Maximum PC - - WI-FI -

We’re talk­ing about wave­lengths here as an aside, be­cause the topic can dis­tract from the core is­sue of how wire­less data is trans­mit­ted. The wave­lengths used for public wire­less have been stan­dard­ized to the 2.4GHz and 5GHz bands; think of these as the “ca­bles” used to trans­mit the data.

The 2.4GHz wave­length has been key, be­cause it’s an all-im­por­tant wave­length that, in most of the world, is an open un­li­censed fre­quency. Why is that im­por­tant? The 802.11a stan­dard was adopted in the United States, and was based on a 5GHz wave­length. Able to trans­mit twice the amount of data as 2.4GHz, there were strong moves to have 5GHz the de facto wave­length at the end of 1999.

The prob­lem at the time was that out­side of the States and Ja­pan, the 5GHz range usu­ally re­quired a li­cense; in some re­gions, it was re­stricted for mil­i­tary use. Both fac­tors de­layed re­lease and greatly in­creased the cost. This changed in 2003, when the fre­quency was freed up in Europe, due to the in­creas­ing de­mands be­ing put on the 2.4GHz range, but by then, it was too late for 802.11a, be­cause far cheaper and eas­ier-to-im­ple­ment 802.11b and g gear had swamped the mar­ket. Another trou­ble­some as­pect is that the 5GHz fre­quency is more read­ily ab­sorbed by walls, cut­ting the work­ing dis­tance dra­mat­i­cally, and negat­ing most of the speed ad­van­tages. The truth is, with ra­dio waves, it’s not their speed that mat­ters, it’s what you do with them that counts. But for 5GHz, its ad­van­tages would come back around….

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