WLAN LNA witch CMOS switch

What is the usage of the switch?
To switch multiband LNA into different desired frequencies?
Or the switches function to bypass the LNA? So that when the external LNAs are used, the on-chip LNAs can be switched off and bypassed in order to accommodate external LNAs and/or jamming signals.

typically bypass switch is to allow signal attenuation
when the incoming signal is strong (receiver too close to the transmitter), in order to avoid the overloading of receiver?s backend.
One example for WLAN 2.4 GHz would be MGA-71543 from Avago (formerly Agilent)

Cheers
Carlos