I'm looking at this from the point of view of the technology, rather than the standards, as that's where I was involved. From a technology point of view, 802.11b (particularly its 1 and 2Mbps modes) was developed before 802.11a, and so is "older". I know this, because I had the design for the world's first 802.11a modem on my computer's screen, and one of the professors had earlier bought an instance of a DSSS WLAN (essentially 802.11b) to see how it performed.
Granted the early "802.11b" radios might not have been CMOS. Their frequency was limited by what was technically possible in a consumer product though. I can't remember exactly what was in that "802.11b" WLAN. The 802.11a band was definitely set by what was possible in CMOS. The CMOS radio itself might not have existed in 1995, but planning was in progress and we had a pretty good idea of what was possible.
802.11b was CCK modulation (and to a lessor extent PBCC, but that didn't take-off).
DSSS wasn't 802.11b, it was 802.11 (or half of it, the other PHY at that point was FHSS). 802.11b's 1Mbps and 2Mbps modes were DSSS, and pre-existed 802.11b. These (and the FHSS PHY) were all part of the 1997 standard. 802.11b and 802.11a came along in September of 1999.
Who is 'we'? Because you don't seem to know what you're talking about.
I'm one of the other authors. Maybe I'm wrong, in that the written history tells it differently, but I'm recalling what was said around the meeting table and across the office partition. I might be a bit loose with the terminology, but to me it's not packaged up neatly into standards, as it was a non-linear development process when I was dealing with it.
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Edit: fix URL + name
after a little googling i can find references to papers pblished in 1994 and 1995 that refer to GHz CMOS components (eg A. Rofougaran et al., A 1 GHz CMOS RF
Front-end IC with Wide Dynamic Range,
ESSCIR, 1995, pp. 250-253; J. Carols and M. S. J. Steyaert, A 1.5 GHz Highly
Linear CMOS Down Conversion Mixer, IEEE
Journal of Solid-State Circuits, Vol. 30, 1995,
pp. 736-742.)
i know nothing about this, so perhaps they are irrelevant, but on face value it seems like a 2.5GHz system could have existed in labs at that date, or at least was clearly going to be possible.
Granted the early "802.11b" radios might not have been CMOS. Their frequency was limited by what was technically possible in a consumer product though. I can't remember exactly what was in that "802.11b" WLAN. The 802.11a band was definitely set by what was possible in CMOS. The CMOS radio itself might not have existed in 1995, but planning was in progress and we had a pretty good idea of what was possible.