Use Android as Bluetooth LE Peripheral without Advertising -

i want exchange data between 2 android devices using bluetooth le (and yes, know i'm not intendet exchanging data ble, thats not point here). started researching on topic , found out device used peripheral needs android 5, while core device need android 4.3.

the first step starting bluetoothgattserver on peripheral, advertise , start scanning core device. understand advertising added in android 5 bluetoothgattserver exists since android 4.3.

so if create bluetoothdevice object core should connect address string (which got), there no need advertising peripheral. if advertising isn't necessary stick android 4.3 without need of 5.0 device.

but somehow got strange feeling this, i'm getting wrong? suggestions?

advertising necessary peripheral since if no advertising, central can not find device(ok assume have peripheral mac address) if central not receive advertising not send out connect request, hence connection not set up.

i understand advertising added in android 5 bluetoothgattserver exists since android 4.3

i assume mean 4.3 can support ble , advertising/bluetoothgattserver exists on android 5 right?

if transfer few bytes, why don't use spp or opp.