GB2416964A

GB2416964A - Bluetooth Proximity Detector

Info

Publication number: GB2416964A
Application number: GB0417647A
Authority: GB
Inventors: Richard Hoptroff
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-07
Filing date: 2004-08-07
Publication date: 2006-02-08
Also published as: GB0417647D0

Abstract

A system for using Bluetooth (RTM) radios for proximity detection and access control. A device for maintaining a table of ID codes and detecting whether a Bluetooth (RTM) radio with a corresponding ID code is within range. Described for use as a wireless key for a car or garage door. As the Bluetooth (short range radio link) module is built into another device (e.g. mobile telephone) there is no need for the user to carry an additional key.

Description

24 1 6964 Bluetooth Radio Proximity Detector This invention relates to

devices for secure access control. In applications such as vehicle access and garage door opening, various solutions exist.

Beyond the traditional serrated metal key, code-entry keypad systems and radio-fob systems have become the state of the art.

Code-entry keypad systems have the disadvantage that the code may be overseen when legitimate access is obtained. Radio-fob systems require a separate radio transmitter, which may be lost or one might forget to carry it.

An object of this invention is to provide a system which allows a Bluetooth radio to be used to provide access control. Each Bluetooth radio has a range of 10m and a unique ID code which it uses to identify itself. A device could thus test whether a specific Bluetooth device were in range, and if so, provide access as necessary. Such a device would have two main advantages. First, it uses an existing device that a user carries (e.g a mobile phone), rather than burdening him with a key. Second, it requires no action on behalf of the user to activate it; the presence of the radio alone is sufficient to provide access.

Accordingly, this invention is a device for maintaining a table of ID codes and detecting whether a Bluetooth radio with a corresponding ID code is within range.

Preferably the device detects the presence of Bluetooth radios in the following manner. A process known as "device discovery" is known to the art. The device performs a "device discovery" request, whereupon all "discoverable" Bluetooth devices reply with their ID codes. The discovery request is intended to be part of a greater process for establishing a communications link between devices. The present invention uses the request for a different purpose, that of proximity detection: no further communication need take place. The present invention compares the ID codes with those in its table. If any codes match, the proximity detector is triggered.

Preferably the device adds new Bluetooth devices to the table of ID codes in the following manner. A process known as 'pairing" is known to the art. In this process, once a Bluetooth radio has been "discovered", it may exchange passwords with it. If the passwords are identical, pairing is successful. Pairing is intended to be part of a greater process for establishing a secure communications link between devices. The present invention uses pairing for a different purpose: it interprets it as a request to be added to the table of ID codes. (This is not the same as storing the link key generated by the pairing process; such an action would be known to the art.) Page 2 A preferred embodiment of the invention will now be described with reference to the accompanying figures in which: FIGURE I shows a block diagram of the main components of the proximity detector.

FIGURE 2 shows a flow chart of functioning of the device.

As shown in figure 1, the proximity detector 1 comprises a microprocessor 2, memory 3 for storing a table of ID codes and Bluetooth radio 4 which may communicate with one or more other Bluetooth devices 6 whose presence is being detected. Logic output pin 5 goes high when a Bluetooth device 6 is in range of detector 1 and its ID code matches one of the codes in memory 3.

Figure 2 shows a flow chart of the functions of the microprocessor 2 relevant to the present invention. The microcontroller performs two functions alternately and repeatedly: It instructs Bluetooth radio 4 to performs device discovery to identify Bluetooth devices 6 within range. If the ID codes of any Bluetooth device 6 matches any of those in memory 3 then logic output pin 5 is set high' otherwise it is set low.

If Bluetooth radio 4 reports to microprocessor 2 that Bluetooth device 6 has initiated the pairing process, and the pairing is successful, the ID code of device 6 is added to the table in memory

Claims

Page 3 CLAIMS

1. A device comprising a microprocessor, memory and Bluetooth radio where the unique ID codes of other Bluetooth devices within range are obtained and where such ID codes are compared to ID codes in said memory.

2. A device as claimed in any preceding claim where the Bluetooth device discovery process is used to obtain the unique ID codes of other Bluctooth devices within range.

3. A device as claimed in any preceding claim where an ID code is added to said memory as a result of a Bluetooth device with that ID code initiating and successfully completing the Bluetooth pairing process with claimed device.

4. A method for actuating a device as follows: detecting the ID codes of Bluetooth radios within a vicinity, comparing the ID codes with ID codes stored in memory and actuating the device if one or more of the detected ID codes match those in the table.

Amendments to the claims have been filed as follows 1. A system for activating a device comprising: one or more communications radios operating in the FCC 5GHz (IJ-NII) or FCC 2.4GHz (ISM) frequency bands; where each said communications radio has a unique identification code; where each said communications radio is able to respond with said unique identification code when another said communication radio so requests; where two said communications radios can authenticate each other by comparing passkeys; an activating component which contains one such said communications radio; where said activating component records the unique identification codes of other said communications radios if they initiate authentication with it and if the passkeys match; where activating component requests the unique identification codes of other said communications radios in range and, if the unique identification code of any said communications radios in range matches the unique identification code of any of the communications radios previously recorded during authentication, activates the device.