###### Abstract  
The recent development of wireless communications has prompted many diversified applications in both industrial and medical sectors. Zigbee is a short-range wireless communication standard that is based on IEEE 802.15.4 and is vastly used in both indoor and outdoor applications. Its performance depends on networking parameters, such as baud rates, transmission power, data encryption, hopping, deployment environment, and transmission distances. For optimized network deployment, an extensive performance analysis is necessary. This would facilitate a clear understanding of the trade-offs of the network performance metrics, such as the packet delivery ratio (PDR), power consumption, network life, link quality, latency, and throughput. This work presents an extensive performance analysis of both the encrypted and unencrypted Zigbee with the stated metrics in a real-world testbed, deployed in both indoor and outdoor scenarios. The major contributions of this work include (i) evaluating the most optimized transmission power level of Zigbee, considering packet delivery ratio and network lifetime; (ii) formulating an algorithm to find the network lifetime from the measured current consumption of packet transmission; and (iii) identifying and quantizing the trade-offs of the multi-hop communication and data encryption with latency, transmission range, and throughput. Zigbee; testbed; experimental; wireless sensor network; power consumption; RSSI; latency; throughput +
Footnote †: journal: Sensors  
222222324523  
Zigbee specifications. The NWK layer defines the architecture of the network, routing protocols, and security and, thus, encryption and decryption of the transmission. The APL layer has three sub-layers, namely application support, application framework, and the Zigbee device object. The application support sublayer interfaces the NWK layer with the APL layer whereas the application framework forms the environment to host the application objects. On the other hand, the Zigbee device object sublayer allows advanced networking along with device and service discovery features [7]. Zigbee is a short-range communication standard based on personal area network (PAN) and operates on the industrial, scientific, and medical (ISM) band of 2.4 GHz [8]. It also operates on 868 and 915 MHz frequency bands with the data rate ranging from 20 to 250 Kbps. It operates on 27 different channels, of which 16 are in 2.4 GHz, 10 channels are in 915 MHz, and 1 channel is in the 868 MHz band [9; 10]. The networking characteristics of Zigbee are depicted in Table 1. Zigbee is used in different interesting real-world applications, such as seismic data acquisition, the mining ventilation system, radio frequency fingerprinting, and different biomedical applications [11; 12; 13; 14; 15]. Due to its interoperable standards and low power operation modes, Zigbee has been popular in indoor, industrial, and outdoor applications. Thus, it has drawn the attention of both industry and academia. Extensive research is being conducted to improve the applicability, network optimization, and performance of Zigbee. The performance of Zigbee depends on various parameters, such as transmission power, deploying scenario, transmission distance, data encryption, baud rates, and the number of hops for the communications. Variations on these parameters greatly affects the performance metrics, such as latency, throughput, link quality, and power consumption. For optimal designing of the network, a clear understanding of the behaviors of these preference metrics corresponding to the above-mentioned parameters is necessary. While research has been conducted to identify the performance analysis of Zigbee, the existing research does not present a comprehensive evaluation for both indoor and outdoor environments while considering all the performance metrics. Encryption is another important factor that provides secured communication with Zigbee but limits the performance of the Zigbee in terms of latency, throughput, and power consumption.