channel goes idle. The concept of a RLP protocol was invented by Phil Karn in 1990 for CDMA (IS-95) networks. The January 2006 IEEE 802.20 specification uses one of the newest forms of RLP. Cellular networks such as GSM and CDMA use different variations of RLP. In UMTS and in LTE, the protocol is called RLC (Radio Link Control). Wireless networking Radio resource management Link protocols