Advertiser timing

Advertiser is started as early as possible, after a random delay in the range of 3 - 13 ms, asynchronously to any other role timing-events. If no roles are running, advertiser timing-events are able to start and run without any collision.

Figure 1. Advertiser

When other role timing-events are running in addition, the advertiser role timing-event may collide with those. The following figure shows a scenario of Advertiser colliding with Peripheral (P).

Figure 2. Advertiser collision
Advertiser collision

A directed high duty cycle advertiser is different compared to other advertiser types because it is not periodic. The scheduling of the single timing-event required by a directed advertiser is done in the same way as other advertiser type timing-events. A directed high duty cycle advertiser timing-event is also started as early as possible, and its priority (refer to Scheduling priorities) is raised if it is blocked by other role timing-events multiple times.

Extended advertising events are scheduled as single timing-events. The events can include packets sent on both the primary and the secondary advertising channels. The duration of an extended advertising event depends on the mode, data length, and on which PHY the advertising packets are sent. The SoftDevice will send as few secondary advertising channel packets as possible with each packet containing the maximum allowed amount of data. The packets are sent with an AUX frame space of 330 ┬Ás.