无线上网卡什么是无线上网卡(我需要什么无线上网卡)（What is a wireless network card (what wireless network card I need)）

什么是无线上网卡(我需要什么无线上网卡) What is a wirelessnetwork card (what wireless network card I need) What is awireless network card (what wireless card I need) , .Txtis smoke, but loneliness. . . . . . Not you do not smile, a smilepowder fall! People are not smart, but also learn to bald others.If you can't tie my heart, don't say I'm a playboy! No matterhow outstanding Chopin, also can not play Lao Tzu sadness! Behappywhen you're alive, because we're going to die a long time.Please don' t speak English in front of me, OK?What is awirelessnetwork card? What wireless adapter do I need?

1) generally agreed that the "wireless card" and "wirelessnetwork card" is different, although the literal meaning doesnot seem to distinguish.

2) the purchase of "wireless network card", you need todetermine whether you want CDMA or GPRS, in the country, theformer is China Unicom support, which is supported by ChinaMobi le.

3) the purchase of a wireless network card is usually a desktopcomputer, or an old one without abuilt-inwireless network card.Now the general selection of stability, while supporting IEEE,

802. 11g, IEEE, 802. 11b two standards on the OK, and the priceis also very cheap.

In a word, wireless internet access means that you can surf theInternet without inserting a network cable. That is, you canuse electromagnetic waves instead of cables to transmitsignals.

But specific to the wireless Internet technology at this stagein the transition period, so a lot of things, let us ordinarypeople (the non professional engineering and technicalpersonnel) feel confused, I can help you "reason", we hope tohelp.

Current (March 2008) domestic access, common wireless internetaccess, there are 3 main:

1) using a wireless network or mobile Unicom, mobile phone canplay where you can surf the Internet, the greatest degree of"getridof theshacklesof the line"; this is "base++wirelessLAN card charges", or "wireless LAN" can be replaced with"mobile phone + data line".

2) theuse of awireless routerwithinahome or school dormitoryenables you to get rid of the "line" constraint within a shortdistance; this is a router +wireless card + broadband fee".

3) Internet access through cafes, hotels, airports, internaldepartments of the WIFI hot spots. More fashionable is themetropolitan area network, for example, recently deployed inBeijing, covering five rings within thewireless WIFI network,allowing users to achieve wireless access within a wide rangeof the internet. Thismethod is "AP (AccessPoint, accesspoint)+ wireless network card", which is free to users.

The above 1) need to use the "wireless network card", "2" and"3") in general a "wireless network card" on it, the newnotebook is now generally built-in wireless network card, and

even the purchase of the province.

General agreement "wireless LAN" is "router +wireless card"or "hot +wireless card"mode and "wireless LAN" (the "Shang")is through the Unicom mobile wireless network to realize theInternet or network card. The former is not through mobile orUnicom Network, but through to telecom or Netcom broadband feeto use their cable network, just a short distance wirelessrouter, cable network still go after.

"Internal wireless network card chip" and "wireless LAN" iscompletely different, the former is the modem chip GSM or CDMA,the latter is to adjust the demodulation chipof 802. 11 wirelessLAN, communication in different ways, like a man to speak Frenchand one person said Shaanxi words, no communication.

The most striking feature here is the frequency ofcommunication. The difference between them is also the natureof the frequency of communication, so the standards aredifferent.

1) "the wireless network card is the use of mobile or Unicommobile service providers this network, it go communicationmobile phone, China Mobile GSM network frequency is 900MHz,1800MHz (1.8GHz) , China Unicom' s CDMA is 824.01-848.97MHz/869.01-893.97MHz. They follow the GSM or IS-95 standards.At present, for Unicom, it is CDMA 1x network card (that is oftensaid on the CDMA network card) , for mobile, it is GPRS networkcard. GPRS is awireless Internet device based onChina Mobile' sGSM network. GPRS English called"General Packet Radio Service",

meaning "Chinese general packet radio service", it is the useof "packet switching" (Packet-Switched) concept to develop awireless transmission mode.

2) and the family or school "wireless router" supporting theuse of "wireless network card" to follow the IEEE 802. 11gstandard, the highest speed is 54Mbps, the working frequencyband 5 GHz.

3) WiFi hotspot follow the 802. 11b standard, the highest rateis 11Mbps, the working frequency is 2.4GHz; the so-called"Centrino technology" is based on the standard. In this way,as long as the wireless internet access laptop or PDA to gethot coverage area, you can access the Internet at high speed.According to the signal strength, the system will adjust thetransmission rate to 5.5Mbps, 2Mbps and 1Mbps bandwidth (whenthe signal is strong, 11Mbps, weak 1Mbps) .

Here is easy to confuse the 2) and 3) , we are using "wirelessLAN", why is to a wireless router and the other one is the famous"WiFi", one is 802. 11g and another is 802. 11b? In fact, thisis related to the electromagnetic wave transmissioncharacteristics and the difficulty of communication. You mayhave noticed that the "wireless" in the most complete, mostwireless Internet free China Mobile or China Unicom' s wirelessnetwork card "is the lowest, but the highest 100 K, but alsois a very strong signal; and the highest rate of 54Mbps, throughthe 3 wall distance is enough. 802. 11b standard although thehighest speed is 11Mbps, a little lower, but the effectivecommunication distance is much higher, covering a hotel,airport, a building is no problem.

To achieve 2) and 3) Internet access, as long as there is awireless network card of the machine, you can, the machinebuilt-in or buy. Buy a wireless card such as the common TP-LINKTL-WN322G+ also supports "IEEE 802. 11g, IEEE 802. 11b"agreement (manufacturers also marked "CSMA/CA with ACK"protocol support is not the same, IEEE 802. 11g IEEE 802. 11b tiedto the commercial standard, but a technical standard,

Carrier sense multiple access / collision avoidance,

CSMA/CA<with, Collision, Avoidance>) . The Intel 3945ABGwireless card supports both 802. 11b (2.4GHz/11Mbps) , 802. 11a(5GHz/54Mbps) , and 802. 11 g (2.4GHz/54Mbps) .

Future imagination:

1) 3G (third generation < mobile communication >)

Suggest you buy now the wireless network card is not expensive,because this old slow, this is used to call the network on theInternet, is expensive and slow, it is hard for.

Stop, do not buy now known as support for 3G wireless networkcard, because it may only support CDMA2000 or WCDMA, thedomestic can not be used, the domestic 3G will be TD-SCDMA.But 3G is lucky for users who like wireless Internet access.Because 3G is prepared to some extent for you. 3G is theevolution version of GPRS and CDMA, to tell you the truth, thespeedhasbeenveryfast, andthemost critical is theoldsaying:"you can use the phone where you can access the Internet. ".

2) WiMax

What? Is it still expensive to use 3G? Or complain about thespeed of downloading? No school 100M LAN, online movie cool?That' s out of the question. It' s only with WiMax, because it' sfor the person you're so picky about and willing to spend moneyon. WiMax is, to some extent, the evolution version of WiFi.The speed is faster than before, and the coverage is wider thanbefore (you can hardly believe it, and even become a powerfulcompetitor of 3G) .