Intel ® Technology Journal Intel ® Centrino ™ Mobile Technology Mobile Pc Platforms Enabled with Intel ® Centrino ™ Mobile Technology Mobile Pc Platforms Enabled with Intel ® Centrino ™ Mobile Technology

Mobile PC platforms enabled with Intel CentrinoTM mobile technology incorporate innovative technologies to significantly increase the mobility of notebook PCs. In this paper, we describe the following innovations: • How to reduce interference between wireless communication technologies using the Intel Wireless Coexistence System (Intel WCS). • Two techniques for significantly extending average platform battery life. • Simple thermal solutions for thinner and lighter form factors. Finally, we outline a comprehensive platform-level validation process that helps deliver a stable platform with Intel quality. INTRODUCTION Platforms enabled with Intel Centrino mobile technology incorporate innovative technologies to significantly increase the mobility of notebook PCs. This paper describes innovations in reducing interference between wireless communication technologies, extending average platform battery life, and in driving a thermal solution for thinner and lighter form factors.  Intel and Intel Centrino are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. When multiple wireless technologies such as Bluetooth Wireless LAN, and Wireless WAN are embedded in the same mobile system, the risk of interference between these radio frequency (RF) technologies greatly increases because of their close proximity to each other. In this paper we discuss general technical RF challenges for mobile platforms and describe innovative techniques used on platforms enabled with Intel Centrino mobile technology. These techniques mitigate interference by using the Intel Wireless Coexistence System (Intel WCS). We also discuss new and advanced platform powermanagement features for improved battery life. Two new techniques are described: asynchronous voltage regulator (VR) control with a power status indicator (PSI), and multiphase Intel Mobile Voltage Positioning (IMVP). Platforms enabled with Intel Centrino mobile technology also incorporate state-of-the-art techniques to enable compact, lightweight thermal solutions in smaller form factor systems. The design includes an efficient remote heat exchanger, an air flow set aside for system cooling, and system venting, that together cool the processor and the system as a whole, using only a single fan. The latest interface materials, heat pipe technology, and fans provide the required performance in a small package. Finally, Intel validation best-known methods (BKMs) are applied to ensure that these platforms deliver optimum ∗ Other names and brands are the property of their respective owners  Intel is a trademark of Intel Corporation or its subsidiaries in the United States and other countries. Intel Technology Journal, Vol. 7, Issue 2, May 2003 Mobile PC Platforms Enabled with Intel CentrinoTM Mobile Technology 7 system performance with multiple wireless technologies operating concurrently within the enterprise as well as when connected to hotspots outside the enterprise. WIRELESS TECHNOLOGIES Platforms enabled with Intel Centrino mobile technology incorporate innovative radio frequency (RF) technologies to significantly increase the mobility of notebook PCs. These technologies include Wireless Personal Area Networking (WPAN), e.g., Bluetooth; Wireless Local Area Networking (WLAN), e.g., 802.11a and 802.11b; and Wireless Wide Area Networking (WWAN), e.g., General Radio Packet Service (GPRS). Integrating multiple wireless technologies greatly enhances connectivity to the enterprise Intranet and the Internet, as well as to peripherals such as PDAs, printers, and headsets. Radio Frequency Challenges in Mobile Notebook PCs When incorporating RF technologies into a digital computing environment such as a notebook PC, traditional system designers are faced with new challenges previously relegated to RF engineers. Antennas must be added for each frequency band. Since notebook PCs generally consist of many metallic components such as framing structures, hard drives, displays, antenna radiation patterns can be greatly distorted. This distortion can potentially cause significant RF performance variations, as the notebook PC’s physical orientation is varied relative to the location of the intended communicating device such as an access point (AP), a peripheral such as a printer, and even another notebook PC. These RF technologies consist of very sensitive receivers and potentially high-power transmitters. When multiple RF technologies are embedded (co-existent) in the same notebook PC, the risk of interference between these technologies is greatly increased as the transmitters of one radio can couple with the sensitive receivers of another radio, even if they operate in different frequency bands. Technologies such as Bluetooth and 802.11b have even greater interference risks since they both operate in the same 2.4GHz frequency band. Antenna isolation techniques mitigate some of these interference issues, but with multiple antennas and decreasing form factor sizes, optimal placement of antennas is not always possible. New interference-mitigating technologies are then required. For example, Intel Centrino mobile technology includes the Intel Wireless Coexistence System (Intel WCS), which significantly mitigates the interference between 802.11b and Bluetooth technologies. Intel Wireless Coexistence System While antenna isolation provides some interference mitigation between 802.11b and Bluetooth radios, performance is still impacted to some degree. For example, 802.11b data throughput is degraded by Bluetooth interference, even with 40dB of antenna isolation, as shown by the lower curve in Figure 1. The upper curve shows the ideal throughput when no Bluetooth interference is present. 802.11b Throughput With Bluetooth Interference 0.00 1.00 2.00 3.00 4.00 5.00 6.00 1.00 10.00 100.0