Many schools (used as a synonym for companies and organizations), wireless networking equipment to connect students and teachers who are wired. This type of installation is as an access point. An access point provides two functions: convert the means for transmitting wireless signals from cable and vice versa, and serving customers at once as a hub. It is a popular use of wireless. What is not so well known is the subject of thisItem wireless bridge and our legal obligations. We raise these questions for the first time as a devout Report on research and development of our team IPVS. The results are useful for schools when the school an extension of data networks for various purposes, including video surveillance. Applications are not limited to IPVS.
A radio link is a pair of wireless devices such as the two pillars of the span of aHarbour Bridge. Each wireless device is a radio and antenna. The radio is turned on for the conversion of signals from the cable antenna cable and antenna. The antenna is to increase the signal strength, enabling them to reach a long distance or run quickly through the air space (vacuum and, if applicable). A bridge is different from an access point in many ways. We have a few things from our bridge project and learned the most important is the legitimacyEdition.
The sky is full of beginnings for the day, we know it or not. Scientists have a numerical scale, called the electromagnetic spectrum, the nature of the signals and classify this scale of human language, visible light, microwaves, X-rays and all levels of radiation. The scale is often in the electromagnetic frequency kHz, MHz and GHz Express (kilo, mega or giga hertz) and a logarithmic curve. Human language exists, in kHz. Radio workMHz to GHz levels. Light and radiation demonstrated in the higher regions GHz energy content varies depending on the scale, such as a frequency.
The use of the airspace is controlled. For example, the police will knock on our door when after 11 clock crying out loud. We're not focusing on a strong spotlight in a nearby house at any time. The radio is a different story because they see a receiver or detect signals required. Due to this invisible nature, is the use of radio spectrumexpressly regulated by governments. As regards New Zealand is concerned, there is a Radio Spectrum Policy Group Management (RSM) at the Ministry of Economic Development dedicated to the use of regulated access. Requires licensing of the spectrum, with few exceptions, these bands are free to operate normally very small. Our daily use of wireless devices, the transmission can have a free license or 5 GHz airspace for 2.4-GHz. RSM has the maximum amount of energy transferredsent by each side of wireless equipment so that the restricted airspace that can accommodate multiple users. The legal limit was virtually imposed a maximum limit on the distance and speed of transmission, since both measures depends on the energy of the signal.
We only found that many wireless products on the parameters of the two market conditions. One is the possibility of use as 2.4GHz or 5GHz. The other is the transmission protocol adopted byIEEE (Institute of Electrical and Electronic Engineering) in the U.S. as 802.11a, b, g and n. Some of these products are intended for the production of radio signals well above the legal limit allowed in every country. international producers, and, possibly, the local distributors are not responsible for any injury, but users are.
Most WLAN access points are installed in the school grounds on campus for use by teachers and pupils. Even if the signals arelimits of the law can not be angry neighbors houses, "because the signals were weakened by the distance between the center and the edge of campus. A bridge is a different story. A bridge across areas of different properties and the strength of the signals is easily detected. RSM legal limits in units of equivalent isotropic radiated power EIRP is given. This leads to more information about antenna technology.
Amplified antenna and radio signalsThe amplification is expressed in dBi for the isotropic Decibel. In simple terms, is the relationship between the vector sum of signal strength in all directions, a simple reference design. A bridge is a point to point layout and you would think that there is only a stream of radio signals. This is not true and depends on the shape of the antenna. Satellite dishes would be close to a single stream of data and showed that they can not be commercially exploited. Flat panels are a goodCompromise with respect to the physical dimension can be smaller and the signals are highly concentrated. Obviously, an antenna shaped like a stick is to install the cheaper version, but a rod radiates in all directions. We generally parabolic or flat screens and bridge in the form of bars for access points.
If you have visited Taipei, the Grand Hotel, you know him as a symbol, because the Grand Hotel looks like an ancient Chinese imperial residence. The Grand Hotel is situated on a hill and enjoys a panoramicOverlooking a large part of Taipei City, including the river Dashui. Our consultant is wireless Bank commissioned a test of the Wireless Bridge on the Grand Hotel along the river and a park. The line is 1.7 km away and the natural bridge reaches a throughput of 81Mbps (megabits per second). The bridge is possible on a standard LAN cable, but a standard cable connection 100Mbps only be compared to 60Mbps for about 100metres.
While the costsa pair of wireless bridges is much lower than the laying of a cable more than 1.7 mile to not take into account the legal and technical issues, maintenance considerations will make the biggest difference. Besides the cost advantage of a wireless approach also achieved a higher power. This seems ideal. Beware of catches. This item has been increased to the point of law only for the attention and there are technical problems to a smooth and successfulInstallation.
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