Latency of BLE GATT Read Value Operation
Assume that a peripheral and central BLE devices have a connection established. Central is running a GATT service with a particular characteristic. Peripheral has searched for and found the service and characteristic, and it has all handles ready at hand.
What is the latency (in the peripheral) between issuing a read request for the characteristic and receiving value of the characteristic? I realize there is some back and forth between the peripheral and central, and thus the latency is not constant. What are the typical, min, and max latency values? Assume that the peripheral and central have no other BLE activity competing for resources.
In my experiments (using Laird BL654 dongle), I am getting circa 200ms delay but I do not know if this is the best/typical/worst case.
PS: I am talking about regular environment e.g. someone's house. It can, of course, take forever if there is a lot of traffic, bad connection etc.