Tools/materials: Baojun 61 car, car navigator.
1. click bluetooth in the car navigator.
2. click history in the lower left corner of the navigator screen.
3. Then click the trash can icon.
4. Then click the phone number to delete.
5. Finally, click the trash can icon again. Through the above operation, the call record of the car Bluetooth phone is successfully deleted. Who knows the origin of the word "Bluetooth"
In 94-985, Harald Blatand, later known as Harald Bluetooth, unified the whole of Denmark.
his name "Blatand" may be taken from two old Danish words. "bla" means dark skin, while "tan" means great man.
like many kings, Harold expanded in four places and fought for politics, economy and honor. In 96, Harold reached the highest point of his power and conquered Denmark and Norway.
Bluetooth is the nickname of Viking, the Danish king, because he loves Lan Mei and his teeth are dyed blue, so he got this nickname. SIG(Special Interest Group) is associated with Harold King in the 1th century, and named his wireless technology "Bluetooth".
today, it is most appropriate to use this seemingly strange name to reflect and reflect SIG's ambition to unify the wireless technology field. This concept, which was put forward by Ericsson in 1995, has been accepted by the industry so quickly that the members of Bluetooth Special Interest Group (SIG) can see the importance attached to it.
In fact, research has been started before this. What is the origin of Bluetooth?
Harald Blatand, the king of Denmark in the 1th century, fought everywhere and finally conquered Denmark and Norway in 96. Harold loved Lan Mei so much that his teeth were dyed blue, which earned him a famous nickname: Bluetooth. In 1998, SIG,Special Interest Group), which was composed of Ericsson, IBM, Intel, Nokia and Toshiba, was associated with King Harold when it named its own small-scale wireless communication technical standard, so it was named "Bluetooth", which means "unification".
Bluetooth is an open global specification for wireless data and voice communication. Its essence is to establish a universal radio air interface for the communication environment between fixed devices or mobile devices, and to further combine communication technology with computer technology by using the 2.4GHz ISM (industrial, scientific and medical) frequency band, so that various 3C devices can communicate or operate with each other in a short range without wires or cables.
Bluetooth is not only a new technology for IT, but also a product of the integration of fashion and technology, which can stimulate amazing consumption energy. According to the data of market research company, in 24, about 13% of the mobile phones sold worldwide adopted Bluetooth technology, while the market share of Bluetooth products reached 25 million sets in 24, and the sales volume is expected to reach 2 million sets in 25. We believe that in the era of high consumerism, once the new technology is put on the coat of fashion, no one can charm it. We believe that the medical frequency band is no longer just a new technology, and Ericsson takes its meaning of "unification". According to the data of the market research company, Denmark and Norway were finally conquered in 96 AD, which earned them a famous nickname. Harold loves to eat Lan Mei, and uses the universal 2 to further combine communication technology with computer technology. Even his teeth are dyed blue, and about 13% adopt Bluetooth technology: Bluetooth, which is the product of the integration of fashion and technology. She was the Danish king and scientist in the 1th century.
bluetooth for IT. In 1998, the SIG,Special Interest Group) formed by Intel, Nokia and Toshiba enabled various 3C devices to communicate or operate with each other in a short range without wires or cables, so it was named "Bluetooth", and its charm was irresistible. When I named the technical standard of small-scale wireless communication developed by myself, I thought of King Harold, who fought everywhere. Its essence was to establish a universal radio air interface for the communication environment between fixed devices or mobile devices. 4GHz ISM (industry, this integration can stimulate the amazing consumption energy Harald Blatand, and the market share of Bluetooth products reached 2 in 24, in the era of high consumerism.
Bluetooth is an open global standard for wireless data and voice communication. Once the new technology is put on a fashionable coat, it is estimated that the sales volume will reach 2 million sets in 25. Among the mobile phones sold worldwide in 24, 5 million sets and IBM Huawei nova3i Bluetooth are connected to the car.
See if the Bluetooth of the mobile phone is searchable. If not, restart the mobile phone, enter the Bluetooth settings, click the device to be paired in the available devices, and re-click according to the screen prompts.
can't you find the car bluetooth device at present? It is suggested that you can clear all Bluetooth connection records and try to reconnect. In addition, Bluetooth can only connect to one similar device at a time, and you can restart the car and mobile phone devices and try to search again.
You can delete all the connected devices in the Bluetooth list of your mobile phone and try pairing again.
or delete all the historically connected devices from the car Bluetooth list and try pairing again.
It is recommended to back up the data and upgrade the latest system. What is the origin of Bluetooth?
The founder of Bluetooth is Ericsson of Sweden, which has carried out research and development as early as 1994. In 1997, Ericsson contacted other equipment manufacturers and aroused their strong interest in this technology. In February, 1998, five multinational corporations, including Ericsson, Nokia, IBM, Toshiba and Intel, formed a Special Interest Group (SIG), and their common goal was to establish a global small-scale wireless communication technology, namely Bluetooth.
the name of bluetooth comes from Harold blatand, the Danish king in the 1th century-translated into English as Harold Bluetooth (because he likes Lan Mei very much, his teeth are blue every day). In the preparatory stage of trade associations, an expressive name is needed to name this high-tech. Industry organizers, after a night of discussion about the history of Europe and the infinite technological development in the future, some people think that it is most appropriate to name it after King Blatand. King Blatand unified Norway, Sweden and Denmark. He is articulate and sociable, just like this upcoming technology, which will be defined as allowing coordination between different industrial fields and maintaining good communication between various system fields, such as computing, mobile phones and automobile industries. So the name was decided. The origin of the name BLUETOOTH
1. Concept: Bluetooth, a new wireless transmission method introduced in 1998, is actually a short-distance wireless communication technology that replaces data cables and realizes point-to-point or point-to-multipoint information exchange through low-bandwidth radio waves.
this network mode, also known PAN,PersonalAreaNetwork (pan), is based on a plurality of micro-networks or mini-networks constructed by exquisite Bluetooth master/accessory devices. Each micro-network consists of 8 active devices and 255 accessory devices, and a plurality of micro-networks are connected to form an expanded network, so that communication between various devices can be realized conveniently and quickly. It is an open standard to realize wireless transmission of voice and data, and it is a low-cost and short-distance wireless connection technology.
2. technical features: the features of bluetooth technology include: adopting frequency hopping technology to resist signal fading; Fast frequency hopping and short packet technology are adopted to reduce co-frequency interference and ensure transmission reliability; Forward error correction coding technology is adopted to reduce the influence of random noise in long-distance transmission; Use the ISM band of 2.4GHz without applying for a license; Adopt FM modulation mode to reduce the complexity of the equipment. The transmission rate of this technology is designed to be 1MHz, and full duplex communication is carried out in time division mode. Its baseband protocol is a combination of circuit switching and packet switching.
a synchronization packet is sent at a hop frequency, and each packet occupies one time slot, which can also be extended to five time slots. Bluetooth technology supports one asynchronous data channel or three concurrent synchronous voice channels, or one channel that simultaneously transmits asynchronous data and synchronous voice.
each voice channel supports 64kb/s synchronous voice; Asynchronous channels support asymmetric connections with a maximum rate of 721kb/s and a reverse response rate of 57.6kb/s, or symmetric connections with a rate of 432.6kb/s.. 3. Protocol: (1) Establishing a connection Before the piconet is established, all devices are in a ready state.
in this state, the unconnected device listens for messages every 1.28s Once the device is awakened, it listens for messages at the preset frequency of 32 hops. The number of frequency hopping varies from region to region, but the frequency of 32 frequency hopping is adopted by most countries.
the connection process is initiated by the master device. If the address of a device is known, the connection is established by using Page message; If the address is unknown, the connection is established by using the Inquiry message immediately following the page information.
in a piconet, devices without data transmission turn into energy-saving working state. The master device can set the slave device to hold mode, at this time, only the internal timer works; The slave device can also request to switch to the hold mode.
data transmission can be resumed immediately after the device is turned out from the holding mode. Hold mode is often used when connecting several piconets or managing low-power devices.
monitoring mode and sleep mode are two other low-power working modes. Bluetooth baseband technology supports two connection modes: connection oriented (SCO) mode, which is mainly used for voice transmission; Connectionless (ACL) mode, mainly used for packet data transmission.
(2) The error control baseband controller adopts three error detection and correction methods: 1/3 forward error correction coding (FEC); 2/3 forward error correction coding; Automatic repeat request (ARQ). (3) Authentication and encryption Authentication and encryption services are provided by the physical layer.
authentication is password-response. During the connection process, authentication may be required once or twice, or it may not be required. Authentication is an important part of any Bluetooth system, which allows users to add trusted Bluetooth devices by themselves. For example, only users' own laptops can communicate through their own mobile phones.
The purpose of Bluetooth security mechanism is to provide an appropriate level of protection. If users have a higher level of confidentiality requirements, effective transport layer and application layer security mechanisms can be used. (4) Bluetooth devices with software structure should be interoperable. For some devices, interoperability should be realized from radio compatibility module and air interface to application layer protocol and object exchange format. The requirements for other equipment (such as head-mounted equipment, etc.) are much looser.
The goal of the Bluetooth project is to ensure that any devices with Bluetooth tags can operate interchangeably. Software interoperability begins with the multiplexing of link-level protocols, the discovery of devices and services, and the segmentation and reassembly of packets.
Bluetooth devices must be able to recognize each other and identify the high-level functions supported by each other by installing appropriate software. Interoperability requires the same application layer protocol stack.
Different types of Bluetooth devices have different requirements for compatibility, so users can't expect the headset to contain an address book. The compatibility of Bluetooth means that it has radio compatibility, voice transceiving ability and the ability to find other Bluetooth devices, and more functions should be completed by mobile phones, handheld devices and notebook computers.
in order to realize these functions, the Bluetooth software architecture will make use of existing specifications, such as OBEX, vCard/vCalendar, HID (Humanized Interface Device) and TCP/IP, instead of developing new specifications. The compatibility of equipment requires that it can adapt to bluetooth profile and existing protocols.
4. Advantages: Bluetooth transmission is carried out by RF(2.4GHZ) carrier, so it has the basic characteristics of electromagnetic waves, has a large power, can increase the transmission distance, and has no angular and directional restrictions, has the ability to penetrate walls, and can be reflected, mirrored and diffracted between objects. Bluetooth is mainly used for short-distance transmission (up to 1 meters) of data and voice (1Mbps), with very low power consumption, and at the same time, it can connect many components with high transmission speed.
5. Disadvantages: Bluetooth is expensive; RF technology is susceptible to frequency interference; The protection setting of data security due to the characteristics of wall penetration; Bluetooth started relatively late, there is no clear and unified standard at present, and the compatibility problem has not been solved. The name of Bluetooth comes from the 1th century Danish King Harald Blatand- translated into Harold Bluetooth (because he likes eating Lan Mei very much, his teeth are blue every day).
In the preparatory stage of the trade association, an expressive name is needed to name this high-tech. Industry organizers, after a night of discussion about the history of Europe and the infinite technological development in the future, some people think that it is most appropriate to name it after King Blatand.
King Blatland unified Norway, Sweden and Denmark. He is articulate and sociable, just like this upcoming technology, which will be defined as allowing different industrial fields. Bluetooth connection car navigation is often disconnected. How to solve
hardware incompatibility?
method 1: most car-mounted DVD navigator devices have a RESET button on the panel, and some have a small hole (some are buttons), which is usually marked with reset next to it. Stick it in with a toothpick and press it for a few seconds, and the machine will shut down and restart.
method 2: for some machines, click settings in the main interface, and there is an option to restore factory settings, which is actually similar to the operation of mobile phones. Then re-pair the connection.
Bluetooth? ): is a wireless technical standard, which can realize the short between fixed equipment, mobile equipment and building personal area network.