her node believes is in use. Then node A party" introduction is not shown. The certificate will propose which frequency block to use for traffic for authority could be the third party, or another authorized the next time slot, at what data rate, and in what user could add a new user with some set of authority. The waveform. CR will learn and adapt to the new set of users and to the From this point forward, the nodes will have sufficient changing biometric measures of a user. For example, if connectivity to track changes in spectral activity and to a user gets a cold, his voice may change, but the corre- stay synchronized for which frequencies to use next. lation between the "new voice" and the fingerprint Cognitive radio: The technologies required CHAPTER 2.4b scanner is still strong, and the CR may choose to tem- 2.4b.7.2 Manufacture of new products porarily update the voice print template. Many products have new sensors and actuators in them. Cellular telephone handsets are a high-volume, highly 2.4b.7 Timeline for CRs competitive product area, from which innovation is driven by these characteristics. In fact, a large fraction of CR development will be a spiral effort. The when, where, new cell phones have an integrated digital camera. These how, and who of this development are discussed below: are manually operated today, but CR applications may When: Currently, several CR initiatives are under way. take advantage of this sensor for more "cognitive" oper- ation modes. Progress is evident every day, and more and more sophisticated demonstrations are imminent. Some of Chemical sensors have been integrated to some cell these demonstrations will include better policy con- phone models. The purpose of the chemical sensors is to formance characteristics. report on important "problems" such as "bad breath" and Where: The FCC and NTIA are currently discussing "blood alcohol level." This is a manually operated device, a test band for CR. They are suggesting a 10 MHz but future applications may be more autonomous. exper