Inter packet space in advertisements

[Ibrahim]

Hi, I have a simple question. I have looked through the Bluetooth specs, and Devzone, but I haven't found any answers.

What is the the time difference between the three packets (on ch 37, 38, 39) within one advertisement interval? Nordic's online power profiler suggests it is 283us for nonconnectable Advertisement, and 500us for connectable advertisement regardless of the payload size. I've tested it for nonconnectable advertisement with a sniffer, and it turned out to be 300-301us. Could you kindly tell me if there is a hard number? Thank you.

[Susheel Nuguru]

What you noticed on the sniffer seems to be the correct value

/** @brief The configured inter-frame space length in microseconds between the end of a packet
 *         (ADV_NONCONN_IND, SCAN_RSP, CONNECT_IND) and the start of the next advertising
 *         packet (ADV_NON_CONN_IND, ADV_IND, ADV_SCAN_IND, ADV_DIRECT_IND) in an
 *         advertising event. During this interval the advertising will switch to the next advertising channel.

 *         We have selected an inter-frame space of 300 us since that will match the minimum T_MAFS for
 *         advertising extensions. See Core specification v5.0, Vol 6, Part B, 4.1.2.
 *
 *         This value is to be used in @ref hal_rcs_radio_start_after_delay and advertising event length calculations.
 *
 */
#define LL_ADV_PRIMARY_LEGACY_SWITCH_LATENCY_US   (300)

[Ibrahim]

Thank you very much for the answer