iPhone shutdown door extension: why mobile phone frequency strikes
[IT168 evaluation] Recently, discussions about the iPhone 6s automatic shutdown event continue, although Apple has taken some measures to deal with, on the one hand to inform users to use the iPhone at a suitable temperature, on the other hand to provide batteries for a specified batch of iPhone Replace service. However, things are often more complicated than imagined. Users complain about the iPhone, especially in the winter, the outdoor temperature is getting lower and lower, and the phenomenon of automatic shutdown of mobile phones has become more frequent. Even the Android phones in the author's hands have experienced similar phenomena. It can be seen that the low temperature has indeed become one of the reasons for the automatic shutdown of mobile phones. Questions have also arisen. Why do smart phones made up of sophisticated electronic components strike at low temperatures? The battery is the fault In fact, smart devices are difficult to work normally at low temperatures. Merchants often specify the normal operating temperature of the device in the package, and make certain explanations for the phenomenon of low temperature shutdown. Taking the iPhone as an example, it is recommended that users run the device between 0°C and 35°C. Under circumstances below 0°C, it may temporarily shorten the battery usage time and shut down automatically. It can be seen that the battery problem is the culprit behind the phenomenon. In terms of deployment, the batteries in smart devices are mostly lithium-ion batteries. The principle of charge and discharge of such batteries is still a chemical reaction. It can be seen through a simple illustration that in the discharged state, the lithium ions of the negative electrode pass through the electrolyte and reach the positive electrode through the separator, and this movement of lithium ions realizes the transfer of charge, thereby realizing the conversion of chemical energy into electrical energy. At low temperatures, the activity of the electrochemical reaction described above deteriorates, mainly in two aspects. The first is the diffusion rate of ions. The lower the temperature, the slower the diffusion of ions. That is to say, the transfer rate of ions between the two electrodes is slower, resulting in a low conversion efficiency of the electric energy, which shows that the power provided by the battery is greatly reduced. Secondly, the properties of the electrolyte and the separator in the battery are changed, and the passivation of the charged particles at the low temperature is reduced. In particular, the permeability of the battery separator deteriorates, so that the shuttle resistance of lithium ions in the battery becomes larger, reflecting that the internal resistance of the battery is increased, and the increased internal resistance functions as a certain voltage dividing function, so that the battery is provided to the external circuit. The voltage is reduced. Therefore, the low temperature tends to make the battery power and voltage appear unstable. When the power management chip of the mobile phone detects that the output of the battery is lower than the normal operation, it will be automatically shut down for the purpose of protecting the device. In other words, low-temperature shutdown is actually a kind of equipment protection measures designed by manufacturers. Of course, the trigger conditions of various manufacturers for this measure are not the same, which also leads to different performances of different mobile phones in low-temperature environment, and may be relatively "iPhone." Sensitive". "Shut down door" has a mystery Looking back at Apple's problems, this time the "shut-off door" broke out. From the point of view, it is undeniable that there are weather reasons, but according to feedback from different users, in the south with higher temperatures, there are actually 30% of the iPhone's remaining power. When the automatic shutdown, more 50% -60% of the power will automatically shut down the situation, we can see iPhone "shut the door" or have some of their own hardware problems. From the perspective of the final Apple solution, the so-called hardware problem should still be in the battery body, given that Apple did not give a certain explanation, it is likely that the quality of the corresponding batch of iPhone battery is probably off, after all, in the lithium battery With high material activity, it is difficult to control the consistency of quality. It is very likely that after one year's charge and discharge, the life span will drop sharply and the daily use requirements will not be met. In addition, the temperature in the north will suddenly drop and the low temperature will further destroy the battery. This makes the iPhone power management chip sensitive to capture this change, the automatic shutdown event will also blowout-type outbreak, has become a "shut-down door." How to survive in low temperature? It should be said that following Samsung's Note 7 “explosion doorâ€, iPhone’s “shut-down door†once again triggered people’s concern for mobile phone batteries. With the rapid development of semiconductor technology and communication technology, the functions and performance of mobile phones have been greatly improved. However, the slow development of battery technology has often become the key to hinder the further development of mobile phones. According to the current situation, there is still no major breakthrough in battery technology in the short term. What we can do is pay more attention to the use of mobile phones. It is recommended that you keep the amount of mobile phone power in the outdoors as much as possible during the winter to reduce the use of outdoor mobile phones. If possible, use earphones to make calls. Of course, the mobile phone is usually placed in the inner pocket of clothes, heated with body temperature, giving the mobile phone a warm winter and avoiding his strike. The definition of dual frequency band refers to the characteristic that the same communication device can work in two frequency bands. For example, a dual-band router means that it can work in 2.4GHz and 5.0GHz modes at the same time. Single frequency wireless router: It can only work in 2.4GHz mode. Its applied disciplines include communication technology (first-level discipline) and mobile communication (second-level discipline) 5.0G WIFI GPON ONU, 2.4G+5.0G WIFI GPON ONU, WIFI GPON ONU with 2.4G and 5.0G, GPON ONU with Dual Band, Dual Band WIFI GPON ONU Shenzhen GL-COM Technology CO.,LTD. , https://www.szglcom.com
ONU (Optical Network Unit) optical network unit, ONU is divided into active optical network unit and passive optical network unit. Generally, devices equipped with network monitoring including optical receivers, upstream optical transmitters, and multiple bridge amplifiers are called optical nodes. The PON uses a single optical fiber to connect to the OLT, and then the OLT connects to the ONU. ONU provides services such as data, IPTV (i.e. interactive network television), and voice (using IAD, i.e. Integrated Access Device), truly realizing "triple-play" applications. The ONU has two functions: it selectively receives the broadcast sent by the OLT, and responds to the OLT if the data needs to be received; collects and buffers the Ethernet data that the user needs to send, and sends it to the OLT according to the assigned sending window The end sends the buffered data. The application of ONU can effectively improve the uplink bandwidth utilization of the entire system, and it can also configure the channel bandwidth according to the network application environment and applicable service characteristics to carry as many end users as possible without affecting the communication efficiency and communication quality, and improve the network utilization Rate and reduce user costs.