isotropic antenna

Protecting our wireless networks to the maximum extent is a matter of great concern to us. From which aspects should we manage and set them? Here we will introduce it to you. The purpose of reasonably protecting wireless access points is to isolate wireless networks from outsiders who are not authorized to use services. It is often easy to do. In terms of security, wireless networks are usually more difficult to protect than fixed wired networks, because the number of fixed physical access point

psmp-dtt1 moment), and then sequentially send the node corresponding to the buffer broadcast frame, here PSMP-DTT time, the inter-frame interval can be used rifs, in order to achieve higher efficiency. For the ACK part, because the author did not do the detailed textual research, so did not describe. When the PSMP-DTT time is over, the node sends a data frame, such as STA1, to send the upstream data in the PSMP-UTT1, in turn, within its corresponding upstream dispatch cycle. When the Psmp-utt t

Because a desktop with a wireless network card is equipped with a black wireless network card antenna, you must connect to the wireless network card antenna before normal wireless Internet access.Solution:1. Check that the wireless Nic Antenna interface behind the host is not connected. The Wireless NIC antenna comes s

is surrounded by peripheral devices such as capacitors, resistors, etc. that are required for the chip to work properly. The yellow serpentine pattern on the left is the PCB antenna. It is a way of using the wires on the printed circuit board as an antenna. The advantage of this antenna is that it is smaller and cheaper than the external

send data to the reader. The data includes not only the ID (globally unique ID), but also the data pre-existing in the eeprom of the label. Because passive tags have the advantages of low price, small size, and no power supply. RFID tags in the market are mostly passive. Semi-active Generally, a passive tag antenna has two tasks: first, to receive the electromagnetic wave sent by the reader, to drive the tag IC; second, to return the signal from the

there are tags nearby. RFID is usually called a near-pairing system for communication at a very close distance. The range of near-pairing systems is usually 0 to 1 cm. This means that the tag is appended to the reader or pressed to the reader. The advantage of this close distance is that the label battery plant can produce a lot of energy. This energy is sufficient to support tag communication without the need for Built-in power. Near-matching is also conducive to highly confidential occasions.

, and the distance from the battery should be far enough. HW also requires that the Id be placed near the antenna without metal accessories. We can imagine that the manufacturing cost of a mobile phone with a built-in antenna is 20-25% more expensive than that of a mobile phone with an external antenna. The main factor is the design of the

Wireless networks have become the preferred network access solution for families and small and medium-sized enterprises, and some problems have emerged. Due to the large area of some houses, the structure of the residential buildings is changeable, and there are many obstacles, the signal attenuation of the wireless network is great, resulting in incomplete wireless coverage, weak wireless signal strength and low wireless speed in some areas, there are even wireless blind spots and other situati

online.SIM300 Module appearance The SIM300 is a three-band Gsm/gprs module that operates on a global scale of egsm 900MHz, DCS 1800MHz, PCS 1900MHz Three frequencies, provides up to 10 GPRS multi-channel types, and supports CS-1, CS-2, CS-3 and CS-4 four kinds of GPRS coding schemes. SIM300 internal function modules are:Keyboard and SPI type LCD interface for users to develop their own application equipment.Two serial ports with debug and data output to help developers develop products more ea

Establish communication links between two points (e.g. headquarters and branch offices, network centers and communities). According to customer needs and the actual survey of the situation, there are the following types of transmission:(1) AB two points between visual, no obstruction, no electromagnetic interference, or small interference, AB two points between the distance between the network bridge equipment communication distance requirements.Can use the point to point Way direct transmission

The extensive use of wireless networks also brings about the security of wireless networks. Because wireless networks are different from wired network physical node access controllability, the security of wireless networks deserves our attention. For the current wireless network, we can improve the security of the wireless network through the following settings. 1. Disable unauthorized access The key to ensuring the security of wireless access points is to prohibit unauthorized users from access

own hardware. The wireless transmission rate is mostly 54 M, and the maximum is no more than 150 M. it is meaningless to have a high Router speed. Look at the brand. Be sure to select a big-brand product, because the chip that really determines the performance of the wireless router is its. The chips used by major brands are of high quality and stable performance. Some brands use low-end chips to reduce costs. Although some parameters are high, the performance is unstable. Look at the

One of the most prominent advantages of the Siemens SX1 mobile phone is that it supports stereo MP3 and built-in FM. Although the original stereo PTT headset is of good quality, it can also be used as an antenna with built-in FM, however, one of the traditional methods of using a Siemens mobile phone is to use a headset adapter to enable the use of standard 5mm stereo headphones, such as senhaiser mx300/400/500. Therefore, the modification of the SX1

, it can be widely used for interconnection between different buildings. In addition, according to different protocols, wireless bridges can be divided into 802.11b or 802.11 in the GHz band and 802.11a wireless bridges in the GHz band. In the absence of high obstacle peaks or buildings), a pair of fast networking and temporary networking for field operations. The distance depends on the environment and the antenna, and now 7km point-to-point microwa

Wireless LAN has become one of the most commonly used network technologies. However, if we are faced with a weak network signal, how can we solve it. Here is a detailed introduction. Q: I am now using a wireless LAN, but I feel that the data transmission speed is very slow. Is there any solution? A: It is estimated that the signal status is poor. You can try to add an external antenna or adjust the wireless channel to improve the communication speed.

With the development of technology, the number of technical problems also increases. For wireless networks, improving or improving the security of networks also brings inevitable problems. Here we will introduce them in detail. The extensive use of wireless networks also brings about the security of wireless networks. Because wireless networks are different from wired network physical node access controllability, the security of wireless networks deserves our attention. For the current wireless

priority. This is why such technology has been vigorously promoted internationally in recent years. However, the New Fixed Wireless Access Network must be FWA with a wide bandwidth to meet the needs of the user's development of data communication trends. As a matter of fact, the wireless cellular network of mobile communication has evolved from the current second generation to the coming third generation, and even to the far-reaching fourth generation. It also attaches great importance to the c

For solutions with weak Wireless LAN signal, the problem of Wireless LAN signal is very hot. As the name suggests, there are many ways to solve the problem of Wireless LAN signal, that is, the virtual network channel of the wireless router. This article also introduces several popular wireless routers on the market. Q: I am now using a wireless LAN, but I feel that the data transmission speed is very slow. Is there any solution? A: It is estimated that the signal status is poor. You can try to a

will not be perfect. After all, those obstacles will directly affect the normal transmission of data signals in the wireless LAN. 2. When the distance between the remote network and the local LAN is relatively long, we can appropriately reduce the size of the network transmission bandwidth to achieve the purpose of long-distance data transmission. If we really need to implement long-distance wireless transmission, we may try to set up a wireless LAN relay station in the middle so as to bypass t

overlapping frequencies, and can even theoretically overlap to an infinite number. However, to increase the sensitivity of demodulation, LTE currently supports half of the overlapping wavelength of OFDM. MIMO In fact, one of the important reasons why LTE abandoned CDMA in the Early Days was that CDMA had poor support for MIMO, while the sub-carrier data used by OFDM was converting serial data into parallel data, parallel data can be well adapted to MIMO reception. (For the reason why CDMA is no