Global wireless networks differ from the WWAN Wireless LAN WLAN what data they use wireless technology provider , such as UMTS , GPRS ,CDMA2000 , GSM , CDPD , Mobitex , HSDPA , 3G or WiMAX (although the last right attitude to WMAN - metropolitan area wireless networks). The services are proposed, usually for a fee by operators of regional, national or even global scale. WWAN technology enables the user, for example, a laptop and WWAN- adapter to access the World Wide Web , use e-mail and connect to the virtual private networks from anywhere within the coverage of a wireless carrier. Many modern laptops have built-in adapters WWAN (eg, HSDPA ).
In terms of switching data networks WWAN networks can be built on the following principles:
- packet switched ( GPRS );
- circuit switching ( CSD , HSCSD ).
As wireless network can not provide a physically secure channel data transmission, WWAN networks for security, as a rule, different mediaencryption and authentication . These security measures should not, however, be overestimated, because there are cases of successful hacking of certain encryption keys for wireless networks, and the possibility of breaking key GSM grounded theory. However, cases of hacking keys UMTS (3G) is not known.