GSM was allowed in the United States, but the radio frequencies were blocked and awarded to US "Carriers" to use US technology, which limited development of mobile messaging services in the US. The GSM in the US had to use a frequency allocated for private communication services (PCS) – what the ITU frequency régime had blocked for DECT (Digital Enhanced Cordless Telecommunications) – a 1,000-foot range picocell, but it survived.