The wireless network is the wireless local area network (WLAN) that does not need a network cable, using radio waves as the medium of information transmission, similar to the use of wired networks, the biggest difference lies in the difference in the transmission medium, the use of radio technology instead of a network cable, which can be used as a backup for each other and the wired network.
1, Common wireless network (WIFI) cards include CDMA, GPRS and CDPD, etc.
CDMA short for Code Division Multiple Access, allows all users to use all frequency bands.
CDMA short for Code Division Multiple Access, allows all users to use all frequency bands.
GPRS short for General Packet Radio Service, using packet switching technology, with real-time on-line, according to the amount of billing, high-speed and fast characteristics.
CDPD short for Cellular Digital Packet Data, using packet data model, widely used in public data communication projects, such as: mobile office, finance, transportation, etc.
2, There are three common Transmission standards for wireless network:
IEEE 802.11a: using the 5GHz band, transmission speed of 54Mbps, incompatible with 802.11b.
IEEE 802.11b: using the 2.4GHz band, transmission speed 11Mbps
IEEE 802.11g: Uses 2.4GHz band, transmission speed 54Mbps, backward compatible with 802.11b.
IEEE 802.11b is currently the most commonly used, but IEEE 802.11g is the next generation standard.
There are also IEE 802.11ac, IEE802.11ax transmission standard for higher speed Wireless devices.
3,Types of Wireless network cards interfaces:
One is the PCI interface wireless network card for desktop computers.
One is PCMCIA interface wireless network card for notebook computers.
Another one is USB wireless network card, this kind of network card whether desktop users or notebook users, as long as the installation of the driver, can be used.
When choosing a wireless card, you should note that only the wireless card with USB2.0 interface can meet the needs of 802.11g or 802.11g+. In addition to USB wireless cards, there are also MINI-PCI wireless cards that are more widely used in notebook computers. MINI-PCI is a built-in wireless network card. The advantage is that it does not require a PC card or USB slot and eliminates the need to carry a PC card or USB card with you at all times. The price difference between these wireless cards is small, and the performance/functionality is similar, so you can choose according to your needs.
4, Transmission speed of different wireless networks:
From the speed point of view, the mainstream rate of wireless network , from 54M, 150M, 300M, 450M, to 600M, it has a lot to do with the performance and the environment.
For example:
54Mbps: Its WLAN transmission speed is generally between 16-30Mbps, which translates to MB or about 2MB-4MB per second. Taking the middle value of 3MB, it takes about 35 seconds to transfer a 100MB file at this speed, and at least 4 minutes to transfer a 1GB file.
108Mbps: Its WLAN transmission speed is generally between 24-50Mbps, which is converted into MB, meaning that the transmission speed is around 3MB-6MB per second. Taking its middle value of 4.5MB, it takes about 25 seconds to transfer a 100MB file at this speed.
5， What’s the advantage of the wireless network card?
1, Easy to take, small, convenient to use. There is few limit for the location area.
2, The wireless network card with built-in card slot, as long as we put a usim card, we can use it immediately.
6, What’s the disadvantage of the wireless network card?
- The built-in devices are troublesome to install, and the terminal equipment needs to be disassembled, so the heat dissipation effect is not good. External products are easy to damage the equipment, and the antennas of some wireless network cards are built-in, so it is inconvenient to adjust the direction of the antennas.
- The wireless network card is not as stable as a professional router, and has a very limited number of clients.
3. the tariff is higher, which is much more expensive than broadband, and many wireless network cards do not have voice call function, and can only be used to send text messages or surf the Internet.
- The network speed is slow, generally only 3G or 4G networks can be connected, and the bandwidth is only about 2M-4M.
Anyway, for those persons who is always on business trip or outdoor working, or travelling frequently, the wireless network card is still a nice choice.
Note: The point of this article may not precise. If you have any ideas about the wireless networks, please feel free to share.1
