**2.1. Wireless MRSN network topology**

Fig. 1 depicts tandem network topology of the MRSN, the most basic and simplest model, which enables us to make an analytic model. The results can be extensible to other topologies that are more complex. In such kind of network, all the robots deployed statically in a flat area and have same role. The robots are allocated omni-directional antenna for wireless communication and have the same transmission ranges. When a robot senses data, it transmits the data to the sink, if the data could not get to the sink by one hop; the robot sends the data to the sink by multi-hop way.

**Figure 1.** Tandem Multi-Robot Network
