In 2010, Clearwire, the largest 4G service provider in the United States, announced that it has begun trials in Chicago of its first high-efficiency “green” base station cabinets. This new generation of base station cabinets is capable of achieving up to 90 percent reduction in electrical operating expenses and would not require the use of HVAC equipment in the majority of the company’s nationwide deployment. Following completion of the trials, the new base station designs are expected to be introduced throughout the Clearwire network.