Method and system for multi-stage device filtering in a bluetooth low energy device

#Certain embodiments of the invention relate to communication systems. More specifically, certain embodiments of the invention relate to a method and system for multi-stage device filtering in a Bluetooth low energy device.

#The Bluetooth low energy (BLE) is a specification that enables radio frequency communication operating within the globally accepted 2.4 GHz Industrial, Scientific & Medical (ISM) band. The BLE specification supports a physical layer bit rate of 1 Mbit/s over a range of 5 to 15 meters. The BLE wireless technology specification features two implementations, namely “dual-mode” and “single-mode”. In the dual-mode implementation, BLE functionality is an add-on feature within traditional Bluetooth, namely, Bluetooth Basic Rate (BR) and Bluetooth Enhanced Data Rate (EDR), sharing a great deal of existing functionality resulting in a minimal cost increase compared to existing Bluetooth BR/EDR enabled devices. The dual-mode implementation is targeted at mobile devices and personal computers. The single-mode implementation is power and cost optimized. The single-mode implementation features a lightweight Link Layer (LL) providing ultra-low power idle mode operation, simple device discovery and reliable point-to-multipoint data transfer with advanced power-save and encryption functionalities. The single-mode implementation is targeted at, for example, small, button-ell battery powered devices in, for example, sports and wellness, healthcare, entertainment and toys and mobile accessories product categories. The BLE offers connectivity between mobile devices or personal computers, and small button-cell battery power devices.

#Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.

#FIG. 1 is a diagram illustrating an exemplary Bluetooth Low Energy (BLE) communication system that is operable to support multi-stage device filtering in a Bluetooth low energy device, in accordance with an embodiment of the invention.

#FIG. 2 is a block diagram illustrating an exemplary Bluetooth Low Energy (BLE) device that is operable to perform multi-stage device filtering during device discovery, in accordance with an embodiment of the invention.

#FIG. 3 is a block diagram illustrating exemplary steps that may be performed by a Bluetooth Low Energy (BLE) device to concurrently support Resolvable Private Address (RPA) resolution and white listing during device discovery, in accordance with an embodiment of the invention.

#Certain embodiments of the invention may be found in a method and system for multi-stage device filtering in a Bluetooth low energy device. In various embodiments of the invention, a Bluetooth low energy (BLE) device such as a scanner and/or an initiator may receive advertising packets transmitted from an advertising BLE device (advertiser). The BLE device may be configured to filter the received advertising packets utilizing the hardware of the BLE device to search for advertisers of interest prior to packet processing. In instances where the advertiser is not found by the hardware device filtering, the BLE device may continue filtering the received advertising packets utilizing the firmware of the BLE device. Device identity information of preferred BLE devices may be partitioned to form a white list for the hardware, a white list for the firmware and a white list for the host for corresponding device filtering. The device identity information may comprise non-private device identity such as 48-bit Bluetooth low energy device addresses, and/or private device identity information such as Resolvable Private Addresses (RPAs) and/or Identity Root Key (IRK) for concurrent support of privacy and white listing. White listing is a method of blocking access from those devices not on white lists. The BLE device may start searching for advertisers of interest utilizing the hardware for device filtering so as to achieve a fast response time to an advertiser of interest. In instances where the advertiser is found by the hardware device filtering, the BLE device may perform a CRC check utilizing the hardware on the received advertising packets. A response may be sent by the hardware to the advertiser if the CRC check passes. In instances where the advertiser is found by the firmware device filtering, the device identity information of the advertiser may be inserted in the hardware white list for subsequent advertising packets from the advertiser. In instances where the advertiser is not found utilizing the firmware device filtering, the firmware may be operable to awaken the host to continue device filtering in the host depending on the device configuration. For example, the firmware may be operable to awaken the host based on attribute type information of the received advertising packets to process the received advertising packets for a service.

#FIG. 1 is a diagram illustrating an exemplary Bluetooth Low Energy (BLE) communication system that is operable to support multi-stage device filtering in a Bluetooth low energy device, in accordance with an embodiment of the invention. Referring to FIG. 1, there is shown a Bluetooth low energy (BLE) communication system 100 comprising a plurality of BLE devices, of which advertisers 110-120, a scanner 130, an initiator 140, a master device 150, and slave devices 160-170 are displayed.

#The BLE communication system 100 may be operable to utilize a frequency division multiple access (FDMA) scheme and a time division multiple access (TDMA) scheme to support vice and/or data communication. The communication system 100 may be configured to divide a plurality of physical channels, for example, 40 physical channels, into advertising channels and data channels per FDMA scheme. In advertising channels, a BLE device may function in a role as an advertiser, a scanner, or an initiator. In data channels, a BLE device may play a role as a master or a slave. The communication system 100 may be operable to utilize a TDMA based polling scheme in link layer communications between the master device 150 and the slave devices 160-170.