The coordinated coexistence of WLANs and WPANs in a dual-mode network is a recently introduced idea and is expected to increase the overall system performance by allowing for the efficient cooperation of both WLANs and WPANs. Topology control (e.g., power control, smart antennas, and different frequency channels) needs to be employed to allow for the simultaneous operation of both modes. In this paper, different frequency channels that allow for high data rates within a small transmission range are considered in order to create multiple WPAN environments inside a WLAN cell. The latter environment requires the support of a second mode of operation which introduces additional overhead that may degrade the overall system performance. Certain conditions, under which system performance improvement is achievable, are established here. In particular, an analytical mobility model for WPAN environments is proposed and employed in the analytical studies. It is shown that the system may be effective when node mobility is low and the traffic load among nodes is high. The corresponding upper and lower bounds on mobility and traffic are also analytically derived. Simulation results for a variety of scenarios support the claims and expectations of the aforementioned analysis and demonstrate that performance improvement is possible when WLANs and WPANs coexist and cooperate in a network. 2006 Elsevier B.V. All rights reserved.