e put into sleep mode and woken up when needed within 20 milliseconds, for example to support dead reckoning when a GPS signal is lost. MEMS-based devices measure the angular rate of change using principles described by Gaspard G de Coriolis in 1835 and now known as the Coriolis effect. The diagram in Figure 5.4 from an Analogue Dialogue article¹³ shows that as a person or object moves out towards the edge of a rotating platform the speed increases relative to the ground, as shown by the longer blue arrow. 13 http://www.analogue.com/library/analogDialogue/ Wireless User Hardware Embedded FIFO pitch LGG4200DH gyroscope Figure 5.3 STMicroelectronics MEMS-based module. Reproduced with permission of STMicro- electronics. Figure 5.4 Coriolis acceleration. Reproduced with permission of Analog Devices. Making Telecoms Work INNER FRAME RESONATING MASS MASS DRIVE DIRECTION SPRINGS CORIOLIS SENSE FINGERS Figure 5.5 Springs and mechanical structure. Reproduced with permission of Analog Devices. The movement is captured by an arrangement of sensors, as shown in the springs and roundabouts diagram, see Figure 5.5 above. Integrating microsensing with GPS based macrosensing is covered in more detail in Chapter 16. 5.2.3 Imaging Capabilities Imaging includes imaging capture through a camera or multiple cameras and image display. Camera functionality is also covered in Chapter 7. For the moment we want to just study technology and business impact of display technologies. First, one that didn't make it. In Chapter 5 of 3G Handset and Network Design we featured a miniaturised thin cathode ray tube based on an array of microscopic cathodes from a company called Candescent. The thin CRT had a number of advantages over liquid crystal displays including 24-bit colour resolution, high luminance, wide-angle viewing and a response time of 5 milliseconds that compared with 25 milliseconds for contemporary LCDs. The company announced plans in 1998 to invest $450 million in a US-based manufacturing plant in association with Sony. Candescent 