Over-the-air firmware update for the ATmega128RFA1

I would like to get involved in the field of wireless transmission of 
firmware updates. However, I am somewhat overwhelmed, what I should buy 
and where I should begin at all.
I have a sensor ATmega128RFA1 which is wireless with a concentrator 
connected. The firmware is loaded with a JTAGICE3 device and Atmel 
Studio 7 and has 29682 bytes.

Is it possible to load the firmware with a device wirelessly? I also 
understand that then a bootloader must be installed on the ATmega128RFA1 
chip.
Can someone recommend such a device and a bootloader?

Any help is appreciated.