# Research Challenges for the Internet of Things: What Role Can OR Play?
## 3 How can OR Support the Future IoT?
### Intelligence and Context Awareness in the IoT
Our root definition of a simplified \"Home Security Service System\" is as follows:  
_\"A system to provide home security by, when activated, collecting primary security sensor data including entry and exit of people, movements in the property and CCTV images of areas of the property, fusing sensor data, deciding if a security threat is likely, deciding appropriate responses to take to security threats by means of a context model and generated secondary threat data, executing chosen responses, and archiving of sensor and incident data\"._  
This conceptual model arguably contains the minimum necessary set of activities that are required by the root definition. As discussed by [PERSON] [114], the root definition specifies \"what\" is done, and the conceptual model depicts \"how\" it is done. You will note that various types of information are input to this conceptual model (represented in Figure 4 by heavy arrows) and a \"context model\" is also used by three of the activities. The input information may be used to determine the context or be required for activities independently of the context. Our root definition does not specify \"how\" the context model works, but it does specify that a context model will be used to decide \"how\" the system will respond to security threats. In Figure 4 some options, not specified in the root  
Figure 3: A Soft Systems Methodology (SSM) abstract conceptual model. definition, are annotated on some activities for understanding only. Also some mathematical logic statements (IF... THEN... ELSE) are annotated on the context model to clarify how it might work in this application, for understanding only. In the real world (as opposed to the conceptual world of our model) a context model can be a very complex computer program, and can be classed as either an Expert System (which often uses mathematical logic), an Operations Research Model (such as a Multi-Criteria Decision Model or a Discrete-event Simulation Model) or something else. In our illustrative conceptual model the context model is used for three activities:  
* Fusion of sensor data;
* Deciding if a security threat is likely; and
* Deciding on appropriate responses to a threat  
Fusion of sensor data is, in general, a process that integrates multisource heterogeneous data from multiple sensor measurements in order to improve processing efficiency and provide advanced intelligence [116]. Deciding if a security threat is likely is a process that may use a variety of techniques, usually based on probability theory. Deciding on appropriate responses to a threat is a process that combines the context information deduced from secondary sensor data (in our simple example this includes the security threat probability and location) together with other data needed for responses  
Figure 4: SSM Conceptual Model of a Simplified Home Security Service System. to a threat, usually stored on a repository. A comprehensive survey of context-aware computing for the IoT is given by [PERSON] et al. [117]. This covers many technical issues including the categories of context information, primary and secondary context data and context reasoning decision models. We note from the last of these topics that the simplest, most straightforward and most popular method of context reasoning is in terms of rules (which have an IF... THEN... ELSE format), as depicted in Figure 4. These technical details are beyond the scope of this paper; our SSM conceptual model is intended to illustrate the feature of SSM of being able to make sense of complex problem situations. In principle, the root definition could specify the specific nature of the context model, i.e., which of an alternative set of context models is used, or give more detail on \"how\" any of the activities in the conceptual model are carried out. [PERSON] et al. [116] discuss two main types of data fusion, one using mathematical or computational methods and the other using semantics derived from representations of sensor data and sensor observations.