Introduction
WiFi is a set of standards surounding wireless networks commonly used for both personal and commercial use. These standards allow computers, cameras and other devices to communicate with one another - either locally or across the Internet. This provides a host of powerful capabilities for Photographers, from transmitting images to controlling cameras.
These standards are governed by the
IEEE 802.11 working groups and encompass a number of different protocols used for various applications. The details of these standards are covered in the following sections, please read ahead to learn more.
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Oversight
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WiFi Aliance
A non-profit organization made up of companies using the WiFi standards, the WiFi aliance oversees the testing and certification of new equipment. As it holds the trademarks on the names and logos used to identify WiFi devices, they ensure that companies comply with the contents of the underlying standards.
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IEEE
The standards organization that oversees the technical standards added into the WiFi family. While it doesn't manage the day-to-day matters, the
IEEE oversees the process of developing and ratifying new ammendments added to the standard.
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Revisions
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IEEE 802.11 Legacy
Ratified in 1997, the original
IEEE 802.11 standard provided a new wireless networking protocol. This standard provided data rates of up to 2mbps over either Infrared or
2.4GHz Microwave channels. It would go on to become the foundation for a family of different standards (
802.11b/
a/
g/etc.).
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IEEE 802.11b
Ratified in 1999,
802.11b was the first standard in the family to become popularized. By using the same underlying techniques as the original
802.11 standard, it allowed mature products to reach the market very quickly after ratification. The significant increase in speed and more rigid requirements helped to push adoption and allowed
802.11b to usher
WiFi into the mainstream.
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IEEE 802.11a
Ratified in 1999 (shortly after
802.11b), the
802.11a standard added a new coding technique and operated on the
5GHz band. This allowed it to run at much higher speeds (54mbps) and provided a much larger range of channels to work with. This standard was originally intended to get
WiFi out of the increasingly crowded
2.4GHz band and form the foundation of future revisions.
Unfortunately,
5GHz radio equipment was limited at the time of its ratification so it took until 2001 before mature products appeared on the market. By this time,
802.11b had become firmly entrenched in the mass market so the fact that the two standards were not compatible meant that migration to
802.11a was limited.
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IEEE 802.11g
Ratified in 2003,
802.11g added a significant increase in throughput to the older
802.11b standard. Unlike the earlier
802.11a revision,
802.11g maintains backward compatibility with
802.11b as it uses the same
2.4GHz band. It has since replaced
802.11b as the dominant standard and is used in the majority of modern
WiFi equipment.
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IEEE 802.11n
Still in the ratification process, this next generation protocol incorporates new technology to significantly boost throughput and range. This will allow the use of wireless networks for high-bandwidth tasks that are impractical with existing standards.
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Comparison Table *Number of
Non-Overlapping channels listed. The
WiFi variants running on the
2.4GHz band use a staggered channel arangement where adjacent channels overlap one another.
** The
802.11n standard provides optional support for the
5GHz band.
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Settings
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SSID - Service Set IDentifier
The
service set identifier is a unique name that identifies a wireless network. This is used by wireless clients to find and connect to the appropriate network. As such, the
SSID must be entered accurately on all devices - any mistakes, regardless of how minor, will cause the connection process to fail.
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Channel
This setting selects the frequency that the wireless network will operate on. As only one network can operate on a frequency at any given time, this control can be used to work around other wireless devices in the area. The available options depend critically on the WiFi standard in use, so users should see the specific articles for more information on this topic.
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Infrastructure vs. Ad-Hoc
Conventional wireless networks will typically be used in
Infrastructure mode where the network is anchored around one or more
Access Points. These
APs act as central arbiters and manage both the wireless devices and their interaction with a wired network.
Alternately, WiFi networks can also operate in an
ad-hoc mode that allows devices to connect directly with one another. This can be useful when in the field, as it requires nothing more than the two devices that need to communicate.
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Security
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WEP - Wired Equivalent Privacy
As a wireless network broadcasts information over the airwaves, it is an inherently insecure method of transmission. To help combat this, the original
802.11 standard provided an encryption scheme called
WEP in an attempt to make it difficult for malicious users to gain access to this data. While it does add some overhead (slowing data transfers slightly), it helps to protect any sensitive data from third parties trying to gain access.
Unfortunately, this standard was found to have a number of flaws that made it possible for attackers to circumvent the encryption and gain access to the data. While it still requires enough effort to deter casual snooping, it is possible for a determined attacker to break through this encryption.
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WPA - WiFi Protected Access
Created as an intermediate response to the flaws in
WEP,
WPA provides a stronger form of encryption to help protect personal networks. It implemented a subset of
IEEE 802.11i, which allowed it to be brought to market prior to the ratification of the official standard. While its protection is not as strong as
WPA2,
WPA is compatible with a much larger complement of WiFi equipment.
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WPA2 / 802.11i
Implementing all of the mandatory components of
IEEE 802.11i,
WPA2 is a more secure form of encryption than either previous standard. As this is a relatively new standard, support is generally limited to the latest generation of products.
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MAC Filters
A basic security precaution,
MAC filters maintain a list of adapters allowed to access the wireless network. If an adapter not on the list attempts to connect to the wireless network, the access point will reject its requests. Unfortunately, as the hardware addresses on network cards can be changed so this provides only minimal protection against casual attackers.
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See Also [
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External Links 
Linear Mode
