Calculate the minimum time required to download two million bytes of information using each of the following technologies

a.    V.32 modem

b.    V.32bis modem

c.    V.90 modem

d.    Cable Modem

Solution

Formula to calculate time = total number of  bits to be downloaded/data rate in bps

= total number of bytes x8/data rate in bps

a. V.32

Here

Total data = 2,000,000 bits

Data rate = 9.6kbps = 9600 bps

Hence

 Time = (2,000,000 × 8) /9600 = 1668 s

b. V.32bis

Total data = 2,000,000 bits

Data rate = 14.4kbps = 14400 bps

 Time = (2,000,000 × 8) / 14400 = 1112 s

c. V.90

Total data = 2,000,000 bits

Data rate = 56kbps = 56000 bps

 Time = (2,000,000 × 8) / 56000  = 286 s

d. Cable Modem

We can calculate time based on the assumption of 10 Mbps data rate which is usually used:

Total data = 2,000,000 bits

Data rate = 10Mbps = 1000 Kbps = 10,000,000 bps

Time = (2,000,000 × 8) / 10,000,000 = 1.6 s