Identification and location of personal area network device
A method, device and system are disclosed for geo-locating a device. In one embodiment, a first wireless transmitter/receiver pages a second wireless transmitter/receiver to establish a communication. A plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver are received by a wireless receiver. The reception time of packets transmitted by the first wireless transmitter/receiver and the second wireless transmitter/receiver is recorded. A time delay based at least in part on the recorded reception times of each packet is calculated, and a location of the second wireless device based on the calculated time delay is determined. A target location of the second wireless transmitter/receiver is determined based on a plurality of the determined locations of the second wireless transmitter/receiver.
1. A method for a wireless receiver, the wireless receiver being in communication with a first wireless transmitter/receiver that pages a second wireless transmitter/receiver to establish a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver, the wireless receiver and the first wireless transmitter/receiver being movable to a plurality of different locations, the method comprising:
at each of the plurality of different locations of the wireless receiver, and for each establishment of a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver:
recording the location of the wireless receiver and the first wireless transmitter/receiver;
receiving a plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver;
for each of the received plurality of packets:
recording reception times of packets transmitted by the first wireless transmitter/receiver and the second wireless transmitter/receiver;
if a predefined amount of time has passed without receipt of a packet:
calculating a time delay, td, based at least in part on the recorded reception time of each packet; and
determining a location of the second wireless transmitter/receiver based on the calculated time delay; and
determining a target location of the second wireless transmitter/receiver based on a plurality of the determined locations of the second wireless transmitter/receiver.
2. The method of claim 1 , wherein the wireless receiver, the first wireless transmitter/receiver and the second wireless transmitter/receiver are Classic Bluetooth Basic Rate devices.
3. The method of claim 1 , wherein the establishment of a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver is initiated by the sending of a page message from the first wireless transmitter/receiver to the second wireless transmitter/receiver, and wherein the plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver is increased by the transmission of a Link Management Protocol (LMP) name request from the first wireless transmitter/receiver to the second wireless transmitter/receiver.
4. The method of claim 1 , wherein the time delay, td, is determined as:
td =(Shift Time,MOD(2×slot time)−slot time)/2,
wherein Shift Time, MOD (2×slot time)>slot time; and
where “Shift Time” is a recorded reception time of a packet referenced to the recorded reception time of a first received packet by the wireless receiver, and
“slot time” is a time division multiplex (TDM) slot duration of a wireless system comprising the wireless receiver, the first wireless transmitter/receiver and the second wireless transmitter/receiver.
5. The method of claim 1 , wherein the method further comprises, for each of the received plurality of packets:
identifying a packet type; and
if the identified packet type is one of a first packet type and a second packet type, recording the reception time of the identified packet.
6. The method of claim 4 , wherein the first packet type is a POLL and the second packet type is a NULL.
7. A wireless receiver, the wireless receiver configured to receive packets from a first wireless transmitter/receiver that pages a second wireless transmitter/receiver to establish a communication between the first wireless transmitter/receiver and receive packets from the second wireless transmitter/receiver, the wireless receiver and the first wireless transmitter/receiver being movable to a plurality of different locations, the wireless receiver comprising:
a receiver configured to receive a plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver at each of the plurality of different locations of the wireless receiver and for each establishment of a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver;
a processing circuitry configured to:
at each of the plurality of different locations of the wireless receiver:
record the location of the wireless receiver and the first wireless transmitter/receiver;
for each of the received plurality of packets:
record reception times of packets transmitted by the first wireless transmitter/receiver and the second wireless transmitter/receiver;
if a predefined amount of time has passed without receipt of a packet:
calculate a time delay, td, based at least in part on the recorded reception time of each packet; and
determine a location of the second wireless transmitter/receiver based on the calculated time delay; and
determine a target location of the second wireless transmitter/receiver based on a plurality of the determined locations of the second wireless transmitter/receiver.
8. The wireless receiver of claim 7 where the wireless receiver is a Classic Bluetooth Basic Rate device.
9. The wireless receiver of claim 7 , wherein the establishment of a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver is initiated by the sending of a page message from the first wireless transmitter/receiver to the second wireless transmitter/receiver, and wherein the plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver is increased by the transmission of a Link Management Protocol (LMP) name request from the first wireless transmitter/receiver to the second wireless transmitter/receiver.
10. The wireless receiver of claim 7 , wherein the processing circuitry is further configured to determine the time delay, td, as:
td =(Shift Time,MOD(2×slot time)−slot time)/2,
wherein Shift Time, MOD (2×slot time)>slot time; and
where “Shift Time” is a recorded reception time of a packet referenced to the recorded reception time of a first received packet by the wireless receiver, and
“slot time” is a time division multiplex (TDM) slot duration of a wireless system comprising the wireless receiver, the first wireless transmitter/receiver and the second wireless transmitter/receiver.
11. The wireless receiver of claim 7 , wherein the processing circuitry is further configured to, for each of the received plurality of packets:
identify a packet type; and
if the identified packet type is one of a first packet type and a second packet type, record the reception time of the identified packet.
12. The wireless receiver of claim 11 , wherein the first packet type is a POLL and the second packet type is a NULL.
13. A wireless communication system movable to a plurality of different locations, the wireless communication system comprising:
a first wireless transmitter/receiver configured to:
initiate a paging sequence between the first wireless transmitter/receiver and a second wireless transmitter/receiver to establish a communication between the first wireless transmitter/receiver and the second wireless transmitter/receiver; and
a wireless receiver, comprising:
a receiver configured to receive a plurality of packets transmitted by the first wireless transmitter/receiver and transmitted by the second wireless transmitter/receiver at each of the plurality of different locations of the wireless receiver;
a processing circuitry configured to:
at each of the plurality of different locations of the wireless receiver:
record the location of the wireless receiver and the first wireless transmitter/receiver;
for each of the received plurality of packets:
record reception times of packets transmitted by the first wireless transmitter/receiver and the second wireless transmitter/receiver;
if a predefined amount of time has passed without receipt of a packet:
calculate a time delay, td, based at least in part on the recorded reception time of each packet; and
determine a location of the second wireless transmitter/receiver based on the calculated time delay; and
determine a target location of the second wireless transmitter/receiver based on a plurality of the determined locations of the second wireless transmitter/receiver.
14. The wireless communication system of claim 13 , wherein the wireless receiver, the first wireless transmitter/receiver and the second wireless transmitter/receiver are Classic Bluetooth Basic Rate devices.
15. The wireless communication system of claim 13 , wherein the first wireless transmitter/receiver is configured to initiate a Remote Name Request after initiating the paging sequence between the first wireless transmitter/receiver and the second wireless transmitter/receiver, and a communication connection between the first wireless transmitter/receiver and the second wireless transmitter/receiver is established.
16. The wireless communication system of claim 13 , wherein the processing circuitry of the wireless receiver is further configured to determine the time delay, td, as:
td =(Shift Time,MOD(2×slot time)−slot time)/2,
wherein Shift Time, MOD (2×slot time)>slot time; and
where “Shift Time” is a recorded reception time of a packet referenced to the recorded reception time of a first received packet by the wireless receiver, and
“slot time” is a time division multiplex (TDM) slot duration of a wireless system comprising the wireless receiver, the first wireless transmitter/receiver and the second wireless transmitter/receiver.
17. The wireless communication system of claim 13 , wherein the processing circuitry of the wireless receiver is further configured to, for each of the received plurality of packets:
identify a packet type; and
if the identified packet type is one of a first packet type and a second packet type, record the reception time of the identified packet.
18. The wireless communication system of claim 17 , wherein the first packet type is a POLL and the second packet type is a NULL.
19. The wireless communication system of claim 13 , wherein the wireless receiver and the first wireless transmitter/receiver are co-located when in operation.
20. The wireless communication system of claim 13 , wherein the wireless communication system further comprises a platform location module configured to provide the location of the wireless receiver, a general-purpose processor, and a time clock configured to provide a current time to the wireless communication system, which are interconnected to the first wireless transmitter/receiver and the wireless receiver.