Systems and methods for low power short range wireless device communication scanning

Abstract

The present invention relates to a system and method for improving scanning in a low energy Bluetooth device. The host configures a scan interval length, and a scan window length. The scan window length is equal to or shorter than the scan interval length. Next, a link layer initiates a scan interval, and also generates a random delay. The random delay may be anywhere between zero and the difference between the scan window length and the scan interval length. The link layer waits for the delay to complete before scanning is performed by the transceiver. The transceiver scans for the duration of the scan window. After scanning, the system waits for the end of the scan interval before the link layer generates a subsequent randomized delay and the transceiver again scans for the duration o the scan window. This process may continue indefinitely until a connection is established. In some embodiments, the scan window may be subdivided into a number of sub-windows, each preceded by a randomized delay. In some embodiments, the scan window may be interrupted for other high priority radio procedures. In other embodiments, the link layer may identify these radio usage conflicts, and may recalculate the random delay in order to avoid the conflict entirely.