What is a wireless AC controller? What does it do? Ac Controller,Gigabit Wlan Controller,Enterprise Ac Gateway,Wireless Ap Controller Shenzhen MovingComm Technology Co., Ltd. , https://www.movingcommiot.com
Wireless AC controller is a kind of network device, such as the AC100/150 of Fengrunda, which can be used to centrally control and manage wireless aps. It is the core of a wireless network and is responsible for managing all wireless aps in the wireless network. AP management includes: delivering configuration, modifying related configuration parameters, RF intelligent management, and access security control.
Why use a wireless controller, and what exactly does it do?
In fact, the role of the wireless controller is to play a gateway function between the WLAN and the Internet (on the router), and the data from different access points are aggregated and accessed to the Internet. The role of an access point (AP) is to complete wireless access, and it can control user access through network flags.
The role of wireless controllers
1, Flexible networking mode and excellent scalability
The AP does not need to be directly connected to the AC, so that the AP can be deployed in any place that needs to be covered through the network, such as you deploy an AP in each employee's home, and then connect to the wireless controller inside the enterprise through the VPN, you can expand the wireless network of the enterprise to the family of each enterprise member.
2, intelligent RF management functions, automatic deployment and fault recovery
Through the dedicated RF management module, we can initially estimate the AP deployment according to the user's architectural design drawing, and can calculate the average bandwidth of the wireless terminal, the coverage between AP and AP in the actual debugging process.
3. Centralized network management
All the configuration of the wireless network can be completed by configuring the wireless controller. For example, enable, manage, and maintain all AP devices and mobile terminals, including all functions such as radio wave spectrum, wireless security, access authentication, mobile roaming, and access users.
4, powerful roaming function support
The wireless controller uses AP as the boundary combined with fast RF management system, which greatly reduces the connection time between wireless client and AP, and thus realizes the function of fast roaming.
5. Load balancing
AP and wireless controller systems can distribute wireless users or terminals to nearby aps within the coverage area of an AP, ensuring the number of each wireless terminal or the sum of AP bandwidth transmission or the upper limit of each wireless terminal bandwidth.
6, wireless terminal positioning, rapid fault location and intrusion detection
Wireless controllers can track and locate the location of wireless terminals, such as wirelessly connected computers, PDAs and Wi-Fi mobile phones.
7, powerful access and security policy control
At present, the wireless system supports authentication of 802.1, WEB authentication, MAC, SSID, VPN, etc., and supports various encryption modes such as WEP, WPA, WPA-PSK, WPA2, etc., and all configurations can be configured globally through the wireless controller.
8, Qos support
AP and wireless switching systems can limit the maximum bandwidth of a user's wireless connection within each user's privileges. For different IP services, the system can also define different QoS queues through the wireless switch module. For example, for wireless voice applications, SIP and RTP protocols can be set in the high queue, while common applications such as http and ftp can be set in the low queue.
The wireless controller AC is more advanced than the AP, plays the role of manager in the wireless network, and the wireless controller AC also acts as a client to complete a series of functions in the wired network (such as authentication, authentication, etc.). However, wireless controller AC is not a WLAN device specified in the 802.11 protocol family, but as a supplement to the protocol in specific applications, and its price far exceeds that of ordinary access point (AP) devices.
In small-scale wireless networks that use only a few aps, it is not economical to use expensive wireless controller AC equipment. However, if the number of wireless aps is large, more than 20 can be used AC controller.
Xiaomi Piston In-Ear Headphones Standard Edition Evaluation Report
The domestic mobile phone industry is fiercely competitive, and the cost is layer by layer. As long as it hinders the price, it may be abandoned. In this case, many mobile phones no longer distribute matching headsets. Grab is good, there is no matching headset, consumers don't care at all. In actual use, for most people, the headset is really just needed, not dispensable. In this case, it has A special mobile phone plug-in [matching earphones] market, it is different from other headsets in the market segment, its users are very clear, that is, mobile phone users, the sound quality requirements are not so high, but the functionality More requirements, such as the need for a microphone, can call, etc. For the needs of these users, the traditional headset manufacturers have not actively followed up, when the potential market is getting bigger, it also means that real money will gradually In 2013, Xiaomi stepped in and released an in-ear earphone called "Piston".
After that, Xiaomi updated the piston earphones with a frequency of almost one year. He has released the piston, piston 2.0 and piston standard version [2015]. In order to further segment the market, there are various derivative versions, such as youth version and Lite version. In just 2 years, the sales of Xiaomi's piston headphones have grown dramatically. According to official data, the cumulative sales volume has exceeded 10 million. This sales result is far higher than the traditional headset brand. We can't take the "piston". One test "disregarded for the reason."
We bought three piston headphones, which are 29 yuan for the simple version, 99 yuan for the 2.0 and 2015 standard version. After the release of the gallery, we saw a lot of spit, which is normal, Soomal readers have higher requirements for sound quality, sorry The piston series is normal, but the purpose of buying these three headphones is not to buy it, but more to find out why it will succeed. Today's focus is on the 2015 Standard Edition, and the other two are mainly for comparison.
Millet has been the style is exaggerated propaganda, its headphone products are no exception, in "Xiaomi millet headphones [2015] Evaluation Report" [Author: Soomal] article, we severely criticized millet headphones The false propaganda. In the propaganda of the Piston series, there are also many problems. For example, the simplified version of the copy mentioned "high-strength pure copper voice coil, which not only enhances the transient response of the earphone, but also greatly prolongs the sounding unit. "Lifetime", these descriptions have no causal relationship, even wrong, here is a simple face, pure copper voice coil is too heavy, it will drag the vibration of the diaphragm, reduce transient performance, the common solution is to use copper clad aluminum The metal wire is wound around the tuned ring, which is the use of the legendary CCAW voice coil, and the copper wire voice coil has no necessary relationship with the service life. Although the official propaganda error is quite a lot, the impression of the rookie is so good. In the 2015 standard version of the copy, the parameters are also compared with the thousand yuan earphone products, to imply the price/performance ratio. There are many publicity slots, not one example here.
What we say is good, that is, Xiaomi pays attention to packaging and design. The 99 yuan earphone design is very valuable, and it is not cheap. The traditional manufacturer still uses disposable plastic packaging or carton packaging at this price. In terms of workmanship, there is no exquisite piston series. This is very important. Although 99 yuan is not a big number, a better appearance and a better sense of value will make people pay more quickly. Here we spit out the rambler H293P. Although the sound quality has received our recommendation rating, the appearance and workmanship...it seems to be worthless.
Xiaomi’s official copy mentioned the sandwich metal composite diaphragm. The structure is two layers of PTE sandwiched with a layer of metal. Xiaomi did not name the metal material, vaguely said to be “aerospace metalâ€, which is basically aluminum, The style of millet, if it is titanium, will definitely put the word "titanium" in the most conspicuous place. Generally speaking, the composite diaphragm is designed to fuse the physical properties of several materials, such as the rigidity of the diaphragm. And the smaller internal resistance, etc., what is the change in the sense of hearing? The official meaning is that "the treble is sweeter, the midrange is more accurate, the low frequency is more heavy, and in the end it is more balanced and more analytical." The technical content of the headphones is not high. One of the core technologies of the earphones is the diaphragm, and the diaphragm is expensive. Especially the diaphragm of small size is more demanding, and the composite diaphragm is obviously thicker. Let’s take a look. Piston 2.0, the piston 2.0 is called "the world's first bismuth alloy diaphragm in-ear earphone", not to mention compound, that is pure metal diaphragm, Xiaomi's propaganda at the time is "é“ alloy is the hardest of the existing earphone diaphragm The lightest and fastest material to deliver" is better than the diaphragm of the new piston. Why is it deprecated in the new version?
Xiaomi also specifically mentioned the "spiral trachea" in the posterior chamber. What is this? Here is a simple science. After installing the speaker, the diaphragm will split the acoustic cavity inside the ear shell to form two separate chambers. Knowing that the diaphragm is driven by the voice coil, but to control the diaphragm, you can not rely solely on the voice coil, but also the assistance of two chambers. The diaphragm movement will squeeze the air in the two chambers to form mutual The top support controls the pressure of the diaphragm to adjust the force of the diaphragm. This "spiral air tube" is used to adjust the pressure in the back chamber. According to this design, Xiaomi has many advantages, but it also caused us Curious, so we decided to violently disassemble it after the assessment, and see what happened.
In fact, we used the Xiaomi 4 and Xiaomi Note as the audio source device, and also used the 149 yuan Nubian headset and the 99 yuan Huawei engine headset and the current price of 99 yuan VSonic VSD1S headset as a reference. .
First of all, you can exclude the 29-element Lite version. Although it is called Lite version, it is not a simple package, the outer casing has changed, and the diaphragm is different. It is just another cheap design. Its sound performance is very poor. The high frequency is dark, and the intermediate frequency is simply submerged by the low frequency. The overall listening feeling is å—¡å—¡å—¡, although it is cheap, there is no price/performance ratio.
Compared to the piston 2.0, the 2015 standard version of the piston headphones, the sound quality does have an audible improvement. The high frequency of the piston 2.0 is brighter, but the details are not more, the high frequency is hard and thin, and the hard top is high. The distortion of the sense of hearing, and the 2015 version of the sound is much softer, although the resolution is not significantly improved, but the tolerance is greatly improved. The difference between the two intermediate frequencies is also large, the old version of the intermediate frequency has a sense of depression, in the playback of vocals When you are snoring, like a cold, especially the bass is more obvious. The 2015 version of the vocals is relatively prominent, and the resolution is relatively good. Both of the low frequencies are to cater to the rookie taste, the volume is loose, the details are obviously insufficient, the low frequency Transient and dynamic are not good, the strength is lacking, the low frequency is easy to paste, and the fast percussion is easy to mix together. In contrast, the 2015 version of the low frequency control is slightly better. In conjunction with the Xiaomi Note top version When the sound quality is better than the combination with Xiaomi 4, but the sound quality is not big, which also shows that the 2015 version with the Xiaomi Note top version, the full play version of the sound quality advantage.
When the first generation of the Pistons was released, it was compared with the most common tarballs of Apple equipment, Earpods. It claimed that it would not lose Earpods. By the 2015 version, Xiaomi had disdain to compare with Earpods. In actual comparison, it will find Earpods. The sound does not deliberately please the rookie, its sound should be balanced, soft and smooth. In the mid-low frequency transient dynamic performance, Earpods has obvious advantages, and more importantly, the overall sound density of Earpods is better, and the sound of piston headphones is better. All are imaginary.
Compared with Apple, what will happen to Nubia and Huawei? In this comparison, Xiaomi’s Piston 2.0 and 2015 editions are much better. Nubian and Huawei’s headphones are really bad, and they are completely unintentional.
We also specially arranged the comparison of VSD1S. This headset is currently priced at 99 yuan, which is comparable. In terms of sound quality, VSD1S has no overwhelming overwhelming advantage, and the sound is more refined, if the speed of progress from each generation of the piston comes Judging, the Pistons may need to go to the 2020 version to achieve the sound quality comparable to VSD1S. If you look at the packaging, I believe that most people will think that the Piston 2015 version is more value-for-money, the difference between the two is just as loud as the sound quality. Not only the contest of products, but also the competition between mobile phone manufacturers and headset manufacturers in terms of values.
The 99-yuan Piston 2015 version is worth or not worth it? We think it is worthwhile. Although its sound quality is still different from that of traditional manufacturers, it has a specific group of people. When it comes to mobile phones with ordinary sound quality, The 2015 version of the Pistons has been fairly good, because for better headphones, these phones may not be able to get a better sense of hearing. From this perspective, it is enough, and the appearance is good, the price is good, there will be no money to float. Feeling, so definitely more than negative, it is at least better than Nubian, Huawei. But from the trend, the overall sound quality of mobile phones is improving, Xiaomi is also playing HiFi, the new piston of the future Can you really meet these needs? Or is it still to eliminate a thousand yuan machine headset on the PPT? Piston 2.0 has been removed from the official website, and there is really no value. As for the piston version, don’t waste money, 29 yuan is good. It is also a meal.
From the 2015 version of the Pistons, we can see the reasons for the success of Xiaomi Pistons. We believe that it has accurately found the positioning, clear consumer groups and targeted design, relying on the growing ecology of Xiaomi to achieve success. Many people hate the propaganda of Xiaomi, a simple summary I have blown a good cow for Xiaomi, but I have neglected the fact that Xiaomi is also working hard. Simple understanding has created a rough imitation show. Huawei and Nubia have introduced headphones products to a great extent, only to see huge sales and success. It is the understanding of bragging, and the illusion that "I can also succeed", so Huawei's Nubian headset products are very bad, both products and markets are better than the Xiaomi Piston series.
Millet pistons with tens of millions of sales prove that the new market generated after the withdrawal of the plug-in, the traditional manufacturers must underestimate the potential of this market, as we said earlier, the difference in values, leading to the two vendors can not get a piece Although the products are all headphones, but in fact did not produce comprehensive competition, you do your mobile phone users, I do my voice quality small market. In fact, the two factions can be friendly collision, mutual integration, I believe better The product is completely predictable.