Maintain multiple connection intervals/slave latencies in Bluetooth Low Energy network

bluetoothbluetooth low energyNetwork

Is it possible for a Bluetooth Low Energy network to operate with two different connection intervals and slave latencies?

To clarify, assume I have a network with one host and two slaves. These slaves are connected with interval A and slave latency B. A desired event occurs and the pairing between the host and one of the slaves modifies the connection interval to C and slave latency to D, while the other slave keeps operating at interval A and latency B. Is it possible for the host to maintain these two connection settings?

Best Answer

In short, yes. The connections are independent of eachother.

The slaves will not be communicating directly with each other, so they only have to discuss with the host/master about what connection parameters are allowed. The slave devices are the ones who try to negotiate the connection parameters, thereby allowing the master to decide whether or not to use these values.

As an example, a BLE compatible iOS device allows these settings:

● Interval Max * (Slave Latency + 1) ≤ 2 seconds
● Interval Min ≥ 20ms
● Interval Min + 20 ms ≤ Interval Max Slave Latency ≤ 4
● connSupervisionTimeout ≤ 6 seconds
● Interval Max * (Slave Latency + 1) * 3 < connSupervisionTimeout

When the slave tries to negotiate its settings, the host will respond to this, accepting the parameters if they are within the rules of what the master accepts.

Each slave will negotiate for themselves, establishing different connections with different settings, so that all slaves will have their preferred parameters on their own connections.

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