Is sending advertisements required even when notifications are registered?

[sushant_shidore]

I've a scenario where BLE central has registered for notifications on some characteristic of a BLE peripheral. The frequency of change in data of this characteristic is very low, may be once in 10 minutes meaning that this BLE peripheral will send notifications quite rarely. Now, say if the central device got reset and now wants data from the peripheral immediately.

What should be done here since the peripheral could be in sleep mode and would wake up and advertise for the notification only when its characteristic data changes?

Do I need to make the peripheral send periodic advertisements even when it has seen no change in its data, just to give an opportunity to the central device for making a connection and reading the data?

Won't these 'dummy' advertisements affect the peripheral's battery life?

What is the standard practice followed in such kind of scenarios?

[RK]

This seems remarkably similar to your last question

devzone.nordicsemi.com/.../

"the peripheral could be in sleep mode and would wake up and advertise for the notification only when its characteristic data changes" shows you're somewhat confused about advertising mode vs connection mode. Advertisements are done before connection, after connection there are no advertisements, just read/write/notify/indicate and the devices exchange constant connection packets.

[RK]

ok you really need to go and read some information about the BTLE protocol and how it works and how little information you can send or how much etc etc. so you understand the modes of operation.

Even in connection, with no new data, the device spends 99% of its time asleep.

Also go and look for the resource (Resources tab at the top of the screen) for the online power profiler. That will give you an idea of the power consumption for various scenarios of just advertising, in connection etc.