关键词：GSM网络；移动电话服务；农村
摘 要：we argue that GSM whitespaces should be regulated for dynamic spectrum sharing, and that doing so will support the growth of community cellular networks and thereby improve rural access to communications services. We propose a hybrid sensing and database-driven spectrum sharing scheme called Nomadic GSM that provides safe coexistence between primary and secondary users without requiring coordination or cooperation from existing license holders.