the ability to create short impulse or step functions Union are relatively low, on the order of spurious radia- with rise times on the order of tens or at the most tion limits for conventional unlicensed transmissions. hundreds of picoseconds, and to detect the UWB pulses However, as we have seen, high-processing gains can be that result from their application. High speed integrated achieved with UWB and communication ranges on the circuits can be employed or special circuit elements, order of tens or hundreds of meters at high-data rates can such as tunnel diodes or step recovery diodes, can be be expected. Also, the FCC has indicated its intention to incorporated. monitor the effects of UWB transmissions on other ser- The main FCC regulations pertaining to ultra-wide- vices, once equipment has been put into service in sig- band transmissions are described elsewhere. Conditions nificant quantities, and the agency may be expected to TRANSMITTER PSEUDORANDOM DELAY CODE PULSE SHAPING PULSE TIME GENERATOR NETWORK MODULATOR DATA IN CLOCK RECEIVER BASEBAND MIXER SIGNAL SAMPLE AND INTEGRATOR PROCESSING PSEUDO-RANDOM ACQUISTION DELAY CODE PULSE TIME MODULATOR AND TRACKING CLOCK PULSE GENERATOR Figure 5.2-31 UWB simplified block diagram. Short-range wireless applications and technologies CHAPTER 5.2 modify or make its limits more lenient if interference is consumption for integrated circuits will help, as will found not to be a problem. In any case, the unique sophisticated wake-up protocols as are already built-in to characteristics of UWB are attractive enough to make Bluetooth. Range limitations may have to be dealt with this technology an important part of the offerings for by a greater use of repeaters than common in today's short-range wireless communication in the years systems. Another area where advancements are affecting to come. short-range radio is antennas. Both the use of higher frequencies and new designs are reducing antenna size and eliminating a visual reminder of the difference be- tween wired and wire