Wireless Sensor Networks M Homework #1
Part 1 Consider two sensor devices (one transmitter and one receiver) IEEE standard- compliant. Assume that the Loss in dB between the two nodes at distance d, is given by: L[dB]=k 0 +k 1 ln(d) Where k 0 =40 dB, k 1 =17.37 and ln is the natural logarithm. By setting the bilateral power spectral density of the receiver, N 0 = 8* W/Hz and the transmit power, P t = 0 dBm, which is the maximum distance between the two devices, such that the Block Error Rate, BLER is lower than 10 -2, when a data block composed of 10 Bytes is transmitted?
Part 2 Two IEEE sensor nodes (one transmitter and one receiver) are d meters apart at a height of 1 m above the ground. When the transmitter takes a sample from the environment, it encodes it with 4 bytes and transmits it through a data block composed of 30 bytes overall. The link uses channel 24 of IEEE , with transmission power set at 0.1 mW. In the presence of obstacles (like ground) a propagation coefficient, , equal to 2.5 should be considered. The bilateral power spectral density of the receiver, N 0 = 9* W/Hz The energy consumed by the transmitting node to send the data is 60 J. The initial battery charge is J. The energy consumed by the receiving node to receive the data is 50 J. Its initial battery charge is J. 1)By setting the transmitter and receiver distance, d, to the maximum value satisfying the free space conditions, compute the BLER 2)Now set d=40 m and compute the BLER 3)Assuming the application requires to receive one sample every 16 ms, compute the link lifetime