Summary

Chapter 13: Advanced Laptops and Portable Devices 5Figure 13-1Installing an Infrared DriverThe installation is similar to setting up a LAN connection.IR is a practical, short-range connection solution, but it has some limitations:■■■■IR light cannot penetrate ceilings or walls.IR signals are susceptible to interference and dilution by strong light sources, such asflorescent lighting.Scatter IR devices can connect without line of sight, but data transfer rates are lower,and distances are shorter.IR distances should be 3 feet (1 m) or less when used for computer communications.Describe Cellular WAN TechnologyOriginally, cellular networks were designed for voice communication only. Cellular technologyhas been evolving and now enables the transfer of voice, video, and data simultaneously.It also enables the use of laptops and portable devices remotely. With a cellular WANadapter installed, a laptop user can travel and access the Internet. Common cellular WANcharacteristics include the following:■■■Cellular WAN connections are powerful two-way wireless networks that have beenaround since the late 1970s.Cellular networks operate in one of two ranges: approximately 800 MHz and approximately1900 MHz.Three generations of cellular WAN include voice-only analog, digital, and high-speeddata and voice.Although they are slower than DSL and cable connections, cellular WANs are still fastenough to be classified as a high-speed connection. To connect a laptop to a cellular WAN,