What term is used to measure modem speed?

What term is used to measure modem speed?

• A. Baud rate
• B. Bit rate
• C. Latency
• D. Throughput

Answer: (A)

The key idea here is distinguishing how many signaling changes the modem can make per second from how many data bits those changes carry. Baud rate measures symbols per second—the rate at which the modem can change the signal on the line. Each symbol can encode a certain number of bits depending on the modulation scheme, so the actual data rate (bits per second) can be higher or lower than the baud rate. So, when we talk about modem speed in terms of the signaling rate, baud rate is the appropriate term. For example, a modem might send 2400 symbols per second, and if each symbol carries, say, two bits, that yields 4800 bits per second, but the fundamental measurement of how fast the signaling is changing is still the baud rate. Latent delay (latency) is about how long a message takes to get from sender to receiver, not how fast the signaling changes. Throughput refers to the actual usable data delivered over time, which is related but is a resulting performance measure rather than the signaling rate itself. Bit rate is the data rate, but the term used to describe the speed of the modem’s signaling changes is baud rate.

The key idea here is distinguishing how many signaling changes the modem can make per second from how many data bits those changes carry. Baud rate measures symbols per second—the rate at which the modem can change the signal on the line. Each symbol can encode a certain number of bits depending on the modulation scheme, so the actual data rate (bits per second) can be higher or lower than the baud rate.

So, when we talk about modem speed in terms of the signaling rate, baud rate is the appropriate term. For example, a modem might send 2400 symbols per second, and if each symbol carries, say, two bits, that yields 4800 bits per second, but the fundamental measurement of how fast the signaling is changing is still the baud rate.

Latent delay (latency) is about how long a message takes to get from sender to receiver, not how fast the signaling changes. Throughput refers to the actual usable data delivered over time, which is related but is a resulting performance measure rather than the signaling rate itself. Bit rate is the data rate, but the term used to describe the speed of the modem’s signaling changes is baud rate.