Bluetooth low energy modulation (GFSK)

Question

What does Bluetooth modulation mean?

I knew there are some bluetooth modulation available to bluetooth such as DPQSK, 8DPSK and so on. However, I dont understand what does modulation mean in Bluetooth?

Further, the modulation of bluetooth is GFSK @ 2.4 GHz. What does "@ 2.4 GHz" mean here?

Answer 1

Modulation (in any wireless technology, not specific to Bluetooth) is a method of translating digital information like bits into wireless wave form which can be later transmitted over the air. Think of it as a function which converts bits into sine wave, which later on will be de-modulated by the receiver from sine wave into bits.

The @2.4 GHz means that Bluetooth operates at the frequency of 2.4 Giga Hertz. This is part of the Industrial Scientific & Medical (ISM) frequency bands which are allowed to be used without a license from the government (but are regulated). The 2.4GHz band starts at 2,400 MHz and ends at 2,500 MHz.