A fault detection method, a communication system, and an LSR are provided herein to overcome the inability of performing BFD packet resolution fault detection for multiple nodes in the conventional art. The cleaning element can be transferred from the first functional position into at least one second functional position. The at least one transfer gear is contained within a gear housing. The wireless softswitch is communicatively connected with the plurality of macrocell base stations and the femtocell device, and stores geographic coverage area information for each of the plurality of macrocell base stations.