Abstract —In this paper, we focus on the radio resource management (RRM) in heterogeneous networks with orthogonal frequency division multiple access (OFDMA), and aim to maximize the system sum-rate and meet quality of service (QoS) requirements under the proportional fairness constraint of user rates. The previously proposed resource allocation schemes, which do not differentiate the traffic types or consider the fairness performance, may result in inefficient allocation of radio resources. To tackle this problem, we present an analytical model which takes consideration of two types of the traffic including the Delay-Constraint (DC) traffic and the Best-Effort (BE) traffic, and then formulate the RRM problem as a linear programming (LP) problem. We propose an efficient iterative algorithm to find the optimal solutions by converting this combinatorial problem with exponential complexity into a convex problem or showing that it can be solved in the dual domain. Numerical studies are conducted to evaluate the performance of the proposed algorithm in terms of achievable transmission rate for the DC traffic and fairness for the BE traffic, multiuser diversity, and system throughout.