Early computers generally used a 5.25-inch floppy drive, and there were two main 5.25-inch floppy drives. A 5.25-inch double-sided high-density floppy drive (also known as 5.25-inch 1.2M floppy drive), can read and write 5.25-inch double-sided high-density floppy disk (1.2M), 5.25-inch double-sided low density floppy disk (360K), 5.25 inches single low density Floppy disk (180K). The other is a two-sided low density floppy drive, the main difference with the former is the inability to read and write 5.25 inches double-sided high density floppy disk (1.2M). Later it produced a 3.5-inch double-sided high-density floppy drive (also known as 3.5-inch 1.44M floppy drive), and can read and write 3.5-inch double-sided high-density floppy disk (1.44M) and 3.5-inch single-sided high-density floppy disk (720K). For a long time, the computer generally has two floppy drives, which are respectively a 5.25-inch 1.2M floppy drive and a 3.5-inch 1.44M floppy drive. Now it is generally only equipped with a 3.5-inch 1.44M floppy drive. The common floppy drive is characterized by small capacity, high cost per unit of capacity, floppy disk error-prone, poor reliability, and slow speed. Notebooks generally use a built-in 3.55" 1.44MB floppy drive or an external floppy drive. Dual frequency band refers to the characteristic that the same communication device can work in two frequency bands. There are many applications, such as dual-band routers. A dual-band router refers to a router that supports two channels, one 2.4G channel and one 5G channel. Generally, routers are designed to be 2.4GHZ, so there will be mutual interference between signals in the same area. At this time, if you choose the 5.GHZ frequency band mode, it will effectively avoid signal interference in these frequency bands, and wireless signals will be transmitted accordingly. farther. 5.0G WIFI XPON ONU, 2.4G+5.0G WIFI XPON ONU, WIFI XPON ONU with 2.4G and 5.0G, XPON ONU with Dual Band, Dual Band WIFI XPON 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.
Floppy drive
The world's first 5.25-inch floppy drive was developed by Shugart Associates in 1976 for IBM's mainframe. It was later used in IBM's early PCs. In 1980, Sony introduced a 3.5-inch disk. By the early 90's, 3.5-inch, 1.44-MB floppy disks have been used for standard data transmission methods for PCs.