http://www.gsmarena.com/samsung_galaxy_s2_specs_and_photo_leak_before_mwc_starts-news-2318.php
The wifi support is for 802.11a/b/g/n, with 802.11a working on 5Ghz frequency rather than the more conventional 2.4 band, so it might be a dual band wifi support. Mobile data will apparently be HSPA+