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Equipment that runs wireless networks is made to be compatible with one or more wireless specifications so that products from different manufacturers can be interoperable. Wireless-N is a newer specification than wireless-G, and has some key advantages over the older protocol. The newer specification can operate on a wider frequency band, is faster and more robust. Wireless-N is also referred to under its numerical classification of 802.11n, while the predecessor, wireless-G is 802.11g. The 802.11 wireless classification and its respective flavors, designated by the trailing letter, are published by the Institute of Electronic and Electrical Engineers (IEEE).
The top speed of a standard wireless-G network is 54 Megabits per second (Mbps), though real-world speeds are somewhat slower. Super-G or Xtreme G, a hybrid of 802.11g, boasts 108 Mbps, but this requires proprietary hardware. The standard 54 Mbps is actually still quite fast when one considers the average Internet connection is capped at 1-5 Mbps. Premium DSL, cable and fiber optic Internet might offer speeds between 10-50 Mbps, still within the capabilities of the network. For the average person and business, however, top-end network speeds will only be achieved and appreciated when sharing files between local machines.
Wireless-N incorporates MIMO (multiple-input, multiple-output). MIMO utilizes multiple antennas that transmit and receive several “special streams” of data concurrently. As a result, speeds can reach 450 Mbps using three special streams, with 600 Mbps being the theoretical maximum using four special streams. This assumes each stream is using a band 40 MHz wide, and these specifications refer to the 802.11n-2009 finalized standard.
Prior to IEEE finalization in September 2009, 802.11n had been in development for several years. Products manufactured during this period are compliant with wireless-N draft standards, with theoretical speeds of 300 Mbps. Real-world speeds are closer to 130-180 Mbps, though this varies due to the different flavors of 802.11n and eccentricities of compatibility between hardware. A wireless-N draft router might be upgradeable to 802.11n-2009 via a BIOS flash, depending on the manufacturer.
Wireless-N is not backward compatible with wireless-G. The latter operates on the 2.4 GHz band, while “true” 802.11n uses the 5 GHz band, though it can operate in 2.4 GHz with a hit to performance. The switch is more desirable because of the number of gadgets operating in the 2.4GHz band, which can potentially introduce interference. Some examples include microwave ovens, many types of cordless and cellular phones, surrounding 802.11g networks, and Bluetooth® networks.
A router might contain radios for both bands, offering support for 802.11g and 802.11n, but operating in mixed mode degrades wireless-N performance. For the network to fully realize N-advantages, all equipment must be 802.11n-2009 compliant, operating in the 5 GHz band.
Many factors influence the effective broadcast range of a wireless network, including network hardware, configuration, building materials in the surrounding structure(s), and topography in the case of outdoor networks. Signal integrity also degrades over distance. The indoor range of the 802.11n-2009 finalized standard might be approximated at 300-feet (91m) indoors, and up to 850-feet (259m) outdoors, but results vary. This compared to wireless-G at approximately 150 feet (46m) indoors and 300 feet (92m) outdoors. Extenders and other technologies can be used to broaden network range when necessary.
People or businesses that only maintain a wireless network to share a standard Internet connection will not notice a difference between wireless-N and wireless-G, unless adverse conditions are degrading wireless-G performance that would not be factors in a wireless-N network, such as interference on the 2.4 GHz band. Other reasons to switch over would be for deeper broadcast range, or to share an ultra-fast Internet connection.
Those who share files wirelessly between local machines can benefit tremendously from upgrading to a wireless-N network, realizing far faster transfer rates, improving productivity and saving time. The router and all network cards or adapters should be compliant with the 802.11n-2009 — or most recently finalized — specification to ensure the best results and to future-proof the investment.