This is the second instalment in a series of blogs covering the history of Wi-Fi®. While the first part looked at the origins of Wi-Fi, this part will look at how the technology has progressed to the high speed connection we know today.
Wireless Revolution
Hotspots began popping up at coffee shops, airports and hotels as businesses and consumers started to realize the potential for Wi-Fi to enable early forms of what we now know as mobile computing.
Thanks to the IEEE® 802.11 working group's efforts, a proprietary wireless protocol that was originally designed simply for connecting cash registers (see previous blog) had become the basis for a wireless networking standard that was changing the whole fabric of society.
As broadband speeds became the norm, consumer's computer usage habits changed accordingly.
Even in the early 2000's, the speed that 802.11b could support was far from cutting edge. On the wired side of things, 10/100 Ethernet was already a widespread standard. At 100 Mbit/s, it was almost 10 times faster than 802.11b's nominal 11 Mbit/s speed. 802.11b's protocol overhead meant that, in fact, maximum theoretical speeds were 5.9 Mbit/s. In practice though, as 802.11b used the increasingly popular 2.4 GHz band, speeds proved to be lower than that still. Interference from microwave ovens, cordless phones and other consumer electronics, meant that real world speeds often didn't reach the 5.9 Mbit/s mark (sometimes not even close).
802.11G
Though 802.11g would use the 2.4 GHz frequency band just like 802.11b, it was able to achieve speeds of up to 54 Mbit/s.
That crown goes to 802.11a, which had done it back in 1999. However, 802.11a used a separate 5.8 GHz frequency to achieve its fast speeds. While 5.8 GHz had the benefit of less radio interference from consumer electronics, it also meant incompatibility with 802.11b.
This was crucial, as 802.11b had already established itself as the main wireless standard for consumer devices by this point.
802.11n
Introduced in 2009, 802.11n made further speed improvements upon 802.11g and 802.11a. Operating on either 2.4 GHz or 5.8 GHz frequency bands (though not simultaneously), 802.11n improved transfer efficiency through frame aggregation, and also introduced optional MIMO and 40 Hz channels - double the channel width of 802.11g.
At the low end, if it was operating in the same type of single antenna, 20 Hz channel width configuration as an 802.11g network, the 802.11n network could achieve 72 Mbit/s. If, in addition, the double width 40 Hz channel was used, with multiple antennas, then data rates could be much faster - up to 600 Mbit/s (for a four antenna configuration).
The third and final blog in this series will take us right up to the modern day and will also look at the potential of Wi-Fi in the future.