This is the second instalment in a series of blogs covering the history of Wi-Fi®. This part will look at how the technology has progressed to the high speed connection we know today.
By the early years of the new millennium, Wi-Fi quickly had started to gain widespread popularity, as the benefits of wireless connectivity became clear. 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. Home users, many of whom were starting to get broadband Internet, were able to easily share their connections throughout the house.
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.
The advent of 802.11b, in 1999, set the stage for Wi-Fi mass adoption. Its cheaper price point made it accessible for consumers, and its 11 Mbit/s speeds made it fast enough to replace wired Ethernet connections for enterprise users. Driven by the broadband internet explosion in the early years post 2000, 802.11b became a great success. Both consumers and businesses found wireless was a great way to easily share the newfound high speed connections that DSL, cable and other broadband technologies gave them.
As broadband speeds became the norm, consumer’s computer usage habits changed accordingly. Higher bandwidth applications such as music/movie sharing and streaming audio started to see increasing popularity within the consumer space.
Meanwhile, in the enterprise market, wireless had even greater speed demands to contend with, as it was competing with fast local networking over Ethernet. Business use cases (such as VoIP, file sharing and printer sharing, as well as desktop virtualization) needed to work seamlessly if wireless was to be adopted.
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).
To address speed concerns, in 2003 the IEEE 802.11 working group came out with 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. Even after speed decreases due to protocol overhead, its theoretical maximum of 31.4 Mbit/s was enough bandwidth to accommodate increasingly fast household broadband speeds.
Actually 802.11g was not the first 802.11 wireless standard to achieve 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. That fact, along with more expensive equipment, meant that 802.11a was only ever popular within the business market segment and never saw proliferation into the higher volume domestic/consumer arena.
By using 2.4 GHz to reach 54 Mbit/s, 802.11g was able to achieve high speeds while retaining full backwards compatibility with 802.11b. This was crucial, as 802.11b had already established itself as the main wireless standard for consumer devices by this point. Its backwards compatibility, along with cheaper hardware compared to 802.11a, were big selling points, and 802.11g soon became the new, faster wireless standard for consumer and, increasingly, even business related applications.
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.
802.11n offered significantly faster network speeds. 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).