Count. According to the news released by China Unicom in official website, 156 is defined as China Unicom's 2G segment, which is an old segment, while the new segment 186 is the first batch segment added by China Unicom on June 5438+1October 07, 2009 for 3G networks in 336 cities across China. Unicom focuses on the information needs of digital government, medical and health care, industrial manufacturing, online education, eco-environmental protection, transportation, cultural tourism and other industries.