Classic Bluetooth SPP, BLE GATT services and clients, notifications and reconnection. Radio roles and GATT client/server roles are separate design choices; define the application data contract explicitly.
Keep a local BlueZ GATT application’s exported object tree alive for the entire registration lifetime, and treat every new D-Bus owner as a new registration. Reusing the same object-path strings after process restart does not restore the previous application automatically. Applicability: BlueZ 5.79 local GATT server APIs and the matching gatt-database.c implementation on the system…
Recover a reset controller by rebuilding a new controller generation from durable product intent. Do not keep issuing commands through host objects that describe connections, advertising sets or credits the controller has already lost. The first recovery milestone is a synchronized host/controller state, not a successful reconnect to one peer. Applicability: Bluetooth Core 6.1 HCI…
Count HCI ACL packets against the controller pool that actually owns them, then return capacity from per-handle completion deltas or disconnect reclamation exactly once. Do not count application messages, radio packets or L2CAP credits as though they were the same resource. Applicability: Bluetooth Core 6.1 packet-based host-to-controller ACL flow control, with Linux v6.12 implementation examples….
Keep command-send allowance separate from the lifecycle of the operation a command starts. Command Status can permit another HCI command while the first procedure remains pending. Conversely, a later procedure-completion event does not automatically grant command credit. Applicability: Bluetooth Core 6.1 HCI command flow control, with Linux v6.12 source used as an explicitly narrower implementation…
Accept encrypted advertising through three separate gates: select authorized candidate key material, authenticate and parse the protected payload, then apply the product’s freshness policy. Successful decryption does not tell the receiver that an old authentic advertisement represents the broadcaster’s current state. Applicability: Core Supplement v12 Encrypted Data format, Bluetooth Core 6.1 GAP key-material procedure and…
Choose advertising mode from the interactions the product requires. Extended advertising cannot be both connectable and scannable. A design that depends on a scan response and a connection from the same extended set therefore needs revision before payload construction or radio tuning begins. Applicability: Bluetooth Core 6.1 advertising properties and Zephyr v4.2.0 extended-advertising APIs. This…
Admit advertising roles through a resource ledger with explicit priority and rollback. A controller’s supported-set count is not a guarantee that every proposed combination can be scheduled, and a stopped set is not necessarily a freed set. Track object ownership, controller configuration and radio activity separately. Applicability: Bluetooth Core 6.1 extended-advertising HCI and Zephyr v4.2.0…
Validate the IQ acquisition record before evaluating an angle estimator. Confirm the CTE type, sample format, packet status, reference-sample boundary and physical antenna sequence. Then verify the coordinate transform separately. A plausible angle can survive several mapping errors while pointing in the wrong direction. Applicability: Bluetooth Core 6.1 connectionless CTE IQ reports and Zephyr v4.2.0…
A product distance result should be a qualified estimate with provenance, not a floating-point number detached from its radio evidence. Establish supported roles and modes, collect matching results from both peers, preserve incomplete and aborted outcomes, and identify the estimator and calibration that produced the estimate. Applicability: Bluetooth Core 6.1 Channel Sounding and the Zephyr…
Decode power and path-loss reports into a connection-scoped evidence ledger before allowing them to drive adaptation. A new callback does not necessarily contain a new radio measurement, and an unavailable value must never become a large numeric path loss. Establish controller ownership of power changes before adding another control loop. Applicability: Bluetooth Core 6.1 connected…