DIGITAL T-CARRIERS AND MULTIPLEXING Flashcards
REVIEWER
The transmission of information (of any form) from one or more source to one or more destination over the same transmission medium
Multiplexing
What are the different Domains to accomplish Multiplexing?
Space Division Multiplexing, Time Division Multiplexing, Frequency Division Multiplexing, Wavelength Division Multiplexing
Domain of multiplexing where transmission from multiple sources occur on the same facility but NOT at the same time.
Time Division Multiplexing
Unsophisticated form or multiplexing that simply constitutes propagating signals from different sources on different cables that are contained on the same trench (transmission medium).
Space Division Multiplexing
Most prevalent encoding technique used for TDM (Time Division Multiplexing) digital signals.
Pulse Code Modulation (PCM)
Line speed of DS-0 (Digital Signal Level 0) channels?
64kbps
What is the Input Signal range and Sampling Rate of DS-0 channels?
Input Signal Range: 0-4kHz, Sampling Rate: 8kHz
How many bits per sample is in a TDM (Time Division Multiplexing) Frame?
8 bits per sample
Time it takes to transmit one TDM (Time Division Multiplexing) Frame. Equal to the time interval when sampling, therefore it is the reciprocal of the Sampling Rate.
Frame Time, 1/8000 seconds, 125 microseconds
In TDM (Time Division Multiplexing) the datastream is divided into _____ aka _____.
Time Slot, Epoch
In TDM (Time Division Multiplexing) what is the general formula for a channel’s data transmission rate?
Sampling Rate (Samples per Second) x TDM Frame (Bits per Sample)
in TDM (Time Division Multiplexing) what is the general formula for the line speed?
Number of Channels x Data Transmission Rate per Channel
Formula for Bit Rate?
Number of Channels x Input Bit Rate
Formula for Frame Rate?
Input Bit Rate (Convert to Bits) x Time Slot Bits
A communication system that uses digital pulses rather than analog signals to encode information.
Digital Carrier System
How many Voice Band Channels can a T1-Digital Carrier System TDM multiplex?
24 Voice Bands Channels
Bandwidth or Frequency range of Voice Bands or Audio Signals?
300Hz - 3kHz
Within a T1-Carrier System, _____ performs sampling, encoding and multiplexing of 24 voice band channels.
Channel Banks
Line Speed of T1-Digital Carrier System Time Division Multiplexing with the synchronization bit?
1.544Mbps
24 channels, 8bps/channel
192 bits per frame, +1 (sb)
193 bits per frame x 8000 samples per second
What does the “D-type” in D-type Channel Banks stands for?
Digital or Data Transmission
What type of encoding technique does D-type Channel Banks use?
Sign-Magnitude Code
How many frames in a superframe?
12 Frames
How many time slots per frame in a T1 Carrier System?
24 time slots for 24 channels
How many time slots per frame in a E1 Carrier System?
30 time slots for 30 channels
How many bits are encoded per time slots?
8 bits
A communication format where the frames are grouped together to increase synchronization, error detection and control.
Superframe TDM (Time Division Multiplexing) Format
In Superframe TDM (Time Division Multiplexing) Format, what are substituted in frames 6 and 12?
Signaling Bits
A _____ bit is substituted to frames 6 and 12 of Superframe TDM (Time Division Multiplexing) Format, what is substituted in frame 6? What is frame 6 called?
Signaling, Most Significant Bit (MSB), A-channel Signaling Bit
A _____ bit is substituted to frames 6 and 12 of Superframe TDM (Time Division Multiplexing) Format, what is substituted in frame 12? What is frame 12 called?
Signaling, Least Significant Bit (LSB), B-channel Signaling Bit
In Superframe TDM (Time Division Multiplexing) Format, what do you call frames 1-6?
A-highway
In Superframe TDM (Time Division Multiplexing) Format, what do you call frames 7-12?
B-highway
How many bits per frame?
193 bits
What do you call the extra bit per frame? Where is it placed?
Frame bit, at the beginning of the frame
How many frames in an Extended Superframe Format?
24 Frames
How many frames in the Extended Superframe Format is used as Synchronization Bit? What are the frame numbers?
6 Frames, Frame No: 4, 8, 12, 16, 20, 24
How many frames are used for Error Detection Code? What are the frame numbers?
6 Frames, Frame No: 1, 5, 9, 13, 17, 21
What do you call the Error Detection Code?
CRC-6 (Cyclic Redundancy Checking)
In Extended Superframe Format, how many bits is reserved for Management Channel?
12 bits
In Extended Superframe Format, what do you call the Management Channel?
Facilities Data Link (FDL)
What are the frame numbers used for Management Channel?
2, 3, 6, 7, 10, 11, 14, 15, 18, 19, 22, 23
The Extended Superframe Format supports a four-bit signaling word, where is it placed when encoded, and what frames?
Placed on second Least Significant Bit and on every 6th frame (6, 12, 18, 24).
Type of Communication Service that allows consumers to share a T-Carrier Line.
Fractional T-Carrier Service
In a T1/2 Carrier Service, How many channels are available and what is the line speed?
12 channels, 1.544Mbps/2 = 0.772Mbps
Central location where digital signals are routed to perform routine maintenance and troubleshooting.
Digital Cross-Connect (PPT) or Digital Signal Cross-Connect (Historical naming Convention) or DSX
Device that allows audio and video communications between users.
Picturephone Terminal
Device used to send, receive and process digital data.
Data Terminal
