A point to point wireless bridge outdoor is a bridging of wireless networks, which can bridge communication between two or more networks (a point to point wireless bridge outdoor is also a branch of wireless AP). In addition to the basic characteristics of the above wired network bridge, the wireless network bridge works in the 2.4G or 5.8G frequency band that is exempt from applying for wireless licenses, so it is more convenient to deploy than other wired network equipment.
Its transmission standard often adopts 802.11b or 802.11g, 802.11a standard, and the data rate of 802.11b standard is 11Mbps. On the premise of maintaining sufficient data transmission bandwidth, 802.11b can usually provide the actual data rate of 4Mbps to 6Mbps, while 802.11 g. The point to point wireless bridge outdoor of the 802.11a standard have a transmission bandwidth of 54Mbps, and the actual data rate can reach about 5 times that of 802.11b.
In the manufacturer's publicity description, although many wireless APs or wireless routers also have bridge functions, and are also called wireless bridges by manufacturers, the wireless bridges we talk about in this article strictly refer to the transmission distance of 1-20 Products above kilometers, rather than bridging within a few hundred meters of ordinary wireless APs or wireless routers.
1. What is a point to point wireless bridge outdoor
Point to point wireless bridge outdoor are designed for point-to-point interconnection using wireless for long-distance data transmission.
To understand the point to point wireless bridge outdoor from the function, it can be used to connect two or more independent network segments, these independent network segments are usually located in different buildings, hundreds of meters to tens of kilometers apart. So it can be widely used in the interconnection between different buildings. At the same time, according to different protocols, wireless bridges can be divided into 802.11b or 802.11G in the 2.4GHz band and 802.11a wireless bridges in the 5.8GHz band. The wireless bridge has three working modes, point-to-point, point-to-multipoint, and relay connection. It is especially suitable for long-distance communication in cities. It has 2 access methods, IP interface access and IP+E1 dual interface access.
Under the condition of no tall obstacles (mountains or buildings), one-to-one speed networking and temporary networking for field operations. Its working distance depends on the environment and the antenna, and the point-to-point microwave interconnection is now 7km. A pair of 27dbi directional antennas can achieve 10km point-to-point microwave interconnection. The 12dbi directional antenna can realize point-to-point microwave interconnection of 2km; a pair of point to point wireless bridge outdoor that only realize the function of the link layer are transparent bridges, and the 24dbi directional antenna with network layer functions such as routing can realize heterogeneous The devices connected to the network are called wireless routers, which can also be used as layer 3 bridges.
Point to point wireless bridge outdoor are usually used outdoors and are mainly used to connect two networks. It is impossible to use only one wireless bridge, and more than two are required, while APs can be used alone. The wireless bridge has high power, long transmission distance (up to about 50km), strong anti-interference ability, etc. It does not have its own antenna, and is generally equipped with a parabolic antenna to achieve long-distance point-to-point connection.
Now there are 802.11n point to point wireless bridge outdoor on the market, and the transmission rate can reach more than 300Mbps. However, due to various factors, the actual rate is far lower than the value advertised by the merchant. But compared with the development of 11g rate, it is believed that more new products will be derived with the emergence of new technologies, which has indeed improved a lot, which also makes it possible for us to require high bandwidth and high transmission rate. With the continuous development of technology, it is believed that more new products will be derived with the emergence of new technologies.
2. Introduction to the settings of the point to point wireless bridge outdoor
Establish a communication connection between two points (such as headquarters and branches, network center and community, etc.). According to the customer's needs and the actual situation of the survey, the transmission method is determined, and the appropriate point to point wireless bridge outdoor settings are made. There are the following transmission methods:
2.1 The two points of AB are visible; there is no obstacle blocking; no electromagnetic interference, or the interference is small; the distance between the two points AB meets the requirements of the communication distance of the bridge equipment.
It can be directly transmitted by point-to-point mode: a point to point wireless bridge outdoor is placed in building A, and a directional antenna is placed on the top; building B is also placed without a bridge, and a directional antenna is placed on the top. After the wireless bridges in the two places are connected to the local antenna through the feeder, the wireless communication between the two points can be quickly established. The wireless bridges are respectively connected to the network switches in various places through the CAT5e twisted pair. In this way, the two networks can be connected as one.
2.2 The two points AB are invisible, but they can be seen indirectly through a building C. And two points AC and two points BC meet the requirements of bridge device communication. We use the relay method, with Building C as the relay point. AB each place a bridge and a directional antenna.
3. The method of point to point wireless bridge outdoor to avoid interference
A point to point wireless bridge outdoor is a bridging of wireless networks. It uses wireless transmission to build a bridge for communication between two or more networks. Wireless bridges are divided into circuit bridges and data bridges from the communication mechanism.
3.1 Interference from external buildings
When the wireless signal encounters the occlusion of the object during the transmission process, if the transmission distance of the signal is not far, the transmission direction will change to a certain extent by means of refraction under the occlusion environment, and the signal will be reflected and attenuated. . Although the signal can be received, the signal strength of the received signal is very weak, and the bandwidth will be greatly attenuated.
If a metal object is encountered during the propagation, it will also increase the attenuation of the signal. If there is occlusion transmission in the case of transmitting video signals, then the signal stability must be difficult to guarantee. The transmission of network signals does not require much bandwidth, so the transmission of network signals in a sheltered environment can basically meet the requirements.
Therefore, when choosing the installation location of the wireless monitoring equipment, try to make the middle unobstructed as much as possible, and the middle from the transmitting end to the receiving end is visible, so as to avoid the attenuation of the microwave signal, and the monitoring center can receive high-strength wireless signals, thereby improving the Monitor the effect. If there is an obstruction between the transmitting end and the receiving end, we can avoid the intermediate obstruction by relaying.
3.2 Interference from similar equipment
In the wireless monitoring system, the analog wireless monitoring system is a fool. We can only check the interference source slowly, while the digital wireless monitoring equipment belongs to the intelligent wireless monitoring system. We only need to scan it through the software. The same frequency nearby, so you can avoid this frequency when setting.
At present, wireless monitoring equipment can be seen everywhere, such as mobile, Unicom signal towers, walkie-talkies, wireless, etc., which are all transmitted by wireless signals, which will definitely interfere with wireless monitoring equipment. For digital wireless monitoring equipment, avoid the signal interference of surrounding similar equipment or equipment with the same function. The signal source of this interference signal may be the normal signal source in our system, and the receiving end may not receive the signal or receive the same signal due to the same frequency or proximity, making it difficult for the receiving terminal to identify.
In this case, we can adjust the frequency of the wireless device, choose a clean channel, or change the position of the transmitter or receiver of the wireless device to increase the distance between the devices.
3.3 How to judge whether the bridge receives interference
It can be judged by monitoring the screen. If there are packet loss, screen instability, clutter, black stripes, ripples, etc., if there is a device that is disturbed, you need to find the cause one by one.
Not all equipment interferes with wireless, such as mobile, Unicom signal towers, walkie-talkies, wireless phones, etc., have no effect on wireless microwave equipment. When there is an interference source, you can adjust the frequency of the equipment, or choose a location far away from the interference source to install, thus greatly reducing the interference to wireless microwave equipment.
4. 6 common faults of point to point wireless bridge outdoor
4.1 Unable to transmit or receive signals: Start with simple problems first, check the network cable first, then replace the crystal head, and finally check whether the network port of the device is damaged.
4.2 The monitor monitor is blurry and intermittent, and the signal strength of the point to point wireless bridge outdoor is very low: if this happens, first check whether the distance between the wireless bridges is within the applicable distance; secondly, check whether the antenna angle is correct, or try to use higher gain antenna.
4.3 If the point to point wireless bridge outdoor has only one P/S light that is always on, but cannot be pinged: first, restore the wireless bridge to factory settings, and then reconfigure it; then replace the PoE power module to see if it can be used normally. Connect the wireless bridge directly to the computer with a network cable to see if it can be connected; if it cannot be connected, the wireless bridge is broken.
4.4 Communication is interrupted after a thunderstorm: First, check whether the PoE power supply is burned out, then check whether the network port is normal, and finally check whether the main board of the device is burned out due to lightning strikes. Under normal circumstances, it is recommended to take lightning protection measures before installing a point to point wireless bridge outdoor in a thunderstorm area.
4.5 After the connection to the point to point wireless bridge outdoor is normal, the PoE indicator turns off, and turns on immediately after disconnecting the link: first check whether the wireless bridge is short-circuited, if it is short-circuited, the wireless bridge needs to be replaced.
4.6 Discontinuous transmission signal: First, we need to check whether the channels at both ends of the point to point wireless bridge outdoor are consistent, then check whether the country code is different, and finally check whether the version of the wireless bridge is the same. This is sorted according to the frequency of problems. The less likely it is in the back.
