Radio Notification on connection events as a Peripheral

Similar to central links, peripheral links may also include multiple packet exchange within a single Radio (connection) Event.

Radio Notification events are as shown in Figure 1.

Figure 1. A Bluetooth® low energy peripheral link with multiple packet exchange per connection event

To guarantee that the ACTIVE notification signal is available to the application at the configured time when a single peripheral link is established, the following condition must hold (for exceptions, see Table 1):

tndist + tradio < tinterval

The SoftDevice will limit the length of a Radio Event (tradio), thereby reducing the maximum number of packets exchanged, to accommodate the selected tndist. Figure 2 shows consecutive Radio Events with Radio Notification signal and illustrates the limitation in tradio which may be required to guarantee tndist is preserved.

Figure 2. Consecutive peripheral Radio Events with Bluetooth low energy Radio Notification signals

Table 1 shows the limitation on the maximum number of 27 bytes long packets which can be transferred per Radio Event for given combinations of tndist and tinterval.

Table 1. Maximum peripheral packet transfer per Bluetooth low energy Radio Event for given combinations of Radio Notification distances and connection intervals. The data in this table assumes symmetric connections using LE 1M PHY, 27 bytes long packets, and full-duplex with Bluetooth low energy connection event length configured to be 7.5 ms and Connection Event Length Extension disabled.
tndist tinterval
7.5 ms 10 ms ≥ 15 ms
800 6 6 6
1740 5 6 6
2680 4 6 6
3620 3 5 6
4560 2 4 6
5500 1 4 6