S-38.3310 Tietoverkkotekniikan diplomityöseminaari 09.05.2006

1. S-38.3310 Tietoverkkotekniikan diplomityöseminaari09.05.2006 Title: Automatic Bluetooth Radio Frequency Measurement System Author: Jussi Savolainen Supervisor: Prof. Sven-Gustav Häggman Instructor: Petteri Yrjälä, M.Sc. Work carried out at: Elcoteq Design Center Oy, Salo Elcoteq Presentation / Jussi Savolainen

2. Presentation outline • Background • Research problem • Research methods • Bluetooth essentials • Bluetooth RF measurements • System setup • Software implementation • Conclusions and further work Elcoteq Presentation / Jussi Savolainen

3. Background • Bluetooth RF conformance testing by far the most expensive (time and cost) of the conformance tests, because • off-the-shelf test systems > 1 M€ (cost) • response time using external test houses too long (time) • Projects need a heap of test data in a short amount of time for statistical analysis, etc. • Failing in type approval tests is expensive Elcoteq Presentation / Jussi Savolainen

4. Research problem • How to automatically perform the Bluetooth RF conformance tests according to Bluetooth Test Specification version 2.0+EDR in prequalification phase of the design • How to perform the tests simultaneously for a number of devices • How to support different Bluetooth products and product types Elcoteq Presentation / Jussi Savolainen

5. Research methods • Literary study (Bluetooth RF specification, Bluetooth test specification, measurement device vendor application notes, etc.) • Vendor audits/interviews • HW Designer interviews • UI usability study • Data storage study Elcoteq Presentation / Jussi Savolainen

6. Bluetooth essentials • Bluetooth connects portable or fixed equipment, and it is a cable replacing technology, which is cheap and robust with low power consumption • Technology initially developed at Ericsson in 1994 • Bluetooth SIG established in 1998, first version of specification out same year • Most recent version 2.0+EDR came out in 2004 with support to higher data rates than previously • Operates on unlicensed (but not unregulated!) 2.4GHz ISM band ps S S S sb M/S piconet 2 M S ps piconet 1 Scatternet with two piconets Elcoteq Presentation / Jussi Savolainen

7. APPLICATIONS OBEX WAP SDP TCS two-way voice RFCOMM control HOST L2CAP HOST CONTROLLER INTERFACE data LINK MANAGER CONTROLLER BASEBAND AND LINK CONTROLLER RADIO Bluetooth essentials – protocol stack • Bluetooth protocol stack is a fuzzy structure • Controller and Host can be separated using HCI, chipset and applications implemented separately • Thesis discusses mainly radio layer Elcoteq Presentation / Jussi Savolainen

8. LSB MSB ACCESS CODE HEADER GUARD SYNC PAYLOAD 72b 54b 5 µs 11 µs 16-8200b 2FSK PSK LSB MSB ACCESS CODE HEADER PAYLOAD 68/72b 54b 0-2745b Bluetooth essentials – packet structure • Basic rate 1Mb/s • Enhanced Data Rate 2Mb/s or 3Mb/s • in EDR packets modulation is changed during the burst from 2FSK to PSK (backwards compatible) • EDR mostly affects radio layer General basic rate packet format General enhanced data rate packet format Elcoteq Presentation / Jussi Savolainen

9. Bluetooth RF measurements - basics • Device Under Test (DUT) can be placed to test mode, which allows configuration and control of the DUT • Some tests must be performed under extreme temperature and voltage conditions • Tests divided in transmitter (TX), receiver (RX) and transceiver (TRC) measurements • TX and RX tests according to Bluetooth RF test specification • TRC tests according to ETSI EN 300 328 Elcoteq Presentation / Jussi Savolainen

10. Bluetooth RF measurements – TX tests • TX tests either power measurement as function of frequency or frequency as function of time Elcoteq Presentation / Jussi Savolainen

11. Bluetooth RF measurements – RX tests • RX tests are BER measurements performed under different stimulus conditions Elcoteq Presentation / Jussi Savolainen

12. Bluetooth RF measurements – TRC tests • Out-of-band spurious emissions measured according to ETSI EN 300 328 • Does not belong to Bluetooth conformance tests • Measures harmonics of the carrier signal, cabinet radiation and modulation products Elcoteq Presentation / Jussi Savolainen

13. RF Shield Climate chamber Multiplexer 1x12 Multiplexer 1x12 Relay box ATT Multiplexer 1x4 Multiplexer 1x4 Multiplexer 1x4 GSM Signaling GSM BT tester IQ CW Spectr An System setup • All Bluetooth RF conformance tests and out-of-band spurious emission measurement must be performed automatically with one setup • 12 DUTs measured simultaneously • Capable of measuring any Bluetooth device which implements at minimum the controller Elcoteq Presentation / Jussi Savolainen

14. System setup - equipment • Altogether ~ 200 k€ • Calibration of the transmission paths from 30MHz to 13GHz with 1MHz steps Elcoteq Presentation / Jussi Savolainen

15. Software implementation - UI Elcoteq Presentation / Jussi Savolainen

16. Software implementation – data storage • System creates ~50Mb/day of data  text files or excel sheets are not an option • Writer (test system/test engineer) and reader (customer project/RF designer) are separated • Graphs and reports must be easily extractable from database • Short response time for new graphs and reports Elcoteq Presentation / Jussi Savolainen

17. Conclusions and further work • This type of system is never finished as interface to a new DUT must be built every time and data storage is updated • Error handling updates • Calibration • Measurement equipment SW updates Elcoteq Presentation / Jussi Savolainen

18. ¿Questions? DANKE! Elcoteq Presentation / Jussi Savolainen

19. World’s leading EMS providerto communications technology customers Elcoteq Presentation / Jussi Savolainen