1. Bluetooth Address or Name Sharing By Joseph Charboneau

2. Overview Bluetooth Establishing a Connection Inquiry Process Paging Procedure Problem Solution Conclusion

3. Bluetooth Bluetooth specifications were designed by Ericsson. Bluetooth was formalized by the Bluetooth SIG (Special Interest Group). Bluetooth SIG currently contains over 4,000 members. Bluetooth is a radio standard used to send and receive data packets while being low power, short range, and low cost.

4. Bluetooth (Cont.) Bluetooth has three different operating ranges. 1 Meter. 10 Meters. 100 Meters. The data rate for Bluetooth Version 1.2 is 1Mbps. The data rate for Bluetooth Version 2+EDR is 3Mbps.

5. Bluetooth (Cont.) Bluetooth operates in the license free ISM band from 2.4 to 2.485GHz. The frequency band is divided into 79 channels 1MHz wide. Bluetooth also uses frequency hopping at 1600 hops per second to help interference.

6. Establishing a Connection There are two major steps in making a connection in a Bluetooth network. Inquiry Process. Paging Procedure. The first step is the inquiry process and the second step is the paging procedure.

7. Inquiry Process Used by the master of a Bluetooth network to find a new slave. Used by a slave to find a master. During the process the master sends out inquiry requests. New slaves in the range will pick up the inquiry request. After the new slaves receives the inquiry request it generates a response.

8. Inquiry Process (Cont.) The response will contain the following information. Device Address or Device Name. Device Class. List of Services. Technical Information. The process uses a special physical channel.

9. Paging Procedure Targeted procedure. The master uses the response to generate a DAC. The master sends out the DAC. When a new slave receives its corresponding DAC it will respond by only sending out its DAC only.

10. Paging Procedure (Cont.) When the DAC is received the master will send its device address or device name and clock to the slave. When the slave receives the information from the master it will generate an acknowledgement. Then it will offset its native clock to match the master clock.

11. Inquiry Process and Paging Procedure T. Lindholm, “Setting up a Bluetooth Packet Transport Link,” http://www.cs.hut.fi/~ctl/btpacket.pdfhttp://www.cs.hut.fi/~ctl/btpacket.pdf

12. Problem Two devices trying to use the same device address or device name. The second device may not connect. Leads to data collisions. Leads to slaves receiving the same data from the master.

13. Solution There are three components to the solution. Updated Header. Table entries. Updated DAC.

14. Solution (Cont.) The first part of the solution is an updated header file. The header file will have an extra bit added to the front to determine the device number.

15. Solution (Cont.) The current header file is: The updated header file is: Silan Liu, “Bluetooth Technology,” http://progtutorials.tripod.com/Bluetooth_Technology.htm#_Toc41989845. http://progtutorials.tripod.com/Bluetooth_Technology.htm#_Toc41989845

16. Solution (Cont.) The second part of the solution is to use a table entry system. Each of the table entries contain: Device address or device name. Device number from the header. The table entries will be compared with every new slave that connects to the master.

17. Solution (Cont.) The third part is an updated the DAC. The DAC will be generated as before. The DAC will have an extra bit added from the device number bit from the updated header.

18. Solution (Cont.) New Inquiry Process: The process will begin in the same manner. The process will change after the response is received. New Paging Procedure: The DAC sent to the slave will be the updated DAC. The slave will return the DAC and the procedure will continue as normal.

19. Solution (Cont.) Master and slave communication.

20. Conclusion Problem of address sharing. Solution: Updated Header File. Updated DAC. Table.