Exploring the secrets of the wireless route transmission rate

When we purchase a wireless router, we believe that the vast majority of users only care about the wireless transmission rate, which often appears in the prominent position of the product packaging, it has already become a gold icon used by major wireless router manufacturers for publicity, but you can understand that this number is only a theoretical value, but it is quite different from the actual transmission rate of wireless routes, so what is the water content of this gold signboard? So please follow me to practice and understand it in person.

I learned computer science before I started literacy. If not, it doesn't matter. I am not here to help you literacy ~! The wireless transmission rate identified by a common wireless router is measured in Mbps, so many users mistakenly think that MB and Mb are a meaning. In fact, there is a big difference between the two, there is no difference between layers. This is the so-called layman watching and watching, and the experts guard the door.) However, the daily use of MB is very powerful. The full name of MB is MByte ): A storage unit in a computer reads "MB ". The data unit MB and Mb pay attention to the Case sensitivity of the B Letter) is often mistaken for a meaning, in fact, the meaning of MByte is "MB", the meaning of Mbit is "Mb ". MByte refers to the number of bytes and Mbit refers to the number of bits. Both are data measurement units, but they are completely different. Byte is the number of bytes, and bit is the number of digits. Every eight bits in the computer is a Byte, that is, 1 Byte = 8 bits, which is the ing. Therefore, in the computer class, the teacher taught us to pay attention to the Case sensitivity of the B Letter When writing the unit. The meaning is different. During the examination, you should not pay attention to the duck eggs) so what we see300 Mbps, 150 Mbps, 54Mbps, and 11 MbpsIf these theoretical wireless transmission rates are converted into Mb/s units that we can easily understand, their theoretical wireless transmission rates should be37.5 MB/s, 18.75 MB/s, 6.75 MB/s, and 1.375 MB/s. In addition, the well-known 100 Mbps network cable is also measured in Mbps. The theoretical wired transmission rate should be12.5 MB/s (100,000 KB/8 = 12,500 = 12.5 MB).
For another example, the network speed 1 M usually refers to 1 Mbps (check whether the network connection speed in the lower right corner of your computer is lower case B) the actual download speed is up to 125KB/S1000/8 = 125KB/S.

I believe that you have understood the differences between MB and Mb, and have a new understanding of the theoretical transmission rate of wireless routing, at this time, you will find that the gold signboard used by the major wireless router manufacturers for publicity is very miserable, and the data transmission rate they boast is mbps for the M-byte theory, the maximum wireless transmission rate should be37.5 MB/s,Note: This is only the best state in theory.Ideal is full and realisticNext, let's test it. I only have a 54Mbps Wireless AP. I can only use this to test it.

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I also went to literacy and introduced wireless network protocols. With the development of wireless networks, 802.11b, 802.11a, 802.11g, and 802.11n have been developed based on 802.11, the specific frequency and speed of these protocol members are as follows:
Protocol frequency rate
802.11 2.4 GHz 2 Mbps
802.11a 5 GHz 54 Mbps
802.11b 2.4 GHz 11 Mbps
802.11g 2.4 GHz 54 Mbps
802.11n 2.4 or 5 GHz Mbps or higher
802.11 protocol with the development and popularization of extended protocols, it has been gradually eliminated. 802.11b is a wireless network protocol formed after the 802.11 protocol. It was launched for a while, but it only has 11 mbps bandwidth and cannot meet the special business requirements of many local area networks. Later, the emergence of 802.11a, the protocol supports a rate of up to 54 Mbps, can meet the needs of most businesses, but it operates at 5 GHz, and is not compatible with 802.11 and 802.11b in hardware, it is difficult to seize the existing customer base of 802.11b, which is not popularized. In order to maintain the high speed and compatibility of 802.11b, We have optimized the 802.11g protocol on the basis of 802.11b. It is compatible with the GHz working frequency band of 802.11b, it has good hardware compatibility with the 802.11b customer group and has become the mainstream. After the 802.11g protocol, people improved the wireless network rate and better band compatibility protocol-802.11n, because it was a recent wireless network protocol, at present, most people will confuse Wi-Fi with IEEE 802.11, and even equate Wi-Fi with wireless networks. The so-called Wi-Fi is actually an alias of the IEEE 802.11b standard.

The following figure shows that my wireless network card supports the/G/N Frequency Band. Since My Wireless AP can only support up to G, do I see network G-only? This directly tells us that the maximum transmission rate of this AP is only 54 Mbps. If our Wireless AP can support the 802.11n protocol, of course we have to choose n, because its transmission speed can reach Mbps or higher, it is six times faster than the 802.11g protocol. Unfortunately, my AP can only support up to 802.11g protocol, so here I change the wireless Nic mode to 802.11 GB,

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WirelessMon is a tool that allows users to monitor wireless adapters and aggregation statuses and display real-time information about nearby wireless access points or base stations, lists the signal strength between the computer and the base station, and monitors the transmission speed of the wireless network in real time, so that we can understand the download speed or stability of the network. Http://www.passmark.com/ftp/wirelessmon.exe

Connect to the wireless network and run the software to see the relevant information.

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Because wireless signals are transmitted in a straight line, if obstacles are encountered during transmission, the signal strength of wireless communication will be weakened, especially after passing through metal obstacles, the attenuation of wireless signals is very large. Some experiments have proved that, within a 10-meter distance, after the wireless signal passes through two brick walls, it can still reach the nominal highest transmission rate, but after passing through a layer of floor, the transfer rate is only half of the nominal rate. It can be seen that the reinforced concrete wall will greatly weaken the wireless signal and reasonably place the wireless router (or Wireless AP) will become one of the important factors affecting the strength of the wireless signal. Therefore, when setting up a wireless network, place the wireless router at the interchange of several rooms, with the best effect. For information about wireless signal strength, please refer to the http://dalipc.blog.51cto.com/1856667/351639, I here to test the transmission speed of the method is not very scientific and convincing method, I am lazy ha, for more scientific testing methods, please refer to the article I reproduced http://user.qzone.qq.com/185741745/infocenter! App = 2 & amp; pos = 1341195432

Next I will put my laptop and Wireless AP together, which is equivalent to the best signal. Below, we can see that the highest signal intensity can only reach 92%, start to copy a mb qq installer from another computer, check its time and transmission speed, and calculate its average value, starting from the timing, we find that the copy speed starts to grow from small to small. We take a relatively stable value in the middle. here we can see that the transmission speed is 2.22 MB/s per second, then we can see that the time taken after the completion is exactly 22/s, so we can conclude that: (2, 220KB * 22 S = 48,840 KB = 48.84 MB) the file of the 48.84MB size can be transmitted, the size of our file is only MB, so it can be completely transmitted.

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The signal strength is reduced from-16dBm to-51dBm 5 meters away from the Wireless AP, but we find that the transmission speed and time are essentially different, therefore, it is concluded that as long as your signal strength is between 0 and-50dbm, You can transmit data without any problems.

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This figure shows that the signal strength transmission speed from 0 to-50dbm has not changed much.

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The signal strength dropped to-60dBm when a data center came about 8 meters away. At this time, the transmission speed slowed down significantly, and only about MB was transmitted per second.

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The signal strength dropped to-68dBm when a room came about 10 meters away, and the transmission speed slowed down, only about KB per second.

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Continue to the position about 14 meters away from the Wireless AP, and the signal drops to-73dBm. At this time, I want to copy another file of 46.7MB size, which is basically no solution.

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Summary:From the above test results, we can see that the ideal transmission speed of the wireless routing theory of 54Mbps should be 6.75 MB/s, but the actual application is only 2.22 MB/s, the transmission speed is three times different from the ideal status. These manufacturers are not common pitfalls. Therefore, when a layman buys a wireless route, the transmission speed is 54 Mbps. He thinks the transmission speed should reach 54 MB/s, if he doesn't reach the upper limit, he will feel very embarrassed. The expert knows that the ideal transmission speed is 6.75 MB/s, but the actual speed is only 2 MB/s, after reading this article, are you still confused about the wireless transmission rate? It's time to wake up.

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