The photograph “Signal” was taken along the shores of the Red Sea on an evening of a full moon in Djibouti City, Djibouti. I was there on assignment photographing the story “Out of Eden”, a project with National Geographic explorer Paul Salopek related to our collective human migration out of Africa that began some 60,000 years ago.

After a month traveling overland from a small village in Ethiopia, I arrived in Djibouti City. On my second day in the capital, I did what I often do when in a place I’ve never been before — walk about in the natural process of getting lost. While meandering along the beach, I came upon a group of people at dusk, all standing at different spots along the shoreline holding up their phones, some talking on them, others waving them in the air or just standing motionless.

I asked my friend/translator what they were doing as it was truly one of the more unique gatherings I’d ever stumbled upon. He said there are people, mostly Somalis, who often come to this spot along the beach to try and do what is called “Catching”—to catch an inexpensive signal from neighboring Somalia by using a Somali SIM card in their phones.