# Performance and Challenges of Service-Oriented Architecture for Wireless Sensor Networks
## 7 Service-Oriented Architectures Approaches for WSNs
### Open Geospatial Consortium with Sensor Web Enablement (OGC SWE)  
Recently, internet services have applied Geographic Information Systems (GIS) that support environmental observations such as weather, a fire alarm, and indoor surveillance systems. As introduced in [68], a WSN Application Service Platform (WASP) is a novel sensor control service with web/GIS based architecture [68]. The WASP (acting as a cloud service) manages data through many data recovery points by sensors that are sent to the server for query by the user. The users are not able to identify between raw and processed data, which results in the loss of necessary information. The WASP is used to manage data and provides various mechanisms, such as data presentation, remote control functions, and security. The limitation of this approach is addressed in [69]; the sensor web enablement was developed to provide a solution for raw data identification and issues related to the mashup between WSN applications. The Sensor Web Enablement (SWE) is based on the Data Observation and Event Notification framework (SWEDOEN) [69] and has been used for smart home applications. This framework has a flexibility of application with WASP and can assign the action and message flows between SWE components. These approaches are not providing mechanisms for a WASP with GIS web service to handle large heterogeneous data in real-time. The middleware can handle a massive amount of this data by using different interfaces, languages, and content messages to convert data to fit the users' needs. The accuracy and performance of their approach is not considered. Moreover, OGC SWE s capable of real-time monitoring. The integration of WSNs into SOA by using a web service proxy linked to high-level SWE to low-level sensor platforms is presented in [70]. OGC SWE is applied for the sensor description, and observation with open Message Queue Telemetry Transport (MQTT) provides a suitable solution for low-level uplink from the WSN to the sensor web. The communication at the proxy layer is done through MQTT. The MQTT is used to solve the issue of one-way communication by using bidirectional communication for OGC SWE. This system is required for WSNs to have web-enabled remote management platforms, which allow data management API to manage and configure WSNs. The Sensor Planning Service (SPS) only describes the ideas but no real world tests were shown. The OGC SWE standard has challenges such as performance, robustness, and reliability. In [71], SOA provides Sensor Node Management Cloud (SeNoMa-cloud) software, which is extended on a proposed framework in [70]. SeNoMa is designed to manage the WSN configuration. The system deploys nodes in different locations of interest, for example, crop fields, and then assigns a sensor to the nodes, locates login, and transfers periods. The GeoSense system is used as a tool for clients to collect, analyze, and visualize the data. The system has many sensor nodes and base stations and can easily manage a WSN using SeNoMa-cloud by a virtual private network. The development of SeNoMa-cloud has to be suitable with OGC SWE. The OGC SWE has one-way communication in which it can only receive data/services from SeNoMa and send it to the cloud. This approach provides advantages for WSN management on multiple stations and deals with raw data. The sensor node management mechanism was designed to manage WSN configuration. This approach is limited because it increases overhead by using XML-based web service. An increase in the overhead could cause data transmission with low bandwidth. OGC SWE provides mechanisms to detect and determine failure, in order to reconfigure the system so that it can continue execution. WSNs are widely used in many studies, such as agriculture control applications and natural resources. Different architectures are used in agriculture to provide an efficient platform for making decisions on how to manage crop planning.