Smart handThe "NFC" on the strap on the watch means that the nfc function is supported, and the nfc function is also called near field communication. NFC is an emerging technology that allows devices using NFC (such as mobile phones) to exchange data while in close proximity to each other.
Supports the nfc function. According to the query ZNDS information, the "NFC" on the strap on the smart watch means that the nfc function is supported, and the nfc function is also known as near field communication.
NFC is the Bluetooth antenna used to connect the phone to the watch and then the phone and the watch can be synchronized. The NFC function of the phone can read silverThe function of the line card may be few people know, simple operation method, open the NFC of the mobile phone, the same contact with the bank card, you can read the information of the bank card, wipe the transaction record, open the quick payment and the like, you can directly operate, convenient and quick consumption and query.
At present, there are usually two kinds of laptops with wireless network cards on the market: one is with wireless LAN card, in generalThe transmission protocol used is 8011B, the other is with wireless wide area network card, they generally use GPRS wireless transmission protocol.
Wireless business: also known as wireless public. GSM business phone follows the usage habits of ordinary phones, and has the communication function of mobile phones. Built-in billing system, saving the purchase of external meter investment; Lithium battery backup power supply solves the communication problem caused by voltage instability or power failure. The product is powerful and easy to operate. It can be used after inserting a SIM card.
A wireless phone is a communication device that looks similar to a landline phone, but has its rootsQuality is a wireless terminal. Different from the traditional fixed-line telephone, the communication process of wireless business phone is connected to the base station (BTS) through the air interface, and then transmitted from the base station to the base station controller (BSC), and finally to the mobile communication switching center (MSC) for phone connection. It does not rely on traditional subscriber lines to connect to the Public switched Telephone network (PSTN).
Advantages No monthly rent. (China Unicom, Telecom, mobile merchants rent 35 yuan/month. Individual customers rent 25 yuan/month). Advantages: Local call: 0.11 yuan/minute; Long call: 0.16 yuan/min. Advantage gives away a handTransmission test. Radio energy transmission for wireless power transmission, non-contact power transmission, through the transmitter to convert electrical energy into other forms of relay energy (such as electromagnetic field energy, laser, microwave and mechanical waves, etc.), after a distance transmission, and then through the receiver to convert relay energy into electrical energy, radio energy transmission.
2, the first is actually electromagnetic induction, that is, the transmission of energy between two coils. High school physics should have learned, the transformer is this principle, but the transformer coil has an iron core. The Tesla coil can achieve ultra-high pressure because the coil is loosely wound, allowing the magnetic field generated by the coil to escapeOut of the coil, direct action, do not worry about high pressure damage to the core. Tesla coils were therefore used to transmit commercial radio waves, but were later abandoned. 3, the principle of Tesla's wireless power transmission technology is to treat the earth as a conductor, so that low-frequency electromagnetic radiation forms resonance in it, and use the low atmosphere to transmit part of the energy, and combine with the upper atmosphere to form a loop.
4, Tesla coil is a high-voltage generator that uses circuit resonance for energy conversion. Its working principle is quite different from that of ordinary transformers. The coupling coefficient K of an ordinary transformer is generally close to 1, so the primary andThe secondary voltage is basically proportional; The coupling coefficient of the Tesla coil is generally less than 0.3, and when working, the two-stage voltage ratio changes with time, and the relationship is not linear.
5, the reason should not be a matter of scientific principles, but from the technical and cost aspects. Tesla's wireless power transmission technology has problems with electromagnetic radiation and efficiency, electromagnetic waves will spread out and its efficiency will rapidly decline because it follows the inverse square law of distance. If you want to build a megawatt wireless power transmitter, you have to pump a million watts of power into it all the time, even if the power side only wants itIt receives 10 watts of power.
6, simple solution: when Tesla engaged in wireless transmission and today's is completely different, now is a radio. And an antenna... and he's working on Earth's free solar power systems, systems that wirelessly transmit power from the ionosphere to the ground. The ionosphere is the upper atmosphere, a charged layer of positive and negative ions ionized by the solar wind. He wants to draw electricity straight from here, no electricity at all.
WLAN indicates Wireless Local Area Networks (WLAN) WLAN is a local area network (LAN) that works wirelessly in the 5GHz or 5GHz frequency band. WLAN communication systems, as an alternative to wired LAN, are generally used within the same building.
Full name of Wireless Local Area Networks Concept of wireless counterfeiting : Wireless Local area Networks; For short: WLAN. It is a very convenient data transmission system, which uses Radio Frequency (Radio Frequency; RF's technology uses electromagnetic waves to replace the old, impeding local area network of twin-pair copper wires to communicate in the air.
Wireless local area network is a particularly convenient data transmission system, it can use the radio frequency technology, the use of electromagnetic waves in the air for communication signal connection, so that users can use the wireless local area network access architecture, to achieve the ideal state of "information portability, convenience to the world".
Wireless LAN is the use of wireless technology to transmit data, voice and video signals over the air. As an alternative or extension of the traditional cabling network, the wireless local area network liberates individuals from the desk, so that they can access information anytime and anywhere, improving the office efficiency of employees.
Wireless LAN is short for Wireless Local Area Network, which refers to the application of wireless communication technology to communicate computer devicesTogether, it forms a network system that can communicate with each other and realize resource sharing. The nature of the wireless LAN is no longer the use of communication cables to connect the computer to the network, but through wireless connection, so that the construction of the network and the mobile terminal more flexible.
1, the second generation (2G) mobile communication network has been digital honeycomb due to the inherent shortcomings of 1G system such as low spectrum utilization, poor voice quality, small access capacity, poor confidentiality and can not provide data communication servicesInvented it? Let's take a look back at the development of WIFI, WIFI was originally created by a team led by Dr. John Sullivan, Dr. John Sullivan is an Australian, this team belongs to one of Australia's largest scientific research institutions, called the Commonwealth Scientific and Industrial Research Organization.
4, Wireless network is through the router or wireless AP radio frequency chip, emit 4G, 5GHz and other bands of signals, users use mobile phones, laptops and other devices, search and connect to the router's wireless network for Internet access.
5, the so-called wireless networkIs the use of radio waves as a medium for information transmission composed of wireless local area network (WLAN), and the use of wired networks is very similar, the biggest difference is the difference in the transmission medium, the use of radio technology to replace the network cable, and the wired network can be mutual backup.
6, if you have a wireless cat at home, after cracking the wireless routing function, you want to establish a wireless network. If your home has wired broadband, buy a wireless router so you can set up a wireless network. If you have Internet access in your office, buy a wireless router so you can set up a wireless network. If you have a telecom, mobile, Unicom wireless Internet access account and passwordYou can also access the Internet wirelessly via the public wireless networks of these wireless broadband operators.