How to find wireless network frequency

There are situations where we need to find out our wireless network frequency.
Eg:- before purchasing network devices we need to verify whether we are in a 2.4 or 5 GHz network

Usage of iwlist command on a linux box,

iwlist <WIRELESS INTERFACE> scanning | grep -C3 <WIRELES_NETWORK_NAME>

Eg:

 iwlist wlp4s0 scanning | grep -C3 VM6292804
                    Frequency:2.412 GHz (Channel 1)
                    Quality=47/70  Signal level=-63 dBm 
                    Encryption key:on
                    ESSID:"VM6292804"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s