電子信息工程外文翻譯--綜合布線(xiàn)的未來(lái)（適用于畢業(yè)論文外文翻譯+中英文對(duì)照）-文庫(kù)吧
2025-01-02 02:23 本頁(yè)面
【正文】 dia?Future directionsAs far as we can see into the future, mercial information transfer will consist of both lowspeed and highspeed requirements. Applications such as voice, building automation systems, alarms, and security systems will still use low bandwidths. Voice information may change from central office exchange delivery to intelligent peripheral, but bandwidth requirements won39。t increase by a large amount. The data packets, with which the voice packets ride, will increase bandwidth requirements. The requirements to transport large amounts of information in shorter and shorter periods of time are changing, and will continue to change. Applications such as graphical data (both schematic and pictorial), scientific modeling, desktop videoconferencing, multitiered relational databases and other dataintensive information will drive up the bandwidth requirements.If history is any predictor of the future, we will see information transfer speeds increase at least one order of magnitude per decade. We have seen local area network speeds, on UTP, increase from 10 Mb/s in the mid 1980s to 100 Mb/s in the mid 1990s then to 1 Gb/s in the late 1990s. Today, standards are being written for 10 Gb/s. Where will we be in 2010 or 2020? Microsoft39。s Bill Gates is quoted as saying, We will have infinite bandwidth in a decade39。s time. Lawrence Berkeley Laboratory (Berkeley, CA) has projected its throughput needs for 2020 to be 40 Gb/s. What will be its media of choice: UTP, coaxial, shielded twistedpair, optical fiber, or wireless technology?The two major properties required for any cabling system to be the system of choice are its performance and its relative economics (which include ease of installation). Undoubtedly, fiber and shielded twistedpair (STP) systems are quite robust and provide greater signal headroom than UTP. However, they lag far behind UTP in customer acceptance for today39。s applications. But will UTP and other media systems provide the bandwidth for future applications? Will they provide economical solutions? Let39。s look at the proposed solutions for future requirements. Unshielded twistedpairCurrently, standards are being solidified to extend the transmission characterization of UTP to 250 MHz. Many manufacturers are advertising the availability of products that exceed yettoberatified specifications. Many technical hurdles have to be solved before a Category 6 standard is published. However, it is reasonable to expect that these hurdles both technical and political will be resolved. It is generally recognized that UTP has not yet been pushed to its theoretical limits. The question yet remains as to the continued viability of UTP as information speeds increase.If future technology does not improve the efficiency of bandwidth utilization, then the cost of the electronics, installation detail, and the testing requirements may diminish UTP39。s benefits relative to other potential options. It should be noted that currently, there are no plans to develop a standard copper solution for 10 Gigabit Ethernet.Shielded twistedpair Shielded twistedpair is currently characterized at frequencies to 300 MHz. The International Organization for Standardization and International Electrotechnical Commission (I
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