The wireless industry may be getting through the recession relatively unscathed compared to other sectors, but mobile operators still face tough challenges. As in the handset segment, where resilience has been seen at opposite ends of the spectrum – smartphones and emerging market handsets – the strongest areas for cellcos have been mobile data services and low cost prepaid propositions. But globally, 40% of mobile operators experienced a dip in service revenues in the difficult first quarter of this year, up from 16% in the year-ago quarter. According to Strategy Analytics’ latest report, total service revenues were $163 billion, while the number of subscribers was up 17% year-on-year to 3.67 billion, though nearly all this growth in Q109 came from…