Broadband WLAN and UWB Technologies

Transcription

1 Broadband WLAN and UWB Technologies EC Workshop on "Advanced Wireless Technologies: Implications for Spectrum Management" Brussels, 10 October, 2003 Walter Hirt IBM Zurich Research Laboratory, CH-8803 Rüschlikon, Switzerland

2 Contents Zurich Research Laboratory Broadband Wireless LAN Technologies Status of Standards and Technology Ultra-Wideband (UWB) Radio Technology Characterization and Application Areas Evolution of Short-Range Radio Technologies Enabling Pervasive Connectivity and Co-existence Issues Implications on Spectrum Management Technology Impact on Regulatory Process 2

3 Broadband Wireless LAN Technologies 1 Status of Standards Wireless LAN (WLAN) standards mainly developed by IEEE (802.11) and ETSI (HL) Currently, the most popular WLAN standards is b as specified by IEEE in 1999 for data rates up to 11 Mbit/s (~6 Mbit/s real throughput) in the 2.4 GHz ISM band b is widely supported by the Wireless Ethernet Compatibility Alliance (WECA) which strives to achieve guaranteed interoperability of b enabled devices The newer IEEE a standard provides data rates of up to 54 Mbit/s (~30 Mbit/s real throughput) within the 5 GHz ISM band Recently, an alternate standard called g was approved offering also up to 54 Mbit/s nominal data rate and operating in the 2.4 GHz ISM band (as b and BT) Earlier, ETSI developed other WLAN standards, e.g., RLAN (RadioLAN) and HiperLAN 1 and 2, operating also in the 2.4 GHz and 5 GHz ISM bands, respectively IEEE a devices experienced compatibility issues in Europe Until recently, operation in the 5 GHz range was either limited or forbidden in most of Europe parts of the bands are used for radar and other services (e.g., EESS) ETSI required a specific set of new features giving rise to the recently approved IEEE h standard extension (amendment to a PHY and MAC specifications) Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) 3

4 Broadband Wireless LAN Technologies 2 Status of Technology (Reference: R. Merritt, EE Times, Aug. 26, 2003) Prices for chips and devices are dropping rapidly and the number of public wireless LAN hot-spots continues to grow fast Average selling prices for Wi-Fi chips will be cut in half perhaps to ~$8 this year ~$4 next year and possibly to as little as ~$2 in 2006 (based on all CMOS chips?) There are ~5 000 Wi-Fi hotspots in the US today, however, this number must double in areas such as airports, hotels and conference centers to reach a critical mass Industry is making efforts to create a hot-spot-in-a-box to provide access points and everything else needed for its operation for well under $200 (new: WLAN switches) VoIP calls over WLAN are now possible this capability spreads faster than anticipated Support for x (to be) integrated in Intel s chip sets for Centrino notebooks Whether will be integrated in mobile phones is currently much debated many predict that Wi-Fi will become a standard component of future mobile phones A market shift took recently place among the service providers many moved away from flatly refusing WLAN technology to seriously considering and then deploying it Providers now offer broadband WLAN services to enable high-rate data services while lowering their infrastructure costs (3G!) and the effective charges for their customers 4

5 Broadband Wireless LAN Technologies 3 Example of Technology Leap Decision makers on Spectrum Management and Radio Service Regulations will be more and more challenged to anticipate future (!) technological developments New technological advancements could eventually obsolete regulations or they could lead to attempts of interpreting the rules in a way not foreseen by the regulator This challenge exists particularly for the license-free short-range radio services Example Source: 5

6 Contents Zurich Research Laboratory Broadband Wireless LAN Technologies Status of Standards and Technology Ultra-Wideband (UWB) Radio Technology Characterization and Application Areas Evolution of Short-Range Radio Technologies Enabling Pervasive Connectivity and Co-existence Issues Implications on Spectrum Management Technology Impact on Regulatory Process 6

7 What is Ultra-Wideband (UWB) Radio? System Comparison by Spectral Bandwidth Power Spectral Density [W/Hz] SOURCE: Multispectral Solutions Typical Pulsed UWB Signal Note Drawing not to scale ns FCC/Part 15 Limit Conventional Carrier Modulation Direct Sequence Spread Spectrum Ultra-Wideband (UWB) Source: IBM Zurich Research Lab Bandwidth [Hz] G SM -900 IS -5 4 IS -9 5 AMPS GSM-1.8 DECT GSM-1.9 IM T b Bluetooth HomeRF Total Available Bandwidth: 7.5 GHz IEEE a ETSI Hiperlan A R IB M M A C Ultra-W ideband (UW B) (10.6) Source: IBM Research Frequency in G Hz 7

8 UWB Emission Limits Example FCC/Part 15 Outdoor Scenarios (Handheld Devices) 75 nw / MHz / MHz B MAX = 7.5 GHz EIRP MAX = mw EIRP = Effective Isotropic Radiated Power GPS Bands GHz ISM Bands (e.g., IEEE802.11a) Note FCC regulations distinguish for the unwanted emission limit between indoor and outdoor applications; the indoor limit for unwanted emissions is 51.3 dbm/mhz 8

9 Standardization of UWB Radio Systems Complementary Application Areas Low-Rate Data and/or Positioning Applications IEEE a Channel Capacity or Cutoff Rate ~ [Mb/s] UWB Cutoff Rate: R o BP-2-PAM / 256-PPM BP-2-PAM / 64-PPM BP-32-PAM / 1-PPM BP-2-PAM / 1-PPM: N = 1 BT2 BP-2-PAM / 1-PPM: BP-2-PAM / 1-PPM: Free Space AWGN Channel Future UWB and N =10 N =100 Channel Capacity: C UWB = 6.85 GHz C Existing WAN/LAN DG T T f F PRF = 20 Mp/s = 75 nw/mhz B = 7500 MHz B = 1500 MHz = 1 Rx-NF = 3 db High-Rate BP = 1 PBi-Polar M = 10 Data 8 Applications P = 10 M Systems IBM modified after Intel G R IEEE a Source: IBM Zurich Research Laboratory Link Distance [m] 9

10 Application Potential of UWB Radio Technology High Data Rate (HDR) and Low Data Rate (LDR) Usage Scenarios Camcorder PDA Audio Monitor Gateway Printer DVD Desktop Computer TV Laptop Computer Digital Camera Hot-spot Wireless Personal Area Network (WPAN) Wireless Bridge Wide Area Cellular Network Internet Intelligent Wireless Area Network (IWAN) Wireless Body Area Network (WBAN) Wide Area Cellular Network Position Sensor (Alarms, Remote Control Wireless Bridge Position Sensor Home Controller Temperature Position Sensor Sensor Motion Sensor Light Sensor Position Sensor Position Sensor Internet Access Fix line Opt. 3G core network Opt. Sensor, Positioning, and Identification Network (SPIN) PDA Access Box PDA UWB connection Ad hoc connection option PDA PDA Outdoor Peer-to-Peer Network (OPPN) High Data Rate Data Exchange (Gaming) Reference D. Porcino and W. Hirt, Ultra-Wideband Radio Technology: Potential and Challenges Ahead, IEEE Commun. Mag., July 2003, pp

11 Advanced UWB Radio Systems Research Multiple-Input/Multiple-Output (MIMO) Channel Properties Reference M. Weisenhorn and W. Hirt, Performance of binary antipodal signaling over the indoor UWB MIMO channel, in Proc. IEEE 2003 Int. Conf. Commun. (ICC 2003), May 11 15, 2003, Anchorage, AK, USA, paper CT19-2. UWB MIMO System Space-Time Correlation (B = 7.5 GHz) Impulse Response Tx Tx M = 2 N = 4 Rx MLD Tx-Antenna Distance [cm] Time [ns] Time [ns] 11

12 Advanced UWB Radio Systems Research Multiple-Input/Single-Output (MISO) Systems Reference M. Weisenhorn and W. Hirt, Performance of binary antipodal signaling over the indoor UWB MIMO channel, in Proc. IEEE 2003 Int. Conf. Commun. (ICC 2003), May 11 15, 2003, Anchorage, AK, USA, paper CT19-2. UWB MISO System MISO Performance Tx Impulse Response Tx Tx Tx Time [ns] Rx M = 4 N = 1 Symbol-Vector Error Probability y UWB UWB, B=7.5 GHz, M=1, N=1 UWB, B=7.5 GHz, M=2, N=1 UWB, B=7.5 GHz, M=4, N=1 UWB, B=500 MHz, M=1, N=1 UWB, B=500 MHz, M=2, N=1 UWB, B=500 MHz, M=4, N=1 Rayleigh flat fading, M=1, N=1 Rayleigh flat fading, M=2, N=1 Rayleigh flat fading, M=4, N= x SNR [db] Rayleigh (narrowband) B = 7.5 GHz 500 MHz 12

13 Contents Zurich Research Laboratory Broadband Wireless LAN Technologies Status of Standards and Technology Ultra-Wideband (UWB) Radio Technology Characterization and Application Areas Evolution of Short-Range Radio Technologies Enabling Pervasive Connectivity and Co-existence Issues Implications on Spectrum Management Technology Impact on Regulatory Process 13

14 Evolution of Short-Range Radio Technologies 1 Enabling Pervasive Connectivity Technology Trend Impact of Moore s Law on radio technology will greatly reduce power needs, form factors and costs All-CMOS (Silicon) Radio Emergence of two basic radio architectures Highly configurable (i.e. software defined ) multi-standard radios (MSR) providing all types of computing platforms with wireless ports for anywhere, anytime connection Very low-power consuming single-standard radios (SSR) for lower data rates and RFID Advancements in Short-Range Radio Technologies Impact Universal wireless ports enabled by MSRs in all types of computing platforms enable the user to experience true pervasive connectivity Example Portable platform always maintains the fastest, most economical and secure link Very low-power consuming SSRs enable many new applications Example Large-scale deployment of wireless smart sensor and actuator networks (e.g., in homes or industrial/commercial environments) ~Today MEMS AFE BB DSP Near Future MSR: Data Concentrator SSR-MSR: Control Point SSR: Sensor or Actuator Multi- or Single Standard Radio (MSR or SSR) System-on-Chip or Processor Far Future Link to Network Infrastructure Source: IBM modified after Intel Example: Meshed Sensor, RFID and Control Networks Source: IBM 14

15 Evolution of Short-Range Radio Technologies 2 Is UWB the Solution for a Difficult Wireless Integration Problem? Example IBM s Linux Watch (WatchPad) includes wireless devices (Bluetooth and IrDA) for communication with notebooks, PDAs and cell phones designers have been challenged by the limited amount of real estate inside wristwatches for the processors, memory and other components limited battery power has also been a constraint! A sensible performance measure of a system ( M ) is the ratio between the system s spatial capacity (C S ) and product of [battery] power consumption (P DC ), system cost (P $ ) and volumetric size (V ): Bluetooth UWB? Main Board C ( b/ s) m M P P V W m 2 S =, 3 DC $ $ is this the right case for UWB? Size 65 x 46 x 16 mm Weight 43 g w/o band Communications CPU Memory Bluetooth (V1.1w/voice) UWB? IrDA (V1.2) UART (Cradle) Low-Power 32-bit DRAM 8MB, Flash 16MB OS Linux V

16 Evolution of Short-Range Radio Technologies 3 Interference Mitigation and Co-existence Issues Investigations of Interference and Co-existence Issues related to UWB radio devices are currently conducted with some urgency (e.g., within EC/IST-FP5 projects, IEEE) Establish a realistic data base as input to the regulatory process (CEPT, ETSI) based on the EC s recently issued UWB Standardization Mandate (DG ENTR M/329) Interference and co-existence issues arise in two ways: i) UWB devices as potential interference sources and ii) UWB receivers as victims of other radio signal sources Possible Mitigation Technologies TPC (Transmit Power Control) DFS 1) (Dynamic Frequency Selection) e.g.,fig. Flexible (mono-) pulse shape signaling Multi-band signaling (e.g., frequency hopping) a 5 GHz band Dynamic Frequency Selection *) DRS (Data Rate Scaling) 1) (a key strength of UWB!) Fall-back modes less data rate less RF power to maintain same performance Dedicated vs. Interacting Protocols (e.g., MAC level or across different layers) Potential Challenge Co-location of WLAN, BT and UWB sub-systems in a cell phone 1) DFS and DRS are also concepts of Reconfigurable Radios *) Concern is interference from 5 GHz WLAN to UWB Rx 16

17 Contents Zurich Research Laboratory Broadband Wireless LAN Technologies Status of Standards and Technology Ultra-Wideband (UWB) Radio Technology Characterization and Application Areas Evolution of Short-Range Radio Technologies Enabling Pervasive Connectivity and Co-existence Issues Implications on Spectrum Management Technology Impact on Regulatory Process 17

18 Implications on Spectrum Management 1 One-way Regional Regulation Standards Deployment is old thinking! Regulatory Challenges vs. Industry Needs Regulatory processes must take a global view while being challenged i) by regional issues and ii) a need to anticipate capabilities and applications of future (!) technologies Need for a common understanding among regulators, industry and standards bodies to facilitate (flexible) spectrum harmonization and industry standards on a global scale Complexity and number of features & functions in future devices will keep growing Economic solutions can only be realized with the prospect for a global (mass) market which can be best facilitated with globally compatible spectrum regulations and standards Spectrum Management Broadband WLAN Until WRC 2003, the 5 GHz bands in Europe, USA and Japan were very differently assigned and used UWB radio Requires a novel approach to spectrum management to enable the needed globally compatible framework Amended Initial Regulation Regulation Deployment Standards Amended Standards 18

19 Implications on Spectrum Management 2 Enhanced Regulatory Process (e.g., Singapore s Approach to UWB Regulation) IDA s UWB TESTS & MEASUREMENTS Ambient Noise Study Interference to Existing Systems Aggregate Effect of Multiple Devices 1) 1) Artificial worst-case (!) models have been proposed in the past but none has been verified in the field thus far Ultra-wideband Friendly Zone (UFZ) UFZ At IDA's 4th Technology Roadmap Symposium (26 Nov., 2002), UWB was identified as a potentially disruptive communication technology tidal wave that is expected to significantly impact the Infocomm Landscape. To encourage experimentation and facilitate investigation, IDA permits UWB transmissions at 6dB above the FCC Part 15 level ( 41.3 dbm/mhz) from 2.2 GHz to 10.6 GHz. Note For more information on Singapore's UWB Programme, refer to IDA Programmes" on IDA s website: (IDA: Infocomm Development Authority of Singapore) 19

20 Thank You! Q&A s? Zurich Research Laboratory Technology is no barrier old thinking is. William E. Kennard, Chairman FCC The Hill, February 2,