# Design and Implementation of a RFID Reader/Router in RFID-WSN Hybrid System
## 6 Conclusion  
In this paper, we combine RFID technology with ZigBee technology to design both the hardware system and software application of RFID reader/router based on MFRC522 and CC2530. implemented RFID reader/router realizes bidirectional transmission of communication data and makes system networking more flexible. Because the network has router nodes, it can avoid the problem of energy imbalance in networks. At the same time, the system has a good scalability and terminal nodes are small, cheap, and easy to deploy. The RFID reader/router developed could be used in the existing network according to the application requirement, so that a bigger wireless sensor network is achieved. In indoor and outdoor environments, the reliability of the wireless RFID reader/router is tested. The packet loss rate is less than 3% through a transmission distance of 80-100 m outdoors and 30-50 m indoors. The system overcomes many shortcomings of the traditional RFID reader, such as short distance, poor anti-interference, susceptibility to environmental impacts.  
Meanwhile, CC2530 chip is adopted in the system as the micro controller to control the data transmission, and control reading and writing operations of the RF module on electronic tags. This not only overcomes the drawback of high cost in using two kinds of micro controller, but also eliminates the hassle of wiring and saves energy. Experiment shows that the system has a high stability, a long identification distance, an applicable flexibility and a good scalability. It is of significant economical and practical value.  
**Author Contributions:** [PERSON] wrote the manuscript; [PERSON] and [PERSON] provided relevant information, discussed the data, and corrected the manuscript; and [PERSON] revised the manuscript. All authors have read and approved the final manuscript.  
**Acknowledgments:** This work was supported by Science and Technology Correspondent Research Program of Tianjin Municipal Science and Technology Commission in 2016, China, under Grant 16 JCTJPJC52500.  
**Conflicts of Interest:** The authors declare no conflicts of interest.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Test Number**} & \multirow{2}{*}{\
\begin{tabular}{c} **Test** \\ **Environment** \\ \end{tabular} } & \multirow{2}{*}{**Test Distance**} & \multicolumn{2}{c}{**Number of**} & \multirow{2}{*}{
\begin{tabular}{c} **Number of** \\ **Tests for** \\ **Commands** \\ **(Read, Write)** \\ \end{tabular} } & \multirow{2}{*}{**Number of**} & \multirow{2}{*}{**Packet Loss**} \\  & & & & & **Cammands** \\ \hline
1 & indoor & 30 m & 50, 50 & 50, 50 & 0 \\
2 & indoor & 40 m & 50, 50 & 49, 50 & 1\% \\
3 & indoor & 50 m & 50, 50 & 48, 49 & 3\% \\
4 & indoor & 55 m & 50, 50 & 45, 43 & 12\% \\
5 & outdoor & 80 m & 50, 50 & 50, 50 & 0 \\
6 & outdoor & 90 m & 50, 50 & 50, 49 & 1\% \\
7 & outdoor & 100 m & 50, 50 & 49, 48 & 3\% \\
8 & outdoor & 105 m & 50, 50 & 44, 43 & 13\% \\ \hline \hline \end{tabular}
\end{table}
Table 1: The test results of transmission distance between the ZigBee sensor node and the RFID reader/router node.