Chapter Questions
List the three major components of a channel bank. What function does each component perform?
What is the rationale for using bipolar signaling for digital transmission?
What four functions does a codec perform?
How was a sampling rate of 8000 per second selected for PCM?
Why is it necessary to quantize a PAM signal?
What is the difference between a chord and a step with respect to their spacing?
Under $\mu$-law encoding what would the PCM word 01011011 signify with respect to a PAM sample?
What does a basic T1 frame consisting of 193 bits represent?
How many framing bits per second flow over a DS1 line?
Assume that the D4 framing pattern ... 111 was received. What frame number should the receiving multiplexer expect next?
Why is the maximum data rate 56 kbps on a DDS circuit in North America?
What sources of clocking can a channel bank use?
Describe the 'ones density' requirement for a DS1 line. Why does a repeater require a minimum separation between marks on a DS1 line?
What information is conveyed in robbed bits?
Describe the difference between D4 and ESF framing.
What is the primary benefit of B8ZS coding?
Assume that the last one bit was negative and a byte has all zero bits. What is the inserted B8ZS code?
Discuss the relationship between a red and yellow alarm.
What is the purpose of a blue alarm?
What is the primary advantage of ESF framing over D4 framing?
Where does framing take place on a CEPT PCM-30 frame?
What framing signal uses a CRC-6?
What framing signal uses a CRC-4?
What is the advantage of acquiring T1 multiplexers with voice digitization modules that operate at 32 kbps instead of PCMs 64 kbps data rate?
Describe an example of vocoding.
Describe two methods of hybrid coding.
Assume you selected a voice digitization module that operates at 16 kbps . How many voice conversations could be carried on a Tl line?
Describe the two types of T3 circuits. Which type of T3 circuit would you use for a high-speed Internet connection?
What does a DS2 signal represent? How many DS2 signals are multiplexed to form a DS3 signal?
Describe the use of the C-bits in a DS3 signal.
Describe the use of ones density methods for DS1, DS2 and DS3 signals.
What interface would you use to obtain the ability to utilize the full transmission capability of a T3 circuit?
Describe the use of a T3 circuit as a homing point in a network.
Why can you expect transmission quality on ISDN facilities to be superior to existing analog facilities?
Discuss the data transmission rate differences between a basic access ISDN circuit and that obtainable on the switched telephone network.
What is an advantage of 2 B 1 Q line coding?
What protocol does ISDN's LAP-D resemble?
Describe an ISDN physical layer superframe.
What is the function of an ISDN Service Access Point Identifier?
Why is a Service Profile ID necessary?