Multi-RAT scheduling for heterogeneous networks

Mobile network operators are required to support a number of users utilizing various Radio Access Technologies (RATs). While operating in a costly, licensed spectrum, the efficiency of its utilization is of crucial importance. This will promote newer RATs, supporting higher spectral efficiency. On the other hand, the quality of service for older RATs' users has to be maintained. This paper proposes a scheduling algorithm, dynamically distributing time-frequency resources between two or more RATs. Interference between RATs is modeled and considered while allocating resources. The algorithm is presented and validated by means of simulations for a coexistence of GSM and LTE systems. This solution is proved to be spectrally efficient in dynamic resource distribution, especially for traffic demand varying in time among different RATs.