Dynamic Proxy Tree-Based Data Dissemination: A dynamic proxy tree-based data
dissemination framework [48] was proposed for maintaining a tree connecting a source sensor to
multiple sinks that are interested in the source. This helps the source disseminate its data directly
to those mobile sinks. In this framework, a network is composed of stationary sensors and several
mobile hosts, called sinks. The sensors are used to detect and continuously monitor some mobile
targets, while the mobile sinks are used to collect data from specific sensors, called sources,
which may detect the target and periodically generate detected data or aggregate detected data
from a subset of sensors. Because of target mobility, a source may change and a new sensor
closer to the target may become a source. Each source is represented by a stationary source proxy
and each sink is represented by a stationary sink proxy. The source and sink proxies are
temporary in the sense that they change as the source sensors change and the sinks move. A
source will have a new source proxy only when the distance between the source and its current
proxy exceeds a certain threshold. Likewise, a sink will have a new sink proxy only when the
distance between the sink and its current proxy exceeds a certain threshold. The design of such
proxies reduces the cost of pushing data to and querying data from the source and sinks proxies.