— This paper presents a novel stochastic link-layer channel model for IEEE 802.11 ad hoc networks. The model characterizes the variations of the channel service process in a non-saturated case using a Markov-modulated Poisson process (MMPP) model. It offers a tool for distributed statistical resource allocation in ad hoc networks, which combines efficient resource utilization and quality-of-service (QoS) provisioning to a certain probabilistic limit. We also propose a distributed call admission control algorithm based on the link-layer model. Simulation results demonstrate that the model can be used efficiently in allocating resources with stochastic QoS guarantees. Keywords – IEEE 802.11 MAC, ad hoc network, queuing model, resource allocation, call admission control