Date Added: Sep 2011
The technological foundation of Fourth Generation (4G) cellular systems was outlined in the Long Term Evolution Advanced (LTE-A) standards which enable communication rates of 100 Megabits per second for mobile communications and 1 Gigabit per second for nomadic ones. In LTE-A the deployment of wireless intermediate communication-assisting nodes, known as relays, was standardized for the first time. Under ideal conditions it has been envisioned that the deployment of relays will enhance the network coverage and will enable reliable communication at the cell periphery. Despite the envisioned gains of LTE-A based systems, practical field tests indicate that slight deviations from the ideal conditions can result in significant loss in achievable rates and service coverage.