# Wireless Communication Technologies for Smart Grid Distribution Networks +
## 5 Summary and Conclusions
However, the difficulty of channel modeling is a big disadvantage. Digital Subscriber Line (DSL) and fiber optic communication have also been considered, but these wired technologies are costly for wide-area deployment. Correspondingly, wireless technologies reduce installation costs but have constraints in terms of bandwidth and security options. A large number of sensors are installed along the distribution power line in a wireless sensor network (WSN). WSNs have punctual challenges and requirements, which have been identified in the literature. To address the main bandwidth and energy concerns, WSNs should implement protocols and algorithms designed for limited computational and memory capacities. In addition, the self-healing capacity is important in the environment of a power line. The future IEEE P1777 standard will define the precise requirements and challenges of different technologies. The main challenges for WSNs are the harsh environmental conditions and the energy required to power them. More specifically, the main requirements of WSNs are the security of information, robustness in terms of wide coverage, and reliability to keep the information flowing continuously. This latter feature is very important, as time delays and outages are critical in the power utility grid. Scalability, as the possibility of integrating protocols and grid configurations, is also an important feature in the context of the sensor nodes of different instrumentation and communication technologies. Wireless technologies must address issues such as performance in noisy grid environments, security concerns, the limited range of transmission, low data rates, non-industrial-level availability, and the lack of robust standards for WSNs. The experimental performance of different WSNs in the environment of power lines has not often been addressed in the literature. Some studies have presented the design of protocols for WSNs. ZigBee technology is a very popular technology. The challenge of maintaining accurate clock synchronization between sensors has been clearly identified. In one study, this was accomplished with the IEEE 1588 standard. Apart from measurements of the coverage range, data rate, and latency, the quality of the channel is an important indicator of communication performance. Metrics for achieving this are not yet standardized, but the Received Signal-Strength Indicator (RSSI) in the nodes, Percentage of Successful Reception (PSR), and Packet Reception Rate (PRR) have been used in some studies. Ultimately, a parameter called the Link-Quality Indicator (LQI) (known as the chip error rate) has proven to be a good indicator of the packet reception probability in WSNs. In outdoor environments, 802.15.4 can achieve a transmission success rate of 80% at 400 m, with physical obstacles as the main drawback. Power line currents of 500 A do not affect communication according to the experiments conducted. The complexity of the WSN's communication channel in power system environments has been addressed using mathematical models like the log-normal shadowing path loss. The gathering of data for this model is dependent on the specific communication environment. ZigBee has been tested using this model, showing around \(-105\) dBm of noise in outdoor environments and interference with 802.11 signals in the 2.4 GHz band.