Bluetooth: From Kings to Personal Area Networks

Bluetooth The King Ragnar Lodbrok was a legendary Norse king, conquering parts of Denmark and Sweden. And if we’re to believe the songs, he led some of the best raids against the Franks and the the loose patchwork of nations Charlemagne put together called the Holy Roman Empire. 

We use the term legendary as the stories of Ragnar were passed down orally and don’t necessarily reconcile with other written events. In other words, it’s likely that the man in the songs sung by the bards of old are likely in fact a composite of deeds from many a different hero of the norse.   Ragnar supposedly died in a pit of snakes at the hands of the Northumbrian king and his six sons formed a Great Heathen Army to avenge their father. His sons ravaged modern England int he wake of their fathers death before becoming leaders of various lands they either inherited or conquered. One of those sons, Sigurd Snake-in-the-Eye, returned home to rule his lands and had children, including Harthacnut. He in turn had a son named Gorm. 

Gorm the Old was a Danish king who lived to be nearly 60 in a time when life expectancy for most was about half that. Gorm raised a Jelling stone in honor of his wife Thyra. As did his son, in the honor of his wife. That stone is carved with runes that say:

“King Haraldr ordered this monument made in memory of Gormr, his father, and in memory of Thyrvé, his mother; that Haraldr who won for himself all of Denmark and Norway and made the Danes Christian.”

That stone was erected by a Danish king named Herald Gormsson. He converted to Christianity as part of a treaty with the Holy Roman Emperor of the day. He united the tribes of Denmark into a kingdom. One that would go on to expand the reach and reign of the line. Just as Bluetooth would unite devices. Even the logo is a combination of runes that make up his initials HB. Once united, their descendants would go on to rule Denmark, Norway, and England. For a time. Just as Bluetooth would go on to be an important wireless protocol. For a time. 

Personal Area Networks Many early devices shipped with infrared so people could use a mouse or keyboard. But those never seemed to work so great. And computers with a mouse and keyboard and drawing pad and camera and Zip drive and everything else meant that not only did devices have to be connected to sync but they also had to pull a lot of power and create an even bigger mess on our desks. 

What the world needed instead was an inexpensive chip that could communicate wirelessly and not pull a massive amount of power since some would be in constant communication. And if we needed a power cord then might as well just use USB or those RS-232 interfaces (serial ports) that were initially developed in 1960 - that were slow and cumbersome. And we could call this a Personal Area Network, or PAN. 

The Palm Pilot was popular, but docking and pluging in that serial port was not exactly optimal. Yet every ATX motherboard had a port or two. So a Bluetooth Special Interest Group was formed to conceive and manage the standard in 1988 and while initially had half a dozen companies now has over 30,000. The initial development started in the late 1990s with Ericcson. It would use short-range UHF radio waves in the 2.402 GHz and 2.48 GHz bands to exchange data with computers and cell phones, which were evolving into mobile devices at the time.

The technology was initially showcased at COMDEX in 1999. Within a couple of years there were phones that could sync, kits for cars, headsets, and chips that could be put into devices - or cards or USB adapters, to get a device to sync 721 Kbps. We could add 2 to 8 Bluetooth secondary devices that paired to our primary. They then frequency hopped using their Bluetooth device address provided by the primary, which sends a radio signal to secondaries with a range of addresses to use. The secondaries then respond with the frequen