Would anyone at the time know what they were doing? Was there ever a similar protocol in existence yet? If the answer is yes, why did we need BT to be created?
20 years ago I was working on firmware for cheap narrow band spread spectrum cordless phone IC's.
It's easy to see the mistakes they made. If you look at the early to mid 1990's, there were cheap FM radio IC's that drew a couple of ma. At the same time ISM band microwave IC's were expensive, made of GaAs and just an LNA would cost you 50-100ma.
Wifi did exist back then. But the cost was around $150-200 for a chip set and the power requirements precluded battery operation.
So 'of course' they went with a low power FM radio.
The problem was as you shrink CMOS transistor sizes they get faster. By the late 1990's you could build a direct sequence transceiver IC out of CMOS. The one my group rolled out in 1999 drew about 200mA in receive mode and cost $4/1M
Zigbee came two three years later and the power requirements were down to 25-50mA.
Bluetooth designers completely failed to judge the progress being made in CMOS RF IC design. That was completely obvious to anyone in the industry.
The second problem had to do with the baseband. The Bluetooth baseband has several layers and essentially replicates the USB protocol/driver stack. Notice how easy it was for Microsoft to roll out the USB stack? Yeah total shitshow.
So you had a dumb simple frequency hopping radio married to a complicated baseband.
The rub, out of about two dozen companies that tried to build Bluetooth radios' circa 2000, all but three failed. Because they couldn't get the base band power consumption low enough.
Usually when you design a spec like Bluetooth you get your potential manufacturers on board working on silicon as you design the spec. They didn't.
Notable the Zigbee spec had the same problem with it's baseband and most people solved that problem by ignoring it and just using the radio.
A third problem (which effected Zigbee as well) is the transmit power was too low. Made worse with Bluetooth because the FM radio's sensitivity sucks. Back then I knew from cordless phone stuff that you needed at least 5db of transmit power to get reliable QOS. Bluetooth and first gen Zigbee radio's had less than 0db.
All of the above a small brained primate like myself could have told you.
Comments
Would anyone at the time know what they were doing? Was there ever a similar protocol in existence yet? If the answer is yes, why did we need BT to be created?
20 years ago I was working on firmware for cheap narrow band spread spectrum cordless phone IC's.
It's easy to see the mistakes they made. If you look at the early to mid 1990's, there were cheap FM radio IC's that drew a couple of ma. At the same time ISM band microwave IC's were expensive, made of GaAs and just an LNA would cost you 50-100ma.
Wifi did exist back then. But the cost was around $150-200 for a chip set and the power requirements precluded battery operation.
So 'of course' they went with a low power FM radio.
The problem was as you shrink CMOS transistor sizes they get faster. By the late 1990's you could build a direct sequence transceiver IC out of CMOS. The one my group rolled out in 1999 drew about 200mA in receive mode and cost $4/1M
Zigbee came two three years later and the power requirements were down to 25-50mA.
Bluetooth designers completely failed to judge the progress being made in CMOS RF IC design. That was completely obvious to anyone in the industry.
The second problem had to do with the baseband. The Bluetooth baseband has several layers and essentially replicates the USB protocol/driver stack. Notice how easy it was for Microsoft to roll out the USB stack? Yeah total shitshow.
So you had a dumb simple frequency hopping radio married to a complicated baseband.
The rub, out of about two dozen companies that tried to build Bluetooth radios' circa 2000, all but three failed. Because they couldn't get the base band power consumption low enough.
Usually when you design a spec like Bluetooth you get your potential manufacturers on board working on silicon as you design the spec. They didn't.
Notable the Zigbee spec had the same problem with it's baseband and most people solved that problem by ignoring it and just using the radio.
A third problem (which effected Zigbee as well) is the transmit power was too low. Made worse with Bluetooth because the FM radio's sensitivity sucks. Back then I knew from cordless phone stuff that you needed at least 5db of transmit power to get reliable QOS. Bluetooth and first gen Zigbee radio's had less than 0db.
All of the above a small brained primate like myself could have told you.
It's worse then you think because Bluetooth is a frequency hopper which means Streaming QOS is limited by the link margin on your worst channel.