In this mobility pattern, nodes may accelerate or decelerate their speed on the basis of node density and data generated by the upcoming nodes. In this motion, nodes move up and down on a vertical line and their speed is influenced by node density and traffic generation rate of normal nodes. Courier nodes move in pairs as mobility of CN1 and CN3 is in one direction while CN2 and CN4 move towards other direction. This type of motion pattern ensures that these nodes must overlap and communicate with each other at the overlapping area. In order to illustrate the motion of a courier node c consider it is at position yc; its new position yt after time t can be determined by following equation. (25)dyc2dt2+1tdycdt+yc=1t2×yt