The document proposes a novel approach for mobile users to collect network-wide data from wireless sensor networks. The routing structure for data collection is additively updated as the mobile user moves through the network. This approach only requires limited modifications to update the routing structure, while maintaining routing performance bounded and controlled compared to optimal performance. Analysis shows the approach is scalable with low maintenance overheads, efficient routing performance, and provides continuous data delivery during user movement. The protocol was implemented in a 49-node testbed and simulations examined its efficiency and scalability under varied network settings.