Archive
All twenty guides
The complete roster, by section. Twenty pieces across five sections.
Lineage · Two lines of descent
- Two megabits, and almost nobody used itThe original 802.11 was ratified in 1997 at up to 2 Mbit/s, and it took 802.11b in 1999 to make wireless networking practical.
- a, g, n, ac, ax — a line that became unreadableThe lettered amendments carried real technical changes, and by 2018 the Wi-Fi Alliance renamed them retroactively because the letters had stopped communicating.
- Adding a band, then adding widthWi-Fi 6E opened the 6 GHz band and Wi-Fi 7 widened channels and added multi-link operation, both of which are spectrum decisions before they are silicon ones.
- A parallel line, defined by releasesGSM from 1991 through UMTS to LTE in 2009 is a sequence of 3GPP releases, which is why cellular generations have dates rather than launch events.
- Two very different things under one name5G NR splits into sub-6 GHz and mmWave, and the difference in reach between them is large enough that they behave like separate technologies.
Spectrum · The part nobody sees
- The unlicensed slice everything crowds intoThe ISM bands were set aside for industrial, scientific and medical use, and Wi-Fi, Bluetooth and Zigbee all share them by accident of that allocation.
- The same band is not the same bandThe ITU divides the world into three regions with different allocations, which is why the same handset supports different bands in different markets.
- Governments sell the airNational spectrum auctions have raised sums comparable to infrastructure budgets, and the price paid shows up in what carriers build.
- A band two industries both wantedOpening 6 GHz for unlicensed use was contested by incumbent licensees, and different regulators resolved it differently.
Committee · Who actually decides
- A working group, not a companyIEEE 802.11 is a working group whose output is a document, and the ballot process explains why amendments arrive in the order they do.
- Releases as a clock3GPP numbers releases rather than years, and a feature's real availability date is the release it landed in plus the silicon lag.
- Certification is a separate businessThe Wi-Fi Alliance and Bluetooth SIG certify and name; they do not write the underlying standard, which is a distinction that gets lost constantly.
Hardware · What has to implement it
- Everything between the antenna and the chipFilters, amplifiers and switches in the RF front end determine real performance more often than the baseband does, and they are band-specific.
- More antennas, more pathsMIMO and MU-MIMO use multipath as a resource rather than a problem, and the antenna count in a device is a direct consequence.
- Radios designed to sleepBLE, Zigbee, Thread and LoRaWAN trade throughput for duty cycle, and each picked a different point on that curve for a stated reason.
- Power arriving through the antennaNFC and passive RFID draw their power from the reader's field, which is why range is measured in centimetres and why the tag can be a sticker.
Timeline · In order, with dates
- GSM goes liveThe first GSM networks opened in 1991 and set the pattern of a standard defined before deployment rather than after it.
- LTE, and the end of the circuitLTE moved cellular to an all-IP core, which is the change that made voice a service on the data network rather than the other way round.
- Wi-Fi 6 was a rename, not a releaseThe Wi-Fi Alliance applied generation numbers retroactively in 2018, an admission that the lettering had failed as communication.
- Wi-Fi 7 and the width problemWi-Fi 7's widest channels need spectrum that not every regulator has released, so the same product performs differently by country.