Some real-time applications (such as Video On Demand) are sensitive to the perceived packet loss when using the network resources. Due to time-varying topological changes in a wireless ad hoc network, it is a challenging issue to provide this stringent QoS requirement of real-time applications. Each real-time application requires a specific level of packet loss guarantee. As multi-path routing has the potential of reducing the congestion and increasing the throughput of the user traffic in multi-hop wireless networks, it is assumed that multiple paths are available in advance between each source-destination pair. In the current work, using a constrained optimization framework and trying to minimize the packet loss, an optimal rate is allocated to each source-destination path of those subsets of real-time applications which requires minimized packet loss and a lower bound on the delivered bandwidth. Simulation results verify the enhanced performance of the proposed method in terms of the packet error rate.