US Patent 9008671 Integrated multi-radio access technology multi-frequency admission control

A node of a multiple radio access technology (multi-RAT) system acquires resource status information associated with each RAT of the multi-RAT system. The resource status information of the RATs of the multi-RAT system can be acquired by sniffing higher layer protocol information pertaining to call setup requests and/or call terminated messages. The node further maintains a flag representing overall resource availability associated with the RATs of the multi-RAT system, based on the acquired resource status information, for use in admission control and/or load balancing. The flag is associated with a pre-defined set of overall resource availability states of the multi-RAT system, where the availability states are defined in terms of admission control decisions.