Wireless 2002 IEEE Seattle Section

1. Wireless 2002IEEE Seattle Section Communications Society Computer Society Electromagnetic Compatibility Microwave Theory and Techniques

2. Agenda • Introduction to Wireless Technology • Bluetooth™ Application Development • Rationalizing Bluetooth™ in a Wireless World • Antenna Design for Wireless Products • Physical Layer Overview of Wireless LAN Modems and RF Testing • Bluetooth™ Compliance Testing

3. Introduction to Wireless Technology Joe Decuir Chair, Seattle Section IEEE Communications Society

4. Agenda • Wireless technologies • WAN, LAN, PAN • Some detail on Cellular • Scenarios • Design issues • Software • Radios/modems • Antennas • Testing and Certification

5. Todays’ Questions • For designers of devices and systems • Where would wireless technology help my product? • What kind of wireless technology would fit? • What are the design issues? • Where can I find solutions? • Where can I find more information? • How do I get my product tested and certified to sell?

6. Why Wireless? • Wires are fast • Wires are secure • Wires conserve power But: • Wires have to be made • Wires have to be installed • Wires may have to be removed • Wires are often in the way • Wires may be too short

7. Wireless Radio Types • There are several general classes of wireless radios, trading off range, power and data rate: • Satellite: video distribution, GPS, paging • Wide Area Networking: cellular, fixed wireless • Local Area Networking: e.g. 802.11 • Personal Area Networking: e.g. Bluetooth™ • Today’s focus: WAN, LAN and PAN

8. Wide Area Wireless Uses • The driving applications are paging and mobile telephony. • Paging is one-way, with simple low power receivers, low bit rate and limited uses. • The cellular networks were built and maintained to support two-way voice. • Like the Public Switched Telephone Network, the cellular networks have been extended to support new data services.

9. Early Cellular Systems • Because the mobile unit has to transmit, power is restricted, and therefore range. • A huge infrastructure of base stations had to be constructed to make the system viable. The pattern of coverage cells gives it these systems their name. • The early systems were voice only, with FM voice modulation and frequency division between callers.

10. Cellular System Evolution • The success of early systems came at a tremendous cost: all those base stations • The second generation systems all use digital techniques to reduce the amount of spectrum, time and power required to support telephony services. • The direct benefit to the service providers is to serve many more subscribers with the same number of cell towers.

11. Digital Cellular: TDMA • The air link uses digital modulation, with some error control on that link. • Voice is compressed to between 14 and 5 kbit/s using DSPs in the phones. • The earlier designs used time division (TDMA) to serve several individual phones in each frequency band pair formerly used to serve one voice caller. Examples: IS-136 TDMA, GSM • Advantages: relative simplicity, easy migration from analog cellular technologies

12. TDMA parameters • 30 KHz channels (like analog & CDPD) • 20 msec speech frames • 24.3 kbaud symbol rate • 3 time-slots/users • 7.4 kbps ACELP speech coding • 1/2-rate channel coding on important bits interleaved over 2 bursts in 40 msec • Differential pi/4-QPSK modulation

13. Digital Cellular: CDMA • Code Division Multiplexed Access • Qualcomm and other companies had developed Spread Spectrum techniques for communication. Advantages: • Resistance to interference • Secure, difficult to eavesdrop • Can support multiple non-interfering users in the same chunk of spectrum. • Theoretically, more users/Hz than TDMA.

14. Why CDMA? • Higher capacity • Improved performance in multipath by diversity • Lower mobile transmit power = longer battery life • Power control • Variable transmission rate with voice activity detection • Allows soft handoff • Sectorization gain • High peak data rates can be accommodated • Combats other-user interference = lower reuse factors

15. Digital Services on Cellular • The first add-on service to the PSTN was data, using a succession of modems, from Bell 103 and V.21 all the way to V.90. • Data modems were tried on analog cellular, but performance was poor.

16. Cellular Digital Packet Data • As a first step to offer packet data, some analog cellular providers developed a technique to grab bursts of unused capacity in the dead time available between calls, at 19.2kbps. • CDPD was offered. It is useful, where available. • Its success was impaired by the need to deploy new infrastructure, new mobile hardware, and connect that to useful applications. Digital cellular improvements will make it obsolete.

17. Digital Cellular Data Services • Traditional PSTN data modems can not work on digital cellular at all, but the need for data services was recognized. • All three types of digital cellular systems included provisions to offer modem-style circuit mode data services: • Add PSTN modem pools between the cell base stations and the PSTN • The modem’s logical serial port is stretched over the digital air link • The cell phone exposes a standard modem command language through an attached cable.

18. Data Service Speed Limits • The circuit mode data rates are constrained to the rates allocated to the phone to carry voice: 9600-14400 bps. • These rates support the kinds of applications common when the systems were designed: e.g. text-based email. • By the time these services were deployed, Web access had become the dominant data application; these rates are too slow.

19. Migration to Packet-Based Service • Common data applications are not continuous, they are bursty. • Circuit mode services spends transmit power, and cell tower time, sustaining connections that are used in bursts. • The control channels included in the digital cellular air interfaces make small packet traffic easy to add, such as the popular Short Messaging Services (SMS).

20. Speeding up Cellular Data • Step one: add packet-based service, with rapid fine grained allocation of spectrum, time slots, code space, e.g. • GPRS = General Packet Radio Service • Cdma2000 1xRTT • EDGE • Step two: Redesign as a high bandwidth packet-based service • “3G Cellular”

21. 1999 2000 2001 2002 2003 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Wide-Area Wireless Summary Wide Area Wireless US Summary Mobitex 8, DataTAC 19.2 Packet CDPD 19.2 Packet GSM 9.6 Circuit-Switched General Deployment iDEN - Nextel - 9.6 Packet and Circuit-Switched Trials Start General Deployment Trials cdmaOne Circuit-Switched Verizon 14.4 - IS-95A Sprint Limited Deployment cdma2000 1XRTT Trials Start 153 Kbps - Packet General Deployment 19.2 Rx/9.6 Tx 57.6 Kbps Trials GSM GPRS Technologies Start 38.4 Rx/9.6 Tx Limited Deployment EDGE Trials Start 384 Kbps Packet General Deployment

22. WLAN Applications • The original application is to allow office (or home) networking, with file, printer and internet access sharing. • Industrial applications, networking factory or hospital devices without wires in the way. • The emerging application is public access to the Internet

23. Early Wireless LAN Technologies • Proprietary schemes were developed in the early 1990s to extend the advantages of LANs without running wires. • After early work on radio technology in the TIA, the work moved from to the P802 committee of the IEEE • HiperLAN was developed in ETSI, with support for voice and other isochronous services as well as packets.

24. IEEE 802.11 Progress • IEEE generated 802.11, using the 2.4GHz ISM band, first at rates of 1 and 2 Mbps. • “HomeRF” was a short lived attempt to cost reduce 802.11. • 802.11a was standardized for rates up to 54Mbps using the 5 GHz band. • 802.11b was standardized for 11Mbps on the original 2.4GHz band. • 802.11g is in development, to add rates up to 54Mbps in the 2.4GHz band.

25. Local-Area Wireless Summary Local Area Network 1999 2000 2001 2002 2003 Technology Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 802.11 (FHSS) 2.4 GHz 1 Mbps Freq. Hopped Spread Spectrum 802.11 (DSSS) 2.4 GHz 1 or 2 Mbps Direct Sequence Spread Spectrum Hiperlan Initial 23.5 Mbps Shipments High Performance Radio LAN P802.11b (DSSS) 2.4 GHz Initial 11 Mbps Shipments Direct Sequence Spread Spectrum Final Specification Initial Mobile P802.11a 5 GHz Shipments Specifications 54 Mbps Approved Direct Sequence Spread Spectrum

26. Short range wireless: IrDA • Early work centered on InfraRed, given the availability of IR used in remote controls. • InfraRed Data Association developed specifications: • Serial port emulation at 115.2kbps • Upgrade to 4Mbps • It is fast, directional, and depends on unobstructed line of sight. • This is widely supported in PDAs, cameras and some cell phones

27. Short range radio wireless • The cell phone manufacturers found that attaching serial cables to cell phones was cumbersome and consumed a lot of pins. • Being radio experts, they looked for a convenient radio-based solution. • Ericsson, Nokia and other interested manufacturers formed the Bluetooth™ Special Interest Group.

28. Bluetooth Wireless Technology • The prospect of short ranged radio to replace cables attracted a lot of companies with a variety of applications. • The Bluetooth Specifications support a number of Profiles: sets of specifications on how the applications should use the air interface. • Several speakers will address Bluetooth technical issues today in detail.

29. Primary Bluetooth Applications • Cable replacement: • Serial modem access to a DTE • Wireless Headsets • Data exchange between personal devices • OBEX • Ad Hoc networking amongst personal devices • Internet Access • Other device access: • Printers, speakers, etc

30. Personal Area Wireless Local Area Network 1999 2000 2001 2002 2003 Technology Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 IrDA 4Mbps Computer Integrated Products Initial Shipments Bluetooth Integrated Handsets 721 Kbps PC Card and CF Module

31. Common Wireless Trends • IP networks • Always connected • Increased bandwidth • Convenience • Moving from vertical market to horizontal markets • Moving from proprietary to standards based • Proliferation of smart devices • New scenarios enabled • Outsourcing • Adhoc networks

32. Desktops, Notebooks TVs, games Books, tablets, handheld PCs Phones, PagersPC companions Ad Hoc Networks Many diverse devices to be connected

33. A Connected Home 1394 STB IrDA 802.11 Ethernet/1394b Internet Bluetooth PLC xDSL Cable Satellite POTS, ISDN Phone Residential Gateway

34. A Connected Small Office Phone Small Business Server 802.11 Bluetooth Internet T1, T3, … Ethernet Edge Server

35. Enterprise GPRS GPRS • Information at your fingertips • At meetings, in the office, on the road • Reliable, secure, multimedia LAN IrDA GPRS Bluetooth Internet Web Server 802.11 T1, T3, … Ethernet Proxy Server

36. An ISP Connected Public Space • Discovery of proximity services (flight schedules at airport, mall directories, …) Bluetooth Phone GPRS IrDA Internet Web Server 802.11 T1, T3, … Ethernet Proxy Server

37. Wireless Architecture Requirements • “Just works” • Always connected • Unified transport: IP • Mobility • Unified security model • Adhoc • QoS • Performance

38. Designer Issues Addressed Today • What is Bluetooth technology? • Tim Reilly, Stonestreet One, next speaker • What are all the Bluetooth Protocols? • Andy Glass, Microsoft • How do I deal with antennas? • Kerry Greer, Skycross • How do WLANs work, how to test them? • Todd Stockert, Agilent • How do I get my product tested and certified? • Karsten Beckman, Rohde & Schwartz

39. Web References • http://www.wow-com.com/ for cellular • http://www.bluetooth.com • http://www.wi-fi.com for 802.11 • http://www.irda.org • http://www.stonestreet.com • http://www.microsoft.com/hwdev/wireless • http://www.microsoft.com/hwdev/bluetooth • http://www.skycross.com • http://www.rohde-schwarz.com