# Performance and Challenges of Service-Oriented Architecture for Wireless Sensor Networks
## 9 Analysis
### Service Composition Architectures for WSNs  
Open issues of service composition shows that the adaptive service composition is required to have flexible composition methods that can enhance the scalability when the services are integrated into the network based on their availability. The SCPQ provides QoS requirements and decreases cost and power consumption. On the other hand, SWSN is capable of collecting information and reusing resources. The SCPQ approach does not address service composition languages on its design. In case of adaptive service composition, SWSN is based on web services. Meanwhile, SCPQ focuses on specific methodology such as service composition solution that is provided through the greedy optimal algorithm. However, SCPQ does not address service integration with the IoT, while the SWSN addresses this issue through web service. Table 8 shows the analysis of service composition architectures for WSNs. In conclusion of the conducted analyses, Tables 2-8 represent SOM architectures, SOA, and services composition approaches with their requirements and evaluation of their advantages and disadvantages. The implementation of these approaches offers relative limitations and strengths. These approaches are reinforced through the abstraction level, sensors platform, extensibility, and reconfiguration. In this paper, the disadvantages of implementing a comprehensive framework and its limitations are considered. The main limitations that must be addressed are the heterogeneity of sensors networks, end-to-end security from the sensor to end users, QoS (solved through scalability \begin{table}
\begin{tabular}{c c} \hline
**SOA Approach** & **The Requirements** \\ \hline SODA for Smart Environment [71] & 1. & Support the heterogeneity \\  & 2. & Performance measurement effect on latency. The overhead that is related to SOAP \\  & & message process was small when compared to messages transmission \\ \hline SOA Model for Sensor Networks [72] & 1. & Multi-gateways uses to solve the issue of congestion that generate by using one gateway \\  & 2. & Authentication user \\  & 3. & Data should be located near the users and filter data near to distinction \\  & 4. & Ability to linked various protocols that can be used for WSN \\ \hline WSNs Cloud User Interaction & 1. & NaaS requires the WSN supporting Service-Oriented software architecture \\  & 2. & Non-collaborative [74; 75] \\ \hline FSONA [79] & 1. & Interoperability between service \\  & 2. & Supports QoS and run time \\  & 3. & Integrated with other system \\  & 4. & Service abstraction and discovery \\ \hline SYLPH [64] & 1. & The devices are not requiring any features as large memory to communicate \\  & & with SYLPH \\  & 2. & Improves the system security and efficiency for care services \\ \hline OGC-SWE standards (Web Service) [68; 70] & 1. & SWE standard helps to discovery sensors data and the interoperability \\  & 2. & Supporting the data detection \\  & 3. & Data retrieval increase for WSN through remote control \\  & 4. & Provide user authorized \\  & 5. & SWE standard helps to discovery sensors data and the interoperability \\  & 6. & Supporting the data detection \\ \hline ANDSF & 1. & Solved problem the overhead between access networks and the service registry \\  & 2. & Provide mechanism for updating network states information in real time and \\  & & service description \\ \hline Healthcare Approaches & 1. & Supports efficient information retrieval \\  & 2. & Achieve the desired QoS in WSNs \\  & 3. & Support the heterogeneous and asynchronous \\ \hline Configuration Service [76] & 1. & Adaptation at Runtime \\  & 2. & Reduce cost \\ \hline \end{tabular}
\end{table} 
Table 7: The Requirements and Benefits of Applied SOA for WSNs. and privacy), response time, and throughput. The service discovery mechanism should be available to assure the continuity of the service. It has the ability to discover any failures and replace them with the best available service during runtime.