Unlocked GSM Cell Phone

Recent years have seen an increase in the number of GSM network providers, users and cellular phones in the US. Previously, CDMA was the most popular network in the United States. CDMA technology has existed for much longer, having been developed by British allies for the secure encryption of messages in World War II. When GSM phones became available, with their then-unique brand of text messaging, GSM became a major hit in the States, especially among teenagers. GSM phones are important today because, due to their use of SIM card technology, they can be purchased as unlocked cellular phones or otherwise made into unlocked phones.