In data communication terminology, which type of channel is characterized by relatively slow data transfer rates compared to voiceband, wideband, and broadband channels?

Introduction:
Communication channels are often categorized by the range of frequencies they support and the corresponding data rates they can carry. This question checks your understanding of the standard terminology—narrowband, voiceband, wideband, and broadband—and which of these offers relatively slow data transmission.

Given Data / Assumptions:

• The comparison is conceptual and based on conventional definitions used in data communications.
• Data rate correlates with usable bandwidth and signal-to-noise ratio for a given modulation scheme.
• No exotic or proprietary enhancements are assumed.

Concept / Approach:

Narrowband channels occupy a small frequency range and consequently support lower symbol rates and throughput. Voiceband typically refers to the approximate 300 Hz to 3400 Hz band historically used for telephony modems, yielding modest data rates. Wideband and broadband describe progressively larger bandwidth allocations, enabling higher possible data rates when paired with suitable modulation and coding.

Step-by-Step Solution:

Verification / Alternative check:

Historically, narrowband systems (e.g., legacy signaling channels, low-rate telemetry) operate far below the rates of voiceband modems, while modern wideband/broadband systems enable high-speed data and multimedia transport. This aligns with the selection of narrowband as relatively slow.

Why Other Options Are Wrong:

Wideband channel: Larger bandwidth than voiceband/narrowband; supports higher rates.
Voiceband channel: Traditionally limited to telephony audio range; faster than narrowband but slower than wideband/broadband.
Broadband channel: Very wide bandwidth; supports high data rates by design.
Baseband channel: A signaling method on a medium; in many systems (e.g., Ethernet), baseband can be high-rate; not inherently the slowest.

Common Pitfalls:

Assuming 'voiceband' is the slowest because of dial-up history. While voiceband is limited, 'narrowband' is the more restrictive term encompassing even lower-rate channels.

Final Answer:

Narrowband channel