In PEGASIS, chained construction formed by greedy algorithm shorten the transmitting distance, However, the long chains bring greater delay and larger dependence on network topology. PEGASIS采用的贪婪算法所形成的链式结构减少了发送数据的距离和数量,降低了能耗;然而长链结构也带来了较大的延时和对网络拓扑的依赖性。