Flow-level Performance Analysis Of D2D Communication In Mobile Cellular Network

With the development of mobile network, more and more proximity-based services emerge, which makes the D2D technology popular. This paper studies the flow-level performance in terms of mean delay and mean throughput in D2D overlaid and underlaid cellular network, based which the system parameter is analyzed to obtain the optimal system performance.Spectrum partition and mode selection are two fundamental issues in D2D overlaid cellular networks, whose performance has been studied at the packet level for a static user population assuming infinite backlogs. In this paper, we focus on the flow-level performance in a scenario with user dynamics governed by the arrival and completion of random service demands over time. We show that in certain cases the flow-level performance can be evaluated by means of a queuing model with a dispatcher that assigns the service demands to two independent Processor Sharing servers. The model provides closed-form expressions for the mean number of users, the mean delay and the mean throughput, based on which the optimal spectrum partition and mode selection parameters can be derived and useful insights for the design principle can be obtained. Finally we perform numerical experiments to validate our model.In this paper, we study the flow-level performance of an Orthogonal Frequency Division Multiple (OFDM)-based cellular network with underlay D2D,where the uplink cellular spectrum is shared by the cellular and D2D users. In specific, we formulate a coupled processor queuing system with two types of queues to model the flow-level system behavior, where the service rates are derived based on the stochastic point processes of user positions. Since the state space of the queuing model grows exponentially with the number of D2D users and cells, we use the model decomposition and iteration technique to derive its approximate steady-state solution, so that we can obtain the flow-level performance in terms of mean delay and energy consumption. Simulations are performed to verify the analytical results under different traffic loads. The proposed flow-level performance model has practical implications for the network deployment and parameter tuning with regard to D2D communications.