Single server retrial queues with priority calls

We present a survey of retrial queues with two types of calls and present new results of several models. We consider the M1,M2/G/1 retrial queue and its variations which are the model with different service times, the model with geometric loss, the model with feedback, the model with batch arrivals and vacations, the model with recurrent calls in the retrial group, the model with retrial rate control policy, the model with threshold in the retrial group and the model in the discrete system.