Long Distance Data Transmission

Frequency division multiplexing (FDM) and echo canceling (EC).

Simplex modems can only transmit signals in one direction, while full-duplex modems can transmit and receive signals simultaneously.

Asynchronous modems operate at slow to moderate rates, typically up to 1800 bps, and use framing bits with no clock to manage data transmission.

<p>Synchronous modems can operate at rates up to 28800 bps in audio lines.</p> Signup and view all the answers

<p>Equalizers help to offset the signal degradation due to the attenuation of telephone lines.</p> Signup and view all the answers

<p>PSTN signals are analog in nature, focusing on voice transmission, while digital signals transmit data in discrete units or bits.</p> Signup and view all the answers

<p>Synchronous modems commonly use phase modulation and integrated phase and amplitude modulation.</p> Signup and view all the answers

<p>It provides a method for error checking and ensures data integrity during transmission.</p> Signup and view all the answers

<p>Modulation converts digital signals into analog signals for transmission over communication channels.</p> Signup and view all the answers

<p>The local ANALOG loop tests the integrity of the local modem and associated connectors, while the remote DIGITAL loop checks the entire path including the carrier connection and remote modem.</p> Signup and view all the answers

<p>The V.54 protocol provides a standard for loopback tests used in modems to check the integrity of telephone circuits.</p> Signup and view all the answers

<p>Bit-error-rate testing identifies and resolves problems in communication links and assesses the quality of T1/E1 links.</p> Signup and view all the answers

<p>Digital signals are converted from their original format for transmission, whereas PSTN signals are typically analog and may require modulation for compatible transmission.</p> Signup and view all the answers

<p>Equalizers should be re-tuned when the line is replaced to ensure optimal operation due to changes in line parameters.</p> Signup and view all the answers

<p>Automatic equalizers tune themselves when a connection is established and continually adjust to the line conditions approximately every 15ms to 25ms.</p> Signup and view all the answers

<p>Synchronous modems operate at higher rates and can split channels for multiple consumers, unlike asynchronous modems.</p> Signup and view all the answers

<p>It is essential to move digital information efficiently from one location to another through these channels.</p> Signup and view all the answers

<p>Typical telephone lines have a usable bandwidth frequency range of 300 Hz to 3300 Hz.</p> Signup and view all the answers

<p>Digital signals can become distorted when transmitted over analog media due to bandwidth limitations.</p> Signup and view all the answers

<p>The data source is responsible for assembling data blocks with framing codes and any required error detection bits.</p> Signup and view all the answers

<p>A transparent modem does not interfere with the formatting of the data being transmitted.</p> Signup and view all the answers

<p>Equalizers should be tuned frequently when the line quality is low and its parameters change often.</p> Signup and view all the answers

<p>The fitness process can operate at rates of up to 2400 times a second, continuously adjusting based on the current line quality.</p> Signup and view all the answers

<p>A Split System Modem can split channels for several consumers, allowing different speeds of data transmission.</p> Signup and view all the answers

<p>The clock signal ensures that synchronous data is timed correctly for consistent transmission and reception.</p> Signup and view all the answers

<p>Digital signals, when transmitted over analog media, become distorted from their original square wave form.</p> Signup and view all the answers

<p>Data sources must assemble blocks to include framing codes and error-detecting bits as per the protocol requirements.</p> Signup and view all the answers

<p>The quality of digital information can diminish due to distortion and loss of signal integrity in low-bandwidth channels.</p> Signup and view all the answers

<p>Equalizers are tuned automatically during the connection establishment to adapt to line conditions.</p> Signup and view all the answers

<p>Short haul modems are cost-effective solutions for short distances, providing reliable communication without extensive error correction mechanisms.</p> Signup and view all the answers

<p>The ITU V.90 standard defines the 56K modem as capable of transmitting data at a maximum rate of 56,000 bits per second.</p> Signup and view all the answers

<p>Analog modems utilize simple modulation techniques without advanced error control or equalization devices, limiting their effectiveness at higher speeds.</p> Signup and view all the answers

<p>Signal attenuation in short haul modems occurs due to distance; it is mitigated by lowering the transmission rate to maintain consistent and error-free communication.</p> Signup and view all the answers

<p>The seven-bit ASCII code allows for the representation of up to 128 unique characters, including letters, numerals, and punctuation.</p> Signup and view all the answers

<p>Basic analog modems typically operate at a maximum data rate of 9600 bps, with some capable of reaching up to 64,000 bps.</p> Signup and view all the answers

<p>Short haul modems are optimized for distances up to 15 km, where their lower cost and reduced circuitry suffice for reliable communication.</p> Signup and view all the answers

<p>The ITU V.34 standard defines an upper limit data speed of 33,600 bps, while the ITU V.90 standard allows speeds up to 56,000 bps.</p> Signup and view all the answers

<p>The DSLAM packetizes the data to be sent to the Internet (ISP server).</p> Signup and view all the answers

<p>HDSL uses 2B1Q encoding, allowing operation without repeaters up to 12,000 ft, compared to T-1's 3200 ft limit.</p> Signup and view all the answers

<p>SDSL offers symmetric communication, supporting equal upload and download speeds, while ADSL has a higher downstream than upstream rate.</p> Signup and view all the answers

<p>VDSL can use coaxial, fiber-optic, or twisted-pair cables, making it adaptable for high-speed connections in various installations.</p> Signup and view all the answers

<p>The splitter separates the voice line from the data line to prevent interference between telephone and internet signals.</p> Signup and view all the answers

<p>ADSL requires professional installation of separate data lines and the use of splitters, increasing overall installation costs.</p> Signup and view all the answers

<p>ADSL uses DMT (Discrete Multitone Technique), allowing efficient utilization of available bandwidth for data transmission.</p> Signup and view all the answers

<p>HDSL can achieve data rates of up to 2 Mbps without repeaters.</p> Signup and view all the answers

<p>ADSL technology uses adaptive technology to test line conditions and adjust the data rate accordingly.</p> Signup and view all the answers

<p>DMT combines QAM and FDM to modulate data over multiple channels simultaneously, improving data transfer efficiency.</p> Signup and view all the answers

<p>The maximum achievable upstream bandwidth is 1.44 Mbps, but actual data rates are typically below 500 kbps due to deleted carriers in noisy frequencies.</p> Signup and view all the answers

<p>Downstream data transfer utilizes channels 31 to 255, achieving potential rates of up to 13.4 Mbps but typically below 8 Mbps due to noise-related channel deletions.</p> Signup and view all the answers

<p>Channel 0 is reserved for voice communication, while channels 1 to 5 are idle and provide gaps between voice and data.</p> Signup and view all the answers

<p>The splitter separates voice and data communications, allowing simultaneous use of the telephone and internet services.</p> Signup and view all the answers

<p>There are typically 24 channels available for upstream data transfer, using QAM modulation.</p> Signup and view all the answers

<p>The bandwidth is divided into 256 channels, each using approximately 4.312 KHz, with specific channels reserved for voice and control.</p> Signup and view all the answers

<p>The upstream bit rates range from 25 to 55 Mbps at distances of 3000 to 10,000 ft.</p> Signup and view all the answers

<p>Asymmetric configurations have higher bandwidth in one direction, suitable for web browsing, while symmetric configurations have the same bandwidth in both directions, suitable for video conferencing.</p> Signup and view all the answers

<p>HDSL technology supports a maximum rate of 2.048 Mbps over two pairs at distances up to 4.2 km.</p> Signup and view all the answers

<p>RADSL technology supports a variety of data rates that adapt based on the quality of the local loop, reaching up to 6 Mbps in one direction.</p> Signup and view all the answers

<p>A LAN extender is used to extend Ethernet beyond the standard distance limitation of approximately 100 meters (330 ft).</p> Signup and view all the answers

<p>VDSL technology can reach up to 52 Mbps in one direction, whereas ADSL typically supports lower speeds up to 6 Mbps in one direction.</p> Signup and view all the answers

<p>S-HDSL/SDSL transmits data over a single pair at a rate of 768 Kbps, providing symmetric bandwidth which is efficient for both upstream and downstream traffic.</p> Signup and view all the answers

<p>Symmetric configurations are suitable for video conferencing applications.</p> Signup and view all the answers

<p>A LAN extender allows for traffic forwarding between LANs over much greater distances than standard Ethernet.</p> Signup and view all the answers

<p>2BASE-TL can deliver a minimum of 2 Mbit/s and a maximum of 5.69 Mbit/s over distances up to 2700 m using a single copper pair.</p> Signup and view all the answers

<p>Media converters enable the use of fiber optic cable, extending links over greater distances and protecting data from noise and interference.</p> Signup and view all the answers

<p>10PASS-TS technology can transmit data over distances of up to 750 m.</p> Signup and view all the answers

<p>An Ethernet to Fiber Media Converter is used to interconnect copper-Ethernet devices over fiber in EMI-prone environments.</p> Signup and view all the answers

<p>LAN extenders can use various line encodings such as TC-PAM, 2B1Q, or DMT.</p> Signup and view all the answers

<p>Copper-based Ethernet connections are limited to a maximum distance of 100 meters, while fiber optic connections can extend much further.</p> Signup and view all the answers

<p>2BASE-TL requires unconditioned copper wiring without load coils for its operations.</p> Signup and view all the answers