6. Wi-Fi
6.1 Introduction to Wi-Fi for WLANs
Wi-Fi is a technology that allows data transfer among electronic devices using specific radio
frequencies over a wireless local area network (WLAN). A wireless network is like a wired network,
except it uses radio waves just like cell phones, televisions, and other radios. Over-the-air speeds
vary depending on protocol, distance, and network activity. When using the NL241, please note
that your total throughput to the data logger will generally be governed by the speed of serial
communications.
Wi-Fi transmits at frequencies around 2.4 and 5 GHz (the NL241 only uses 2.4 GHz). The high
frequency allows fast rates but reduced communications distance. These frequencies can be used
by anyone and do not require a license from the FCC to use or transmit (unlike most UHF and
VHF frequencies) as long as certain power levels are maintained.
The NL241 supports the 802.11b, 802.11g, and 802.11n wireless network standards.
The NL241 also supports several wireless security protocols. These include WEP (Wired Equivalent
Privacy), WPA (Wi-Fi Protected Access) (personal), WPA2 (Wi-Fi Protected Access II) (personal),
and WPA/WPA2-Enterprise. These security protocols allow network traffic to be encrypted and
help protect data transmitted over the Wi-Fi network.
TIP:
WEP is an old technology and is not secure. We recommend that you configure your
networks to use WPA2 technology.
6.2 Wireless network modes
6.2.1 Join a network
The NL241 can be configured to join an already established infrastructure wireless network
(WLAN) (see
(p. 16)). An infrastructure wireless network is one in which all devices or
stations (STA) communicate through an access point (AP). This AP will typically connect the
wireless network (and the NL241) to a larger wired company or home network and/or the
internet. The AP device also controls and routes all the traffic on the wireless network. Once the
NL241 has successfully joined the existing wireless network, it can communicate with other
devices on the network.
NL241 Wireless Network Link Interface
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