Delegates arrived at the Mobile World Congress in Barcelona on Monday (June 28).
But the technological trade show kicked off under strict measures.
After having to cancel in 2020, the fair faces the challenge of attracting exhibitors.
The annual telecoms industry gathering is normally a star event for mobile brands to unveil new offerings.
But a number of big companies have either dropped out entirely or opted for virtual activities.
Big names including Huawei, Lenovo and Vodafone are showing up.
But Ericsson, Nokia and Samsung are staying away.
In order to prevent touching badges, people attending the fair have to use a QR code or a biometric face recognition system to identify themselves at the entrance.
In contrast with the crowds packing the entrance in previous editions, this year small groups were seen queuing early in the morning.
The Mobile, as the event is also known, is the first big technology conference staged in Europe since the pandemic began.
Organisers hope the number of attendees will range between 30,000 to 40,000.
Down from 100,000 in 2019.