AT&T said it invested $11 million in capital improvements in Hawaii during the first six months of this year, the bulk of which was for its wireless network.

Additions included adding three new cellular sites, two on Oahu and one on Maui, AT&T said in a news release. Three additional sites were upgraded to accommodate mobile broadband service, and the company’s wireline network was improved to include additional Wi-Fi hot spots and extended reach of broadband services.

Nationwide, AT&T said plans to invest $18 to $19 billion in capital improvements this year, about 10 percent more than in 2009.