The data delivery delay is a significant measure in wireless sensor networks when the users focus on data freshness. In the previous work, two approaches named: Unusual Message Delivery Path Construction (UMDPC) and Improved-UMDPC (I-UMDPC), target on delivering unusual message to mobile nodes within the allowed latency. The data collection system consists of a set of sensor nodes (S nodes) to detect the environment, a set of mobile nodes (M nodes) attached to buses to collect sensory data, and a set of B nodes deployed at bus stops to assist data delivery. The goal of this work is to investigate the influence of B node coverage on the delay sensitive data delivery performance of the two existing approaches. In this paper, the B node coverage is indicated by the average hop distance between cluster heads and B nodes. We focus on seeking the minimum achieved allowed latency under different B node coverage and demonstrate the results through simulations.