I think you might be referring to the patents from Nokia. These are licensed on FRAND terms. Nokia was one of the original inventors of GSM and owns a considerable patent portfolio especially on the network tech.
I don't think MS ever owned the Nokia communication patents. They only took over the phone and devices business. Nokia the telecom and information technology company still lives and bought (merged with) Alcatel who had previously bought Lucent.
Bell labs (who is doing a lot of telecom R&D) for example is owned by Nokia now (it's called Nokia Bell labs)
