This is an early situation review when the quake struck. Time is all expressed in Japan Standard Time. 3/11(Fri) 2:46pm The first quake occured off the coast of Miyagi prefecture, Northern Japan (Tohoku area). The second big one occured about 30 minutes later off the coast of Ibaragi prefecture (Kanto area).
Unknown number of cell sites were destroyed and mobile traffic was quite congested right after the quake. At Narita Airport near Tokyo, I tried to call my parents in Kanagawa prefecture with my Japanese cell phone and did not go through. I could send out mobile e-mails, but did not get any reply for a few hours.
After 2 hours or so, I started to see many people on cell phone outside of Narita, where everyone in the airport building evacuated. So I tried to call again and got through. After another 1/2 hour, my sister called me to my cell.
According to them, mobile e-mails were taking about 2 hours to be delivered. Family members were exchanging mobile e-mails asking "are you OK?" to each other, and the other side got them after everyone came home.
Still I could not receive any mobile e-mails at all.
I was lucky to be in the Airport, where WiFi was restored in a few hours. I noticed that my Verizon Android phone (I did not use 3G roaming) have WiFi connection at around 7pm. E-mails were still slow but Twitter was working fine, so I started tweeting that I was OK. Twitter, Facebook, SMS via GoogleVoice started to puring in. Airport WiFi was totally fine, it kept working all night.