Capacity of a Cellular Network with D2D Links

Cellular controlled direct UE to UE (User Equipment) communications represent a rich area for research and development that includes topics such as public safety, new social applications, as well as enhancing cellular coverage and capacity. Much of the work is motivated by the growth in wireless data demand, and the expected explosion of new uses of cellular technology. Our study extends the traditional cellular topology to enable direct path links (DPLs) between UEs for local discovery and communication, referred to as device-to-device communication. Local traffic offloading can be used for social networking, wireless gaming, machine type communication, as well as for public safety. We present system throughput results using Monte Carlo simulation techniques for a system which enables the DPLs. Our results indicate that the mean system capacity could be improved by more than 200% by using direct path UE communications as an enhancement to traditional cellular systems, such as LTE.