It is 0x04 "Page Timeout". I think I understand why the ressource is busy. There can only be one paging in progress. Hmmm, then it is because of the physical limitations of Bluetooth and my workaround isn't really one.use hcidump and check the result code of the failing HCI connection complete event. Look them up in the Bluetooth specification. This may lights this behaviour a little bit more up.I guess you mean one paging process at one time per device? :)there is always an underlaying creation of an ACL link and this fails for you. The Bluetooth error codes don't map 1:1 to Unix error codes, so use hcidump to find out the Bluetooth error and look up what it means.