Modern communication technology is moving towards network core technology packetization and narrowband access technology wireless. In the field of wireless access, early adopters of circuit-based transmission and packet transmission technology, the Bluetooth special interest group SIG, which is composed of Ericsson, Intel, Nokia, Toshiba and IBM, recently launched the Bluetooth program. Bluetooth is gradually becoming a rookie in the field of data transmission with its small size, low cost and strong penetrability. It adopts Bluetooth technology to realize wireless transmission in the automatic fire alarm system, which has the advantage that other technologies can't match.
This article refers to the address: http://
Introduction to Bluetooth technology
"Bluetooth" technology is the open standard for general-purpose wireless signal transmission interfaces and their manipulation software, and is a technical specification with a low form factor for short-range wireless connection devices. Its purpose is to make the network ubiquitous, that is, to replace the existing network connection with wireless technology, so that the hardware produced by different manufacturers can have the possibility of interactive information and cross operation in a short range under the condition of wireless connection. It is based on a low-cost, short-range wireless connection that provides a common interface to existing digital networks and peripherals to form a special connected device group for long-distance fixed networks and to transmit between two electronic devices using radio waves. Data or other digital form of content.
The Bluetooth system consists of four functional units: wireless unit, link control unit, link management, and software function. The core technology is a microchip group consisting of baseband and RF chips with a size of 9mm×9mm. The baseband chip performs simple digital information processing through a built-in wireless communication protocol, allowing different Bluetooth products to exchange data; the RF chip is responsible for transmitting signals. Bluetooth technology emphasizes small size, low power, low unit price, and supports point-to-point and point-to-multipoint connections. We usually refer to all devices connected by Bluetooth technology as a piconet. Several piconets can be connected together to identify each piconet in frequency hopping order. All users of the same piconet are synchronized with this frequency hopping sequence. The topology can be described as a "multi-piconet" architecture in which the full-duplex data rate can exceed 6 Mb/s with 10 full-load independent piconets.
Modern communication technology is moving towards network core technology packetization and narrowband access technology wireless. In the field of wireless access, early adopters of circuit-based transmission and packet transmission technology, the Bluetooth special interest group SIG, which is composed of Ericsson, Intel, Nokia, Toshiba and IBM, recently launched the Bluetooth program. Bluetooth is gradually becoming a rookie in the field of data transmission with its small size, low cost and strong penetrability. It adopts Bluetooth technology to realize wireless transmission in the automatic fire alarm system, which has the advantage that other technologies can't match.
Other features of Bluetooth:
1. Bluetooth works in the internationally open 2.4GHz ISM (ie, industrial, scientific, medical) frequency band. In this frequency band, the user does not need to apply for the frequency of access to the special management organization;
2. Using frequency hopping spread spectrum technology, the frequency difference between 2.4GHz and 2.4835GHz is divided into 79 frequency points. According to the hopping frequency determined by the main unit of piconet, the random sequence is 1600 hops per second, so that the wireless link itself has more High safety and anti-interference ability;
3. Transmission distance. The current working distance is less than 10 meters, and can reach 100 meters after increasing the RF power. This range of work enables Bluetooth to guarantee a high data transmission rate while reducing the interference of other electronic products and radio technologies, which is beneficial to the security of the system;
4. The modulation mode adopts GFSK, BT=0.5, positive frequency offset indicates 1, and negative frequency offset indicates 0;
5. Using time division multiplexing multiple access technology, each Bluetooth device transmits data in time slot in the form of data packets in its own time slot, which can effectively avoid problems such as "collision" and "hidden terminal" in wireless communication;
6. Supports two types of connection: synchronous directional connection (SCO) and asynchronous connectionless (ACL). Both connection types use TDD (Time Division Duplex Transmission Scheme) to achieve full duplex transmission;
7. The baseband controller uses three error correction schemes to achieve error-free transmission of data;
8. The air interface is based on an antenna level of 0 dBm and follows the FCC (Federal Communications Commission) standard for the ISM band with a level of 0 dBm;
9, in line with the specification of the Bluetooth 1.0b version: the software version is re.1.08, and the hardware version is DIG8043390.
Car Battery Test Pen ,Car Battery Tester ,Digital Circuit Test ,Electric Circuit Test
YINTE TOOLS (NINGBO) CO., LTD , https://www.yinte-tools.com