6.Current and Future Challenges for UWB Technology

There are challenges to UWB technology from different directions that can threaten its current and future success. These includes:

• design and Regulation challenges
  
• Challenge due to lack of a common standard for everybody
• Competition from other standards

Let us look more closely to these challenges one by one

a. Design and regulation Challenges
The transmitter power level of UWB signals is strictly limited in order for UWB devices to coexist peacefully with other wireless systems. Such strict power limitation poses significant challenges when designing UWB systems. One major challenge is to achieve the performance desired at an adequate transmission range using limited transmitter power. other challenge is to design UWB waveforms that efficiently utilize the band width and power allowed by the FCC spectral mask. Moreover, to ensure that the transmitter power level satisfies the spectral mask, adequate characterization and optimization of transmission techniques ( e.g., adaptive power control, duty cycle optimization) may be required.
Meeting the requirement of the regulation set for UWB by the FCC through design was and is not simple. In the United states, the then-MBOA (now WiMedia) proposal in particular faced strong FCC scurinity. In fact, the group did not receive FCC approval for their technology until March 2005, and the first chips based on the standard were not approved until August 2005. The delay was the result of an FCC requirement that UWB systems undergo strict testing. Though the WiMedia specification hops frequencies in order to minimize interferences, the FCC ordered frequency hopping turned off during testing, thus allowing the FCC to increase its susceptibility to interference . Further, data transmission would need to be turned off. These factors would have made it likely that emissions and interference would appear higher than under actual operating conditions. Although the UWB Forum's proposal was more readily approved by the FCC, UWB's frequency overlap with crucial wireless technologies such as GPS systems and cell phones has caused some concern.
More issues on the design challenges can be found here

b. Lack of a common standard
Even though the WiMedia Alliance was able to get its technology standardized through the European Standardization organization Ecma International as well as the International Organization for standardization (IOS) , the challenge is not yet over. This issue is discussed in section 4. This lack of a common standard is usually referred to as one of the main reasons as to why the UWB technology has not shown enough progress as anticipated in the early 2000's.

c. Competition From Other Standards
UWB also faces competition from other high-speed wireless standards, particularly from the next generation wireless local area network (WLAN) standard 802.11n. The Wi-Fi Alliance is certifying draft 2.0 products before the final 802.11n standard has been ratified by the IEEE. Final ratification is expected in July2008. Nevertheless, users are already enjoying the 100Mbps+ performance promised by this standard. The characteristics of 802.11n standard and the UWB technology is already compared and discussed in section 5.
Though 802.11n is considered the most challenging standard to UWB for the WPAN application, there are other technologies emerging specially in a Wireless Video Home application. Amimon's WHDI and Pulse~Link's CWave are two of the currently emerging wireless technologies and may dominate the vedio distribution marketplace. Both were designed and optimized for video so they are fast, simple, and cheap-something that the consumer electronics market appreciates.
More information on the challenges from Amimon's WHDI and CWave can be found here

How about with Bluetooth?
Despite the likely competition from future and current wireless technologies, UWB could easly be incorporated to work with existing standards. Since Bluetooth and UWB have similar data transfer ranges, concern initially rose over whether UWB would eclipse the technology, particularly since it could perform the same task at dramatically increased speeds. Typically used to wirelessly link computers to peripherals such as keyboards and headsets, Bluetooth operates at approximately 1/100 th of potential UWB speed. Perhaps recognizing the potential downfall of their technology, the group responsible for developing and popularizing Bluetooth decided to link themselves to UWB proponents. Known as the Bluetooth special Interest group, the coalition is now working with the WiMedia Alliance to develop a high-speed version of Bluetooth. This quicker version of Bluetooth uses the WiMedia standard of OFDM to produce speeds up to 480Mb/s over a range of a few meters.