Wi-Fi
When Norman Abramson launched the ALOHAnet project at the University of Hawaii in the 1970s, he probably had no idea he would transform our daily relationship with information. This experiment, which involved linking computers via radio waves across the Hawaiian islands, demonstrated that data could be transmitted without cables.
Things accelerated in 1985 when the Federal Communications Commission, under the impetus of Michael Marcus, authorized free use of certain frequency bands: 902-928 MHz, 2.4-2.4835 GHz, and 5.725-5.850 GHz. These ISM (Industrial, Scientific and Medical) bands, initially reserved for industrial and medical uses, became the playground for consumer wireless technologies. Other countries followed suit.
The first IEEE 802.11 standard appeared in 1997, with a modest throughput of 2 Mbit/s on the 2.4 GHz band. But it was Apple that truly popularized the technology with the general public in 1999, by integrating Wi-Fi into its AirPort base station and iBook laptop. These devices used the IEEE 802.11b standard, which reached 11 Mbit/s. The name “Wi-Fi,” created by a marketing agency, actually has no particular technical meaning, despite its phonetic similarity to “Hi-Fi.”
The technical architecture of Wi-Fi draws directly from work on the ALOHA protocol. The CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) principle allows a radio channel to be shared among multiple devices without constant interference. Research by Kleinrock, Tobagi, and Lam at UCLA helped refine these medium access mechanisms, adapted to the specific constraints of radio communications.
Standards then followed in rapid succession. IEEE 802.11a introduced OFDM modulation and the 5 GHz band in 1999. In 2003, IEEE 802.11g brought 54 Mbit/s to the heavily congested 2.4 GHz band. The real breakthrough came in 2009 with IEEE 802.11n and MIMO technology, which multiplies antennas to reach 600 Mbit/s. IEEE 802.11ac crossed the symbolic gigabit-per-second threshold in 2013, with a theoretical throughput of 3.5 Gbit/s.
This performance race responds to growing connectivity needs. Early Wi-Fi networks struggled to load a simple web page, while today we stream 4K movies on multiple devices simultaneously. IEEE 802.11ax, branded as Wi-Fi 6 and published in 2021, pushes throughput to 9.6 Gbit/s while better managing dense environments like stadiums or airports. The standard incorporates sophisticated spectrum-sharing mechanisms and reduces device power consumption.
Wi-Fi has changed far more than just how we connect to the internet. The technology has redesigned workspaces, enabling professional nomadism. Coffee shops have become makeshift offices, airports have turned into meeting rooms. In our homes, Wi-Fi has enabled the explosion of connected devices, from thermostats to light bulbs to speakers. Schools and universities have rethought their teaching methods around this permanent connectivity.
Radio communications security was long an Achilles’ heel, with early protections like WEP quickly becoming obsolete. WPA3 encryption now offers a satisfactory level of protection. Interference between devices, coexistence with other wireless technologies like Bluetooth, limited signal range: all problems that have found technical solutions over successive versions.
The future looks more ambitious. Wi-Fi 7 (IEEE 802.11be), finalized in 2024, targets 40 Gbit/s in theoretical throughput. These performance levels open prospects for virtual or augmented reality, which require minimal latency and considerable throughput. The integration of artificial intelligence in network management should improve dynamic spectrum allocation and user experience.
From the ALOHAnet experiment to Wi-Fi 6 networks, the journey illustrates computing’s ability to transform a laboratory idea into everyday technology. Wi-Fi has become invisible precisely because it is omnipresent, present in our pockets, our homes, our cars. This discreteness paradoxically testifies to its success: the best technologies are those we no longer notice.