Microwave Engineering Europe - May 2008 - (Page 30)

30 UWB the memory card until just 5 percent of its battery, or 150 mWh, remains. In such a situation, it is possible to examine how the DSC would behave using three technologies: UWB, 802.11 and Bluetooth. — UWB. Assume for UWB a 100-Mbit/s average data transfer rate. Note that this assumes a 400-Mbit/s PHY rate active half the time. Assume an average power consumption of 250 mW during active mode. Bluetooth and 802.11 technologies would consume 18 percent and 7.6 percent of their batteries, respectively, to transfer 4 Gbytes of data. In contrast, UWB would consume a mere 0.75 percent of its battery. Transmitting 4 Gbytes of data over the air would take UWB 328 seconds (4096/12.5), or 5.5 minutes. Based on a 250-mW average power consumption, the data transfer would consume 22.7 mWh, less than 0.75 percent of the camera’s battery. — 802.11. For a Wi-Fi implementation, assume a 20-Mbit/s average data transfer rate and an average 500-mW active-mode power consumption. Transmitting 4 Gbytes of data using 802.11 would take 1638 seconds (4096/2.5), or 27 minutes. Based on a 500-mW average power consumption, the data transfer would Bluetooth and 802.11 technologies would consume 18 percent and 7.6 percent of their batteries, respectively, to transfer 4 Gbytes of data. In contrast, UWB would consume a mere 0.75 percent of its battery. consume 228 mWh, or approximately 7.6 percent of the camera’s battery. — Bluetooth. For a Bluetooth implementation, assume a 1-Mbit/s data transfer rate and an average of 60 mW of active-mode power consumption. Transmitting 4 Gbytes of data with Bluetooth would take 32,768 seconds (4096/0.125), or nine hours. Based on 60-mW average power consumption, the data transfer would consume 546 mWh, or roughly 18 percent of the camera’s battery. The results of this usage scenario played out with the three different technologies makes it is clear to see that UWB consumes signiﬁcantly less power. By effectively addressing the challenges in these areas and capitalizing on UWB/Wireless USB’s inherently low power use, designers can successfully reduce power consumption and maximize throughput, both of which are essential to driving the next phase of UWB/ Wireless USB in mobile devices. About the author Gadi Shor, chief technology ofﬁcer at Wisair, has more than 18 years of hands-on experience in researching, simulating and implementing wireless communication systems. Shor holds MSc and BSc degrees in electrical engineering from Tel Aviv University. www.mwee.com/207401106 WiMax catches second test wave By Richard A. Quinnell, EE Times Even as Worldwide Interoperability for Microwave Access (WiMax) technology begins riding its ﬁrst wave of deployment, secondgeneration equipment design is entering the water. WiMax developers are targeting what they call Wave 2 development, which aims to increase security and performance in ﬁxed and mobile applications. Test equipment vendors are releasing new and upgraded equipment that addresses Wave 2 test needs throughout the development cycle, from design through production to ﬁeld installation. WiMax is just about ready to enter the wireless data communications marketplac — and make a splash doing so. According to estimates from an independent research study (due out this month) that the WiMax Forum commissioned, more than 133 million WiMax users will surface across the globe in the next four years. Forecasts also predict at least 250 service providers emerg- ing in 110 countries worldwide, mostly in the Asia-Paciﬁc region and the Americas. Such numbers indicate ample opportunity for developers creating chips, modules, enduser devices and basestation equipment. Fixed and mobile Two types of WiMax systems are involved in this opportunity, and they have different system requirements. Fixed WiMax (IEEE 802.16-2004) provides line-of-sight connections between the basestation and customer premises over a range of 30 miles, providing a wireless alternative to cable and DSL. Mobile WiMax (IEEE 802.16e-2005) uses additional modulation schemes to provide improved performance within a 10-mile radius for non-line-of-sight applications in which the user may be mobile. The WiMax Forum’s study indicates that ﬁxed and mobile WiMax will split the user market, with 70 percent going mobile. The forum anticipates that the ﬁrst certiﬁed mobile WiMax user products will become available this quarter WiMax is still in early development, however, and design opportunities remain. Both the ﬁxed WiMax and mobile WiMax communities are actively pursuing technology enhancements to support Wave 2, for which test equipment is becoming available. For ﬁxed WiMax, Wave 2 refers to protocol enhancements that provide quality-ofservice controls to support real-time applications such as voice-over-IP (VoIP), streaming media and gaming. It also includes security enhancements such as adoption of the enhanced encryption standard (AES). For mobile WiMax, Wave 2 further includes support for system designs that use multipleinput, multiple-output (MIMO) antennas to increase performance through active beam forming and increased spectral efﬁciency. The enhancements of WiMax Wave 2 have created new test needs for developers working Microwave Engineering Europe ● May 2008 ● www.mwee.com http://www.mwee.com/207401106 http://www.mwee.com

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Microwave Engineering Europe - May 2008 News Contents Comment Cover Feature: How to Succeed as a GaAs Foundry Wireless Networking: Wireless Coverage Where Everybody WINS Wireless Networking: Achieving Good Coexistence in the 2.4 GHz ISM Band GPS and Satellite: GPS developments: Galileo Moves Forward with Successful Giove-B Satellite Launch — Broadcom Targets AGPS in Mobile Phones and Devices Raising the Bar for the Radio: Making 802.11n Work Reducing Power Consumption in Ultrawideband Chips WiMax Catches Second Test Wave Products Calendar

Microwave Engineering Europe - May 2008

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