Multichannel queuing systems with balking and regenerative input fl ow

Motivated by the application to telephone call centers this paper is focused on the multichannel queueing system with heterogeneous servers, regenerative input ow and balking. Servers times are random variables but not necessary exponential. If a new customer encountering j other customers in the system then it stays for service with probability fj and gets rejection with probability 1 ?? fj . For such a system an ergodicity condition is established and functional heavy trac limit theorems are proved under critically loaded ( " 1) and overloaded conditions ( 1)