We have a project with a device acting as a ble peripheral and a broadcast sink. First the ACL connection is set up and then it will scan for and sync to a broadcast with a configured name.
In the current prototype the time from starting to scan for broadcast and until the audio stream is synced and ready is typically 10-20seconds, with getting the BASE and BIG sync taking the longest. Is this expected with LE Audio broadcast or should it be possible to significantly reduce this delay?
Here are some logs that shows the timing (in ms):
[15552::INFO] (broadcast_sink.cpp:1116) Scanning for broadcaster XXX
[15634::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[15804::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[15976::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[16234::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[16404::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[16553::INFO] (broadcast_sink.cpp:999) Attempting to PA sync to the broadcaster with id 0x199823
[16554::INFO] (broadcast_sink.cpp:1006) Waiting for PA sync to complete
[16564::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[17424::INFO] (broadcast_sink.cpp:428) Found broadcaster with ID 0x199823 and addr 02:97:3C:BC:C5:EF (
[17744::INFO] (broadcast_sink.cpp:473) PA sync 0x2000dbd8 synced for broadcast sink with broadcast ID
[17744::INFO] (broadcast_sink.cpp:1013) Broadcast source PA synced, creating Broadcast Sink
[17745::INFO] (broadcast_sink.cpp:1020) Broadcast Sink created, waiting for BASE
[24944::INFO] (broadcast_sink.cpp:785) Received BASE with 1 subgroups from broadcast sink 0x2000e228
[24944::INFO] (broadcast_sink.cpp:791) Subgroup: 0 BIS: 0 index = 1
[24944::INFO] (broadcast_sink.cpp:621) Octets per frame: 40
[24944::INFO] (broadcast_sink.cpp:766) Codec info: id: 0x06, cid: 0x0000, vid: 0x0000, frequency: 2400
[24944::INFO] (broadcast_sink.cpp:830) Received SYNCABLE from broadcast sink 0x2000e228: unencrypted
[24944::INFO] (broadcast_sink.cpp:1027) BASE received, waiting for syncable
[24944::INFO] (broadcast_sink.cpp:1034) Waiting for broadcast code
[24945::INFO] (broadcast_sink.cpp:1041) Waiting for BIS sync request
[24945::INFO] (broadcast_sink.cpp:1048) Syncing to broadcast
[00:00:24.945,129] <dbg> bt_bap_broadcast_sink: broadcast_sink_ep_init: ep 0x2000e338
[00:00:24.945,159] <dbg> bt_bap_iso: bt_bap_iso_bind_ep: iso 0x2000e100 ep 0x2000e338 dir sink
[00:00:24.945,556] <dbg> bt_bap_broadcast_sink: broadcast_sink_set_ep_state: ep 0x2000e338 id 0x00 idle -> qos-configured
[24945::INFO] (broadcast_sink.cpp:1055) Waiting for BIG sync
[32144::INFO] (broadcast_sink.cpp:785) Received BASE with 1 subgroups from broadcast sink 0x2000e228
[32144::INFO] (broadcast_sink.cpp:791) Subgroup: 0 BIS: 0 index = 1
[32144::INFO] (broadcast_sink.cpp:621) Octets per frame: 40
[32144::INFO] (broadcast_sink.cpp:766) Codec info: id: 0x06, cid: 0x0000, vid: 0x0000, frequency: 2400
[00:00:32.150,909] <dbg> bt_bap_broadcast_sink: broadcast_sink_iso_connected: stream 0x2000ca34
[00:00:32.150,909] <dbg> bt_bap_broadcast_sink: broadcast_sink_set_ep_state: ep 0x2000e338 id 0x00 qos-configured -> streaming
[32150::INFO] (broadcast_sink.cpp:339) Stream 0x2000ca34 started
Both sides (broadcast sink and broadcast source) is nrf5340 and running nrf Connect v2.6.0, so we're also wondering if there has been changes to the audio implementation lately that might be beneficial for this issue?