Radio spectrum refers to a range of radio frequencies. The bandwidth (eg. Broad band or Narrow band) of a radio signal is the difference between upper and lower frequencies of the signal. Consider the following statements:

1.    2G spectrum uses bandwidth of 30-200 KHz.

2.    3G spectrum uses bandwidth of 15-20 MHz.

3.    4G spectrum uses scalable channel bandwidths of 5–20 MHz, optionally up to 40 MHz.

Select the correct answer