1985: the spectrum opens. The US regulator (FCC) allowed unlicensed use of the 900 MHz, 2.4 GHz and 5.8 GHz bands for spread-spectrum radios. Without this decision there would be no Wi-Fi. Late 1980s: the first wireless LANs. NCR, later part of AT&T, developed WaveLAN in the Netherlands. Vic Hayes from that team went on to chair the IEEE 802.11 working group for a decade and is often called the father of Wi-Fi. Early 1990s: solving the echo problem. In Australia, a CSIRO team led by John O'Sullivan, with Terry Percival, Graham Daniels, Diet Ostry and John Deane, tackled the biggest obstacle indoors: radio signals bouncing off walls and arriving as smeared echoes. Their patented approach, building on OFDM and error correction, became important to later Wi-Fi standards, and CSIRO went on to earn hundreds of millions of dollars in licensing settlements. 1997: the first standard. IEEE 802.11 was published, offering 1 and 2 Mbps in the 2.4 GHz band. 1999: Wi-Fi gets a name. 802.11b raised speeds to 11 Mbps at 2.4 GHz, and 802.11a introduced OFDM at 54 Mbps in 5 GHz. The industry group that became the Wi-Fi Alliance formed the same year, and the name "Wi-Fi" was born. 2003 to 2013: faster and smarter. 802.11g brought 54 Mbps to 2.4 GHz. 802.11n (now called Wi-Fi 4) added MIMO, sending several data streams at once. 802.11ac (Wi-Fi 5) moved to wider 5 GHz channels and added multi-user MIMO. 2019 onward: efficiency and new spectrum. Wi-Fi 6 introduced OFDMA to serve many devices at once, and Wi-Fi 6E opened the 6 GHz band. Wi-Fi 7, certified from 2024, adds 320 MHz channels, 4096-QAM and multi-link operation across bands at the same time. Each generation solved a real problem: interference, echoes, crowded spectrum, too many devices. Understanding those problems is still the best way to troubleshoot Wi-Fi today.