In sensor networks, time synchronization between sensor nodes is important because it affects not only the efficiency of information gathering but also energy consumption. Since sensor network environments and sizes change at varying rates, different time synchronization techniques are required for different networks. The pulse-coupled oscillator (PCO) model can be used to achieve local interactions between individuals for the synchronization of entire networks. Other methods also exist, such as the multi-hop reference broadcast synchronization (RBS) method which synchronizes the entire network by transmitting the differences in the timers of reference nodes through networks divided into clusters. We compare here the influence of jitter delay and packet loss resulting from the lower layer protocol on these two techniques. We also investigate the influence on the performance of both methods on network size and wireless channel quality. The simulation results show the conditions in which each method performs better.