Japanese cellular carrier will provide $24 million to help AT&T build phone network and promote roaming in the U.S. NTT DoCoMo will partially fund the construction of AT&T’s 3G phone network in Hawaii, it said Thursday.The unusual agreement will see NTT DoCoMo, Japan’s largest cellular carrier, provide AT&T with $24 million to help it build the network. The network will be based on WCDMA (Wideband Code Division Multiple Access) and AT&T will launch service on the island of Oahu late this year and statewide in 2008, NTT DoCoMo said in a statement.Hawaii is a major holiday destination for Japanese tourists but most NTT DoCoMo customers can’t use their cellphones on the island. That’s because the carrier’s 2G handsets are based on a proprietary standard used only in Japan and because in most 3G phones it has left out GSM (Global System for Mobile Communications) compatibility leaving only 3G for overseas roaming. Because the proprietary 2G format kept many previous handsets offline many consumers aren’t used to it and don’t look for it when buying a new handset. Although that’s slowly changing as more experience the convenience of using their phone overseas for the first time.NTT DoCoMo said it will work with AT&T to promote roaming in the U.S. as a result of the deal.Last year NTT DoCoMo made another investment in the Pacific when it acquired Guam Cellular & Paging and then used that company to acquire Guam Wireless Telephone Company. The investments, which totaled about $72 million, were made to speed up the introduction of WCDMA on Guam and help its roaming business. Guam is another major tourist destination for Japanese people. Technology IndustrySmall and Medium Business