Question 2 (15 marks) A B d-50ml C D E Consider a linear wireless sensor network composed of 5 nodes (see reference topology above). Assuming that: [1] Each node is d = 5 [m] away from its closest neighbour; [2] The energy required to operate the radio module for each bit (both for receiving and transmitting) is E =50 [nMbit]; [3] The energy required to successfully transmit a message over distance dis E (d ) = kd' [nJbit], where k =1; [4] The network uses messages that are 2000 [bits] long Calculate whether it is more energy efficient to use direct or multi-hop transmission for sending a messagerom nodeA to nodeE. For the same network as the previous exercise: (a) explain in terms of complexity (i.e. using asymptotic analysis) the differences between the two strategies with respect to energy dissipation; (b) find the number of sensor nodes for which the direct transmission strategy consumes the same amount of energy as the multi-hop transmission strategy