The present invention relates to a communications interface providing low power and ease of connectivity with burst high speed performance for transfer of large blocks of data when required. In particular, the invention relates to using a Bluetooth connection to a Bluetooth device as a control interface to establish and tear down a WLAN access point connection for use by the Bluetooth device.
In the Bluetooth protocol, connections are easily and quickly made via the Bluetooth® (www.bluetooth.org) pairing protocol, where the pairing may automatically occur between two devices, one a master and one a slave according to the protocol. The Bluetooth transfer rate is typically limited to less than 3 Mbps, and a low power variant of the Bluetooth protocol known as Bluetooth Low Energy (BLE) provides very low power consumption. Bluetooth is accordingly desirable for its ease of connection and low power consumption, and is the protocol of choice for small battery powered devices, such as medical devices worn by a patient, including EKG monitors, EEG monitors, glucose monitors, and other monitors engaged in measurement of physiological data. A problem arises in that some of these monitors may record long series of data measurements generating large blocks of data for subsequent download, and the 3 MBPS data rate limit of Bluetooth may require a long download time, during which interval, other support functions also require power that could otherwise be disabled or powered down.
In the Wireless Local Area Network (WLAN) protocols of the IEEE (www.ieee.org) series of standards described by 802.11, the infrastructure mode of the protocol is commonly used by participating devices, where a device which wishes to associate to the WLAN network does so as a station (STA) associating to an access point (AP) with other stations, and the STA makes an association request to the AP which is broadcasting a Service Set Identifier (SSID), and the association is completed with the assertion of an authentication KEY, of which many KEY_TYPEs are supported, including the series described in the Wireless Encryption Protocol (WEP), which has since been replaced by the series described in the Wi-Fi Protected Access (WPA), Wi-Fi Protected Access 2 (WPA2), and Wi-Fi Protected Access 3 (WPA3) series of standards. For each of these authentication and encryption protocols, the associating station must know which KEY and KEY_TYPE to use to associate with a particular AP. WLAN protocols, such as those under 802.11, including 802.11a, 802.11g, 802.11n, and 802.11ac, each provide a variety of data modulations and associated communication speeds, including data transfer speeds of 600 MBPS (for 802.11n and 40 Mhz channels), or higher (such as 802.11ac). The disadvantage of using WLAN for miniature battery powered wireless communication is that the STA configuration is much more complex and interactive than Bluetooth, and the standby power consumption during WLAN communications is much higher than the power consumption of Bluetooth. Additionally, where there are other access points in operation, an associating STA must know a-priori which SSID it is to associate with, and it must know the KEY and KEY_TYPE, which are typically not universally known to the STA prior to association to the particular AP.
It is desired to provide an improved data communications apparatus and method providing low power communications as well as high speed communications.
A first object of the invention is a communication system for a first Bluetooth low power device paired to a second Bluetooth device, the first Bluetooth device receiving or making a request for high speed data, the first Bluetooth device thereafter responding to the request by powering up and enabling a WLAN Access Point having an SSID, KEY_TYPE, and KEY, the first Bluetooth device transmitting the SSID, KEY, and KEY_TYPE to the second Bluetooth device, the second Bluetooth device thereafter enabling a WLAN interface and associating to the first station WLAN SSID using the KEY and KEY_TYPE, at least one of the first station or second station thereafter transmitting a block of high speed data to the other station using the WLAN interface, and at the end of the high speed data transmission, the first Bluetooth station or second Bluetooth station requesting the teardown of the WLAN STA connection, the request sent over either the Bluetooth interface or the high speed interface, the second Bluetooth station thereafter tearing down and powering down the WLAN AP until a future request is made.
A second object of the invention is a protocol for a low power first device, the low power first device being paired to a second device such as a tablet over a low power protocol such as Bluetooth, the second device or first device requesting a high speed connection over the low power protocol to the first device, the first device creating a WLAN AP with an SSID, KEY, and KEY_TYPE, the first device transmitting to the second device over the low power connection the WLAN credentials including the SSID, KEY, and KEY_TYPE, the first device transmitting or receiving a block of high speed data, the first device thereafter receiving an acknowledgement of receipt of the block of high speed data, the first device thereafter powering down the WLAN AP until a subsequent request for high speed connection.
A third object of the invention is a protocol for a high performance second device paired to a first low power device over a Bluetooth connection, the second device receiving a WLAN AP SSID, KEY, and KEY_TYPE over the Bluetooth connection, the second device thereafter making a WLAN association request using the SSID, KEY, and KEY_TYPE to the first device, the second device thereafter transmitting or receiving a block of high speed data, the second device thereafter tearing down the WLAN connection.
A Bluetooth connection is established between a first device such as a low power portable device having a low power interface such as Bluetooth, and a high speed interface, such as a configurable WLAN interface capable of Access Point (AP) infrastructure mode, and a second device such as a tablet computer which has a corresponding low power interface such as Bluetooth, and also a corresponding high speed interface such as WLAN configurable to be placed into a station (STA) infrastructure mode. The first device or second device indicates that it wishes to transmit high speed data. In one example of the invention, when the first device or second device receives or issues a high speed data request, the first device creates a WLAN access point (AP) with an SSID, KEY, and KEY_TYPE, and transmits the SSID, KEY, and KEY_TYPE over the Bluetooth connection to the second device. The second device, upon receipt of the SSID, KEY, and KEY_TYPE, makes an association request over WLAN to the SSID using the KEY and KEY_TYPE. Once the WLAN connection is established, the high speed data of the request is transmitted as a block of data over a short interval of time, thereby minimizing power consumption, and the WLAN connection is torn down, the first device tearing down and removing power to the WLAN AP interface, and the second device disassociating from the SSID until a future request for high speed data.
1) a request is made for a block of data which is either to be received by, or initiated by, low power device 302.
2) the low power device 302 enables the AP mode 310 as a WLAN access point and initializes the AP with an SSID, KEY, and KEY_MODE, transmitting those parameters to the tablet 340 using the Bluetooth link 303.
3) The tablet 340 receives the SSID, KEY, and KEY_MODE, and uses these parameters as a WLAN station to make an association request to the AP 302.
4) After association of the tablet 340 to the AP 302, the block of data is transmitted by the low power device 302 or tablet 340 from WLAN to WLAN via link 305.
5) Upon completion of the block of data transmission via WLAN, the tablet 340 disassociates from the AP 302, and the low power device 302 powers down AP mode 310, saving power but maintaining the respective Bluetooth interfaces on each end of link 303.
The use of Bluetooth for low power communications and WLAN for episodic high speed communications is shown for understanding the invention only. Alternative high speed interfaces include Zigbee or any high speed wireless interface requiring configuration parameters which may be passed across a low power interface for use by the high speed interface on a temporary basis for transmission of contiguous blocks of data at a higher speed and lower power consumption per bit than provided by the low power interface.
The present examples are provided for illustrative purposes only, and are not intended to limit the invention to only the embodiments shown.