NanaGsm Wireless is the most affordable growing Cell Phone Repair & Unlocking Centers in the Washington DC Metropolitan Area. We specialize in all types of iPhones such as iPhone 7, 6S, 6, 5S, iPod, iPad. We encourage customers to stop by and see why our clients keep coming back, to quality service. Our Lead Technician has over 5 years of mobile phone repair experience. Our main focus is to provide high quality, convenient, and cost effective repairs to our customers. Thanks for visiting us.- What is GSM ? GSM-(Global System for Mobile communications) is an open, digital cellular technology used for transmitting mobile voice and data services. What does GSM offer? GSM supports voice calls and data transfer speeds of up to 9.6 kbit/s, together with the transmission of SMS (Short Message Service). GSM operates in the 900MHz and 1.8GHz bands in Europe and the 1.9GHz and 850MHz bands in the US. The 850MHz band is also used for GSM and 3G in Australia, Canada and many South American countries. By having harmonised spectrum across most of the globe, GSM’s international roaming capability allows users to access the same services when travelling abroad as at home. This gives consumers seamless and same number connectivity in more than 218 countries. Terrestrial GSM networks now cover more than 80% of the world’s population. GSM satellite roaming has also extended service access to areas where terrestrial coverage is not available.