Time-Assignment Speech Interpolation (TASI) Which statement about TASI operation is incorrect?

Introduction / Context:TASI is a classic analog time-division technique that improves trunk efficiency by exploiting the fact that speakers are silent a significant fraction of the time. Understanding what TASI does—and crucially, what it does not do—prevents misconceptions about speech clipping.

Given Data / Assumptions:

• TASI reassigns channels only during detected pauses (no active speech present).
• Voice activity detection (VAD) and hangover times control reassignment to avoid clipping.
• Propagation delays (e.g., satellite) are independent of TASI but may be subjectively conflated by users.

Concept / Approach:TASI dynamically assigns a smaller pool of channels to a larger set of talkers based on instantaneous activity. It should not “snatch” a bearer mid-syllable; instead it releases a channel when a talker pauses, then reacquires another channel rapidly when speech resumes.

Step-by-Step Solution:Identify the false claim: mid-speech snatching would audibly clip talk spurts and is avoided by design.Confirm other claims: rapid reassignment on speech resumption, higher utilization, and user confusion with satellite delay are historically documented.Note reliance on VAD/hangover → enables smooth operation.

Verification / Alternative check:Telephony references show TASI channel pools exceeding the number of bearer circuits via statistical multiplexing of talk spurts and silence periods.

Why Other Options Are Wrong:

• (b) True: quick reassignment is a TASI strength.
• (c) True: utilization gain is the raison d’être of TASI.
• (d) True: users sometimes misattribute artifacts to satellite delay.
• (e) True: VAD is fundamental to TASI decisions.

Common Pitfalls:

• Believing TASI removes channels mid-word; proper hangover timing prevents that.
• Confusing TASI (analog/statistical) with packetized voice methods.

Final Answer:It snatches the channel during a talker’s speech and may allocate it to another speaker needing it.