Sensor node for selecting and transmitting a data packet to a relay node

A sensor node for selecting a relay node for transmitting a packet from the sensor node to a destination node in a wireless sensor network including a plurality of nodes, comprising circuitry configured to:

• determining a size of a bounding box surrounding the destination node based on a distance between the first node and the destination node, and/or a density of the plurality of nodes of the wireless sensor network;
• wherein the bounding box has a shape of a circle centered at a location of the destination node, and wherein the size of the bounding box is determined based on a density of the plurality of nodes of the wireless sensor network;
• establish a transmission angle at the sensor node based on the bounding box, wherein a location of the sensor node is the vertex of the transmission angle, and the transmission angle is a minimum angle to include the bounding box within two sides of the transmission angle;
• select a first node as the relay node, wherein the first node has a highest remaining energy level among energy levels of neighbor nodes of the sensor node within the transmission angle;
• and
• transmit the packet from the sensor node to the destination node via the relay node.