# Joint Communication-Motion Planning in Networked Robotic Systems
## 1 Introduction and Related Works
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Ref.** & \begin{tabular}{c} **Network** \\ **Topology** \\ \end{tabular} & \
\begin{tabular}{c} **Design Objective** \\ \end{tabular} &
\begin{tabular}{c} **Exploited DoF** \\ \end{tabular} \\ \hline
[3] & Multi-hop &
\begin{tabular}{c} Maximizing communication quality \\ of service \\ Minimizing the total energy \\ consumption \\ Minimizing the total energy \\ consumption \\ \end{tabular} & Mobility \\
[4] & Point-to-Point &
\begin{tabular}{c} Maximizing the strength of receiving \\ signal \\ Maximizing the throughput \\ guarantees to the video streaming \\ Maximizing the long-term \\ throughput \\ \end{tabular} & Mobility \\
[5] & Point-to-Point &
\begin{tabular}{c} Maximizing the strength of receiving \\ signal \\ Maximizing the throughput \\ guarantees to the video streaming \\ Maximizing the long-term \\ throughput \\ \end{tabular} & Mobility \\
[6] & Point-to-Point &
\begin{tabular}{c} Maximizing the throughput \\ guarantees to the video streaming \\ Maximizing the long-term \\ throughput \\ \end{tabular} & Mobility \\
[7] & Multi-hop & \
\begin{tabular}{c} Maximizing the bandwidth-usage \\ \end{tabular} &
\begin{tabular}{c} Mobility, Trans-mit \\ Power \\ Topology \\ Transmit Power, \\ Phase-shift \\ \end{tabular} \\
[11] & Point-to-Point &
\begin{tabular}{c} Minimizing the total energy \\ consumption \\ \end{tabular} & Mobility \\
[12] & Multi-Unicast &
\begin{tabular}{c} Minimizing the service discrepancy \\ among all pairs of robots \\ Minimizing the total energy \\ consumption \\ \end{tabular} & Mobility, Trans-mit \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Contributions on communication-aware motion planning (CAMP) in networked robotic system (NRS). Figure 1: A robot-assisted surveillance scenario. We may conclude that the CAMP proposals have not fully considered the degree-of-freedom exhibited in motion planning and communication planning. Against this background, we propose the joint communication-motion planning (JCMP), which aims at _jointly exploiting the DoF in mobility, space time, frequency and power (MSTFP) dimensions from both the motion and communication components equipped by the robots,_ which also leads to much more fertilized interplays between different dimensions in communication and motion. As a result, the NRS adopting JCMP will _be capable of covering a wider range of application scenarios_ that involve holistic energy control, dynamic access and interference control. In this paper, a robot-assisted surveillance model is considered as shown in Figure 1. The sensing robot, the relay robot as well as the base station are secondary users (SUs) and form a secondary relay system, and a primary user (PU) exists in the same area. If the underlay approach is adopted, the SUs are allowed to use the spectrum of the PU only when the interference generated by the SUs does not exceed the tolerance level of the PU. Hence, when the sensing robot is moving closer to the PU, it has to reduce its transmit power to avoid over-high interference, while the relay robot should strike a trade-off between motion and communication planning. Specifically, moving the relay robot closer to the sensing robot may help improve the source-relay link quality; however, the relay robot is also moving closer to the PU, which not only incurs a higher motion energy consumption, but also leads to a more stringent relay transmit power that degrades the link quality spanning from the relay robot to the base station. Hence, a more sophisticated design on the mobility/communication tradeoff is required, which is as will be shown quantitatively in Sections 2 and 3. The contributions of this paper are as follows:  
1. Based on the OODA loop, we propose a relay-assisted robot surveillance prototype and a cognitive-relay-assisted robot system with interference constraints. We establish the communication system modeling considering the influence of path loss and multi-path fading. 2.