I was on a bus in Barcelona last week with a colleague I had not seen in years. As we chatted, I got a phone notification of a tweet of hers. We were both rather shocked. It could be coincidence, but it seemed likely that Twitter had tracked that we were close by and travelling the same route.

We happened to be on our way to the announcement of a 5G smartphone by China’s Xiaomi . With hundreds of seemingly genuine Xiaomi fans — who knew there was such a thing? — whooping and clapping as if it was an Apple event.

The promise of 5G, for which Qualcomm makes chips, is of faster, more pervasive networks to more reliably perform such tricks as noticing you are on the same bus as someone you know. The Mobile World Congress, of which the Xiaomi event was part, was largely a celebration of 5G, which will start to go live this year.