Patent walls were (are?) a patent feature of many BigCorps. I've seen at least three, and none of them were QualComm.

There are certainly others. Micron has a patent wall. For a period of time under CEO Steve Appleton, meetings with engineers were prohibited [Fridays or half of Friday?] because the engineers should be working on parents during that time.

My understanding is their strong patent portfolio was a good part of why they are still around after the massive consolidation of DRAM manufacturers through the 80's and 90's.

IBM has done this as well.

It's pretty common – I've seen a wall o' patents in at least two (non-Qualcomm) offices!

Got one, and we are much smaller than qcom.

McData did that when they existed.