In Network Processing and Data Aggregation in

wild animals are monitored inside a park of several thousands of sq. meters the placementof nodes is totally different from the case of a factory that supervises items in awarehouse.• Particular Traffic patternsA typical communication scenario is as follows: A physical phenomenon occurs neara field of sensors. A big number of sensors events are triggered resulting in the massproduction of messages (containing values, IDs etc.). These messages have to be routedin a multi-hop fashion to a single point, the sink. The routing pattern looks like a reversedmulticast tree where the destination of all the packets is a single node and there aremultiple senders (many-to-one). Figure 7 demonstrates this pattern. This, however, doesnot prevent the flow of data to be in other forms (e.g., multicast or peer to peer). Additionally,since the data being collected by multiple sensors is based on common phenomena, redundantdata will surely be propagated inside the network.A B CEFDGSINKFigure 7. Reverse multicast tree• Robustness to network DynamicsThe nodes inside the area of deployment may change locations (mobile nodes). Thisleads to frequent alternations of the “neighborhood” of a sensor. Moreover, several nodesmay run out of battery or face hardware failures and become dead. The network has tomaintain its connectivity no matter how many or how frequent are the topology changes.• Scalability (Using localized & distributed algorithm)