Q: Passage: In 1979, the merger of Nokia and Salora resulted in the establishment of "Mobira Oy". Mobira developed mobile phones for the Nordic Mobile Telephone (NMT) network, called the "1G" and was the first fully automatic cellular phone system. It became commercially available in 1981. In 1982, Mobira introduced its first car phone, the "Mobira Senator" for NMT -- 450 networks.

Question: Based on this passage, when was the first nokia mobile phone invented?
Let's give stream of consciousness below
This is the relevant information: It became commercially available in 1981. So the answer is 1981.