Sunnyvale-based Ruckus Wireless, which provides carrier-class WiFi equipment for communications carriers, slipped slightly in its IPO Friday morning. The firm priced at $15 per share, selling 8.4 million shares of its stock last night. The firm priced above its initial IPO range of $13.00 to $15.00 per share. Ruckus started trading on the NYSE as RKUS this morning. The firm was down as low as $13.75 in rough markets Friday morning. The firm was venture backed by Sequoia Capital, Motorola Mobility, and others.