Wireless Networking

Wi-Fi is an extension of the LAN to the wireless domain (WLAN). Wi-Fi technology has simplified the installation and distribution of networking infrastructure by replacing wire cabling with low-power radio waves. Because it is standards-based, it is widely available and integrates seamlessly with existing Ethernet networks. For wireless data acquisition, Wi-Fi is an easy way to tie into existing corporate infrastructure without special gateways or converters. With the most current ratified IEEE standard, IEEE 802.11g, it also provides ample bandwidth (54 Mb/s) for streaming dynamic waveform data.

Figure 3. Adding Wi-Fi connectivity to a wired network requires a wireless access point, such as the NI WAP-3701.

Security is foremost on the minds of network administrators when implementing Wi-Fi in a corporate environment. Because Wi-Fi transmits data over radio waves, there are few means for physically restricting network access. Generally speaking, there are three levels of wireless security, all of which are supported by NI Wi-Fi DAQ. The three levels are Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), and Wi-Fi Protected Access 2 (WPA2, also known as IEEE 802.11i). WEP is considered too weak for almost all IT networks; most use WPA or WPA2 instead. The differences between these standards are in how they implement the two key components of wireless security – encryption and authentication.

Security Standard	Encryption	Authentication
WEP	64-bit key (RC4 cipher)	64-bit key
WPA	128-bit TKIP (RC4 cipher)	802.1X and EAP
WPA2 (IEEE 802.11i)	128-bit AES	802.1X and EAP

Table 1. There are three levels of Wi-Fi network security to consider when implementing Wi-Fi in a corporate environment.