A great success of Wireless Sensor Networks (WSNs). Recent advances in Wireless Sensor Network technologies provide people the ability to better understand the physical world. With the data collected from the entire network, the sensor network supports a variety of applications, including security surveillance, localization, information enquiry, and transmission. The ubiquitous data collection by mobile users in the wireless sensor network. Mobile users are equipped with handheld devices that communicate with sensor nodes and instantly access the network through nearby sensors. A pervasive usage of sensor networks explores in-situ interactions with human beings, provides people facilitated means of data collection, and thus significantly expands the capability of wireless sensor networks. Scientific data of the forest, such as temperature, humidity, concentration of carbon dioxide and so on. On the other hand, there are a number of forest rangers patrolling around the mountain to detect any accidents in the forest, like the fire indication, the vegetation damage, etc. Equipping the rangers with communicational devices and enabling them collect the field data of interest from the sensor network anywhere and anytime would largely benefit their work. The routing transitions between
different data collection trees contain a non negligible time delay and may lead to discontinuity or even loss of the data delivered to the mobile user, which significantly decreases the QoS of ubiquitous data collection. The ubiquitous data collection problem studied in this paper is essentially different from conventional mobile sink-based data collection. The sink mobility has been introduced to benefit the data collection operation, e.g., to improve the network lifetime. The mobile sink is essentially cooperative to the data collection. The design details of three components in our protocol: 1) Data Collection Tree Initialization, 2) Data Collection Tree Updating, and 3) Data Routing. The mobile user keeps moving around and the virtual sink that connects the user to the sensor network changes accordingly