H-antenna Placement
Time Limit:1000MS
Memory Limit:65536KB
64bit IO Format:%lld %llu Submit Status Practice POJ 3020
Description The Global aerial Centre has been allotted the task of building the fifth generation of mobile phone Nets in Sweden. The most striking reason so they got the job, is their discovery of a new, highly noise resistant, antenna. It's called 4DAir, and comes in four types. Each type ca
) The numerical value becomes smaller, the reading and writing is convenient. The total magnification of the electronic system is usually thousands of, tens of thousands of or even hundreds of thousands of, a radio from the antenna received from the signal to the speaker sound output, a whole to zoom in about 20,000 times times. In decibels, the logarithm is taken first, and the value is much smaller.(2) convenient operation. When the amplifier is cas
, which allows you to buy a wireless network card separately ".
The built-in MiniPCI wireless Nic does not integrate a signal antenna. Therefore, to install the MiniPCI Nic, in addition to requiring the laptop to reserve a MiniPCI slot, you must also have a preset antenna or a preset antenna. Not all brands of MiniPCI interface wireless NICs can be used in any mo
process.
Wireless NICs generally have two types of antennas: External antennas and built-in antennas. If the purchased wireless NICs do not have built-in antennas, you must purchase another one. However, the advantage of an external antenna is higher gain and better sensitivity. It can adjust the direction of the antenna to receive better signals. The built-in antenna
1. DBM
DBM is the absolute value of power. The formula is: 10lgp (power value/1 MW ).
[Example 1] If the transmit power P is 1 MW, it is converted to dBm and then 0dbm.
[Example 2] for 40 W power, the converted value in dBm unit should be:
10lg (40 W/1 MW) = 10lg (40000) = 10lg4 + 10lg10 + 10lg1000 = 46dbm.
2. DBI and DBD
DBI and DBD are the obtained Gain values (power gain). Both are relative values, but the reference standards are different. The reference of DBI is a full-direction
Several employees in unit A usually use laptops. Due to work reasons, they need to set up wireless networks for resource sharing. Also, several employees in Room B need wireless networking; by nature, building A slightly larger Wireless LAN can meet the wireless Internet access needs of all employees in Room A and room B. Considering the security concerns, the company intends to build A wireless LAN for several employees in Room A to prohibit employees in other offices from accessing the privacy
receiving devices located behind the obstacle will receive very weak signals or fail to receive signals. What about penetration?
This is what many netizens are most concerned about. We all hope that wireless signals can penetrate the walls of the house at least. To improve the ability of wireless signal to penetrate the wall, an effective way is to improve the antenna gain. We 'd better choose a product with a high
environment, the distance is short. Generally, the home wireless LAN equipment claim that the transmission distance is more than 100 meters, so the signal transmission distance is not a problem. However, the home environment brings about a new problem, that is, the home space is crowded and the space is not open enough. The walls in the room are the main obstacles. The wireless LAN uses wireless microwave frequencies. The biggest characteristic of microwave is that it is almost linearly transmi
transmit signals from the antenna to various directions. Therefore, it is necessary to consider the signal strength based on the transmission radius. If our router is close to the wall of the neighbor apartment, they will get part of our signal. As a result, we can try to place the router in the center of the home without considering the limitations of the desktop computer and the home modem. In this way, the signal strength sent by the router can sp
Wireless Transmission path analysis is an important step in wireless transmission network design, through the analysis of the transmission path to facilitate the network designers to choose the appropriate type of antenna (direction, polarization, gain and other indicators) according to the margin size of the wireless link, install the antenna height, select the appropriate feed cable and length. The follow
in the middle of the sea? That's the bridge! Amazing! The total length of the Highway Bridge in Shenzhen Bay is 5545, and the length of the side bridge in Shenzhen is about 2040. The bridge is constructed according to the standard of the two-way six-lane expressway. The bridge deck is 38.6 in width and has a design life of 120, it is a cable-stayed bridge with single-tower single-cable surface Steel Box Girder. It is currently the widest and highest standard highway bridge in China. the bridge
different wireless access devices. Make sure each one of them is able to surf the internet efficiently and wirelessly. To adjust the antenna position to promote network performance Normally, wireless internet nodes or wireless router devices will be attached to the Internet antenna, and different models of equipment with the antenna is different, then the in
distribution of the AP. In certain cases, each of these three methods works well, but none of the three methods can fundamentally address the problem of radio interference. Today, the majority of the AP is the omni-polar antenna used in the market. These antennas transmit and receive at a comparable rate in all directions. Since these antennas transmit and receive at the same speed in any case, the only option for these devices is to confront the dis
IEEE802.11 and ieee802.11b standards, can easily increase the wireless LAN load capacity and reduce the total cost.The wireless network of 80,000 People stadium project is divided into two parts: wireless network backbone bridge part and wireless network indoor and outdoor coverage part. The backbone bridge part uses the wireless network Bridge and the directional antenna completes the wired network the extension, the covering part includes Shanghai
The RF signal of the radio transmitters output is transmitted to the antenna via a feeder (cable) and radiated out by the antenna in the form of electromagnetic waves. ElectromagneticWhen the wave arrives at the receiving location, it is received by the antenna (only a small fraction of the power is received) and sent to the radio receiver via the feeder.Therefor
of wireless networks is much more difficult than ensuring the security of wired networks. Because the wired network only has a limited number of fixed access points, and the wireless network can be connected from any point in the range permitted by the antenna.
Design antenna placement
The first step to keep the Wireless Access Point Closed is to place the antenna
interference from nearby electronic devices during use, therefore, when setting the placement of wireless routers, we must remember to stay away from microwave ovens, refrigerators, and other household appliances.
A good antenna is also an effective way to ensure the wireless transmission distance and Stability of routers. Some high-end wireless routers use dual antennas, generally, multi-antenna products
points or wireless routers as wireless base stations, basically not involving bridges. How wide is the coverage of common Wireless AP? According to the protocol standard, the coverage of IEEE 802.11b and IEEE 802.11g is: 100 indoors and 300 outdoors. This value is only a theoretical value. In practical application, in addition to signal connection, it also has the value of speed. Therefore, the actual use range of Wi-Fi wireless products is: 30 meters indoors and 100 meters outdoors (no obstacl
sometimes called space diversity because it uses multi-space channels to transmit and receive data. MIMO can be deployed only when the site mobile devices) or access point AP (AP) Support MIMO.
MIMO can increase the wireless range and improve the performance. The 802.11n site connected to the old 802.11g access point can connect to farther distances at a higher speed. For example, if you use an old site, the connection speed from 25 feet to the access point is 1 Mbps, and the site speed is 2 Mb
, this naturally slows down the WLAN transmission speed. In addition, the wireless network transmission distance is limited, although the average wireless router nominal transmission distance can reach 100 ~ 300 meters, but in actual use, if there is a barrier, this distance will be sharply shortened and will cause data transmission to slow down.
Knowing the cause of slow transmission speed, we can solve this problem in a targeted manner. First of all, we need to grasp the layout. It is best to
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