencies used in PDH.</p> Signup and view all the answers

<p>SONET stands for Synchronous Optical Network, and it is a counterpart to SDH, primarily used in North America for optical transmission.</p> Signup and view all the answers

<p>A significant limitation of PDH is that access to a tributary rate requires step-by-step demultiplexing due to the stuffing used in the multiplexing process.</p> Signup and view all the answers

<p>American and European standards for PDH are not compatible with each other.</p> Signup and view all the answers

<p>Separate multiplexers are needed for each level in PDH to accommodate the varying data rates, which complicates the system's architecture.</p> Signup and view all the answers

<p>As data rates increase in PDH, the overhead percentage also increases, which can lead to less efficient use of available bandwidth.</p> Signup and view all the answers

<p>Network management features in PDH systems are vendor-dependent, which may lead to interoperability issues among different equipment manufacturers.</p> Signup and view all the answers

<p>The photonic layer corresponds to the physical layer of the OSI model.</p> Signup and view all the answers

<p>The section layer manages the fiber between regenerators and provides the necessary link for optical transmission.</p> Signup and view all the answers

<p>Each STS signal corresponds to an OC signal, with OC-N representing the optical layer for an STS-N signal.</p> Signup and view all the answers

<p>The two main configurations are Unidirectional Path-Switched Ring (UPSR) and Bidirectional Line-Switched Ring (BLSR).</p> Signup and view all the answers

<p>A virtual tributary (VC) refers to lower and higher order channels used to transport payloads of varying bit rates.</p> Signup and view all the answers

<p>MSOH is responsible for managing overhead data at the multiplex level to ensure efficient data transport.</p> Signup and view all the answers

<p>In a UPSR, traffic is rerouted in the opposite direction to maintain connectivity if a link fails.</p> Signup and view all the answers

<p>Lower order VC is used for low bit rate payloads, while higher order VC is for high bit rate payloads.</p> Signup and view all the answers

<p>BLSR allows traffic to flow in both directions around a ring and reroutes affected traffic to a protection path in case of a failure.</p> Signup and view all the answers

<p>SONET uses a frame structure of 9 rows and 90 columns, while SDH uses 9 rows and 270 columns.</p> Signup and view all the answers

<p>SONET has a fixed payload rate of 51.84 Mbps.</p> Signup and view all the answers

<p>SONET uses STS (Synchronous Transport Signal) and VT (Virtual Tributary) for transmission.</p> Signup and view all the answers

<p>An add/drop multiplexer allows insertion and extraction of signals in an STS line.</p> Signup and view all the answers

<p>The path layer, line layer, and section layer are responsible for signal movement in SONET.</p> Signup and view all the answers

<p>SONET uses NRZ encoding where the presence of light represents 1 and absence represents 0.</p> Signup and view all the answers

<p>An STS-3 frame can multiplex 34 DS1 channels, as each DS1 channel has a data rate of 1.544 Mbps.</p> Signup and view all the answers