Applications
In its current state of development, UWB is aimed at high data rates for personal-area networks, which have an effective operating radius of approximately 10 meters or less. Though similar to the current capabilities of Bluetooth, it uses a very different technology. UWB transmissions trade distance for bandwidth, so the greater the range, the lower the final data rate. Range can be extended up to perhaps a kilometer by using high-gain antennas and reducing performance.
One of UWB’s defining characteristics is that it requires very little electrical power——one source says it uses 0.001% as much power as a cell phone——and thus is virtually undetectable by conventional radios, which see the UWB signal as just very quiet background noise. Thus, a UWB telephone would use so little power that it could remain on for weeks without needing to be recharged. And because it uses all available spectra, UWB may well be cheaper to design and manufacture than conventional radios that require careful tuning to a specific frequency.
A UWB transmitter and receiver must be closely coordinated and synchronized to send and receive pulses with an accuracy of trillionths of a second. The receiver responds only to a familiar pulse sequence. This makes UWB very secure, which explains why it was once used for clandestine communications by military and espionage agencies. UWB's broad frequency range includes the ultralow frequencies the U.S. Navy uses to communicate with submerged submarines.
UWB products will include radar and electronic location and positioning devices in addition to radios. UWB radar can see right through walls, ceilings and floors that would block or reflect other types of radio signals. As an electronic measuring technology, UWB is more accurate than Global Positioning System satellites, and it can be used indoors. The Navy reportedly plans to put UWB markers on almost everything it ships overseas, just to track materiel and keep it from being stolen.
Eventually, UWB networks are expected to run at speeds up to a gigabit per second and therefore should be able to handle all of the phone, television, and Internet traffic for a home or small business.
UWB, Bluetooth and IEEE 802.15.3
Ultrawideband will not replace Bluetooth for short-range communications, because Bluetooth is a complete, end-to-end communications standard, whereas UWB is merely a radio technology that can be used as part of an overall standard. Bluetooth defines how data is managed, formatted and physically carried over a wireless personal-area network (WPAN). However, designers expect that future Bluetooth implementations will be built on top of UWB signals.
802.15.3 is the IEEE standard for a high-data-rate WPAN designed to provide sufficient quality of service for the real-time distribution of content such as video and music. It is ideally suited for a home multimedia wireless network. The original standard uses a traditional carrier-based 2.4-GHz radio as the physical transmission layer.
802.15.3a, a follow-on standard still in the formative stages, will define an alternative 0layer. Current proposals based on UWB will provide more than 110Mbit/sec. at a distance of 10 meters and 480Mbit/sec. at 2 meters.(The End)
超寬帶無線技術
應用
在目前的開發狀態下，UWB旨在提供個人區域網中的高數據傳輸率，它的有效范圍大致在10米或更短一些的半徑內。雖然它與藍牙當前的能力相近，但它采用完全不同的技術。UWB發射是以帶寬換距離，距離越長，最終的數據率就越低。利用高增益天線和降低性能，可以把距離延長到一公里。
UWB的顯著特點之一就是要求極低的電功率——有消息稱它使用的功率只有手機的0.001%，所以常規的無線電設備實際上是檢測不到UWB的，因為它把UWB看成極低的背景噪聲。因此，UWB電話使用極小的功率，不需要充電就可以使用數周。由于UWB使用可資利用的所有頻譜，所以它比設計和制造需要仔細調諧到指定頻率的常規無線電設備更便宜。
UWB發射機和接收機必須緊密配合和同步，以便發送和接收精度為萬億分之一秒的脈沖。接收機只響應熟悉的脈沖序列。這使UWB非常安全，這就解釋了為什么UWB一度由軍方和諜報部門用于秘密通信。UWB寬闊的頻率范圍包括了極低頻率，美國海軍將它用于與水中潛艇的通信。
UWB產品除了無線電外還包括雷達和電子定位設備。UWB雷達可以穿透墻壁、天花板和地板，而其他類型的無線電信號會被這些東西擋住或反射。作為一項電子測量技術，UWB比全球定位系統衛星更精確，它可以在室內使用。有報道稱，美國海軍計劃在運到海外去的幾乎所有東西都裝上UWB標志，以便跟蹤它們，防止被偷。
最終，UWB網絡有望運行在高達每秒千兆位的速度上，因此能處理電話、電視以及家庭和小公司的因特網流量。
UWB、藍牙和 IEEE 802.15.3
超寬帶不會代替用于短距離通信的藍牙，因為藍牙是一個完整的、端到端的通信標準，而UWB只是一種無線電技術，只能作為一個完整標準的一部分。藍牙定義了數據是如何管理和格式化、以及在無線個人區域網上是如何承載的。但是，設計人員希望將來藍牙可基于UWB來實現。
802.15.3是IEEE的高速率WPAN（無線個人區域網）標準，設計旨在為視頻和音樂等內容的實時分發提供足夠的服務質量。它非常適合家庭多媒體無線網絡。最初的標準使用傳統的基于載波的2.4GHz無線電作為物理傳輸層。
802.15.3a是一個后來的標準，還在形成之中，它將定義一個可替代的物理層。最新的建議就是基于UWB，它將提供在10米的距離上超過110兆位/秒和在2米距離上480兆位/秒。這將允許媒體服務器和高分辨率監視器之間的高分辨視頻流，以及服務器和便攜設備之間極快的文件傳輸。（全文完）
文章來源于領測軟件測試網 http://www.kjueaiud.com/
