The error is generated because the decay changes the voltage of the signal during signal transmission, causing the signal to be corrupted during transmission, resulting in bit errors. Pulses caused by noise, AC or lightning, transmission equipment failures, and other factors can cause bit error rates (such as a transmitted signal of 1 and a received 0; and vice versa). A variety of different specifications of equipment, have a strict definition of bit error rate, such as the usual video / audio bi-directional optical transceiver error rate should be: (BER) ≤ 10E-9.
For various reasons, digital signals inevitably generate errors during transmission. For example, the external signal is disturbed during transmission, or the transmitted signal is distorted due to the insufficient quality of each component in the communication system. When the interference or signal distortion is affected to a certain extent, an error occurs.
What is wrong? In data communication, if the transmitted signal is "1" and the received signal is "0", this is "error", that is, an error has occurred. The ratio of the number of bits of an error occurring in a digital signal received within a certain period of time to the total number of bits of a digital signal received at the same time is called a "bit error rate" and may also be called a "bit error rate". The BER (bit error ratio) is an indicator for measuring the accuracy of data transmission within a specified time.
The BER (bit error ratio) is an indicator for measuring the accuracy of data transmission within a specified time. Bit error rate = error in transmission / total number of codes transmitted *100%. If there is a bit error, there is a bit error rate.
In addition, the bit error rate is also defined as the frequency used to measure the occurrence of errors. The IEEE802.3 standard provides an acceptable maximum bit error rate of 10-10 for a 1000Base-T network. This bit error rate standard is set for pulse amplitude modulation (PAM-5) encoding, which is the encoding method of Gigabit Ethernet.
The bit error rate is the probability that a binary symbol is misrouted in the data transmission system.
Let the total number of binary data transmitted be N bits, and the number of bits in the error is Ne, then it is numerically approximately equal to:
There are several reasons why the bit error rate is below the standard (below 1.0e-8):
1, active devices in the network
The input or output of all active channels such as optical transmitters, optical receivers, amplifiers, set-top boxes, etc., or the signal level of a certain frequency point is too high, causing the device to be self-excited, or the level of the entire channel is too low.
2. The network does not match , and the reflection is serious, which causes the interference between the digital signal codes or the bit error rate.
The causes of network mismatch are as follows: cable water ingress, aging, oxidation, poor contact, formation of standing waves, large level unevenness in the frequency band, and poor frequency characteristics. As long as the investigation is carefully carried out, various network failures are eliminated, and the network technical indicators are returned to normal, and the signal transmission can be normal.
3, RF amplifier failure
Amplifier aging, characteristic deterioration, offset, self-excitation, severe distortion of the output signal of certain frequency bands, making digital electricity
It is difficult to decode the signal, and the Masek phenomenon occurs. After the maintenance personnel determine through the test that the amplifier is faulty, the fault will be eliminated as long as the amplifier is replaced and the technical specifications of the amplifier are adjusted.
Paperlike Screen Protector For IPad
Paperlike Screen Protector,iPad Paperlike Screen Protector,Paperlike Screen Protector iPad,Paper Like Screen Protector
Shenzhen Jianjiantong Technology Co., Ltd. , https://www.jjtscreenprotector.com