ch access devices. remote locales. Ubiquity More applications Not only is network coverage increasing, but the number The increased availability of network coverage and of wireless devices is growing at a high rate. The reduced wireless devices, and advances in associated electronics size and price of radios makes it feasible to add wireless technologies, makes new applications viable. Mobile capability to almost any device. Advances in supporting voice and mobile text messaging have been wildly pop- technologies, as well as wireless technologies, make ular. The marriage of cameras and wireless opens the radios viable where they never have been before. door for some form of photo messaging. Cellular carriers (at the behest of the FCC, for safety reasons) are Battery power density continues to improve, reduc- deploying location determination capabilities, some using ing the size and increasing the utility of portable the global positioning system (GPS). Once these capa- devices. Viable alternate power sources are on the bilities are in place, a range of new applications beyond horizon. public safety will be available. Many see electronic User-interface advances (e.g., voice recognition, new gaming as a huge growth area, just now in its infancy. display technologies) add convenience and poten- tially open the door for new applications. Integrated circuits continue to double their capabil- Conclusion ities every year or two, allowing designers to pack more functions into ever-smaller packages. Newer The rich history of progress in wireless and RF commu- semiconductor technologies and manufacturing pro- nication has given us an array of technologies suited to cesses provide increased efficiency. a wide range of applications. We are in a time of explosive Processing techniques, such as software-defined growth in wireless technology, as evidenced by the ad- radio, scripting and presentation languages (Java 2 vances described throughout this book. Coupled with the CHAPTER 1.0 Introduction Internet content that is now av