ITU‐T's Technical Reports and Specifications 253 Security Monitoring Security monitoring networks are composed of nodes that are placed at fixed locations throughout an environment that continually monitor one or more sensors to detect an abnormality. A key difference between security monitoring and environmental monitoring is that security networks are not actually collecting any data. This has a significant impact on the optimal network architecture. Each node has to frequently check the status of its sensors but it only has to transmit a data report when there is a security violation. The immediate and reliable communication of alarm messages is the primary system requirement. Additionally, it is essential to confirm that each node is still present and functioning. If a node was to be disabled or fail, it would represent a security violation that should be reported. For security monitoring applications, the network must be configured so that nodes are responsible for confirming the status of each other. One approach is to have each node be assigned to peer that will report if a node is not functioning. The optimal topology of a security monitoring network will look quite different from that of a data collection network. It is reasonable to assume that each sensor should be checked approximately once per hour. Combined with the ability to evenly distribute the load of checking nodes, the energy cost of performing this check would become minimal. A majority of the energy consumption in a security network is spent on meeting the strict latency requirements associated with the signaling of the alarm when a security violation occurs. Once detected, a security violation must be communicated to the base station immediately. The latency of the data communication across the network to the base station has a critical impact on the application performance. Users demand that alarm situations be reported within seconds of detection. This means that network nodes must be able to respond quickly to requests from their neighbours in order to forward data. Currently there is a new generation of autonomous 3G sensors equipped with video cameras that enable the development of new security, surveillance and military applications, the wireless sensor network platform for the Internet of Things. These new video camera sensors, in conjunction with the 3G communication module, allow the creation of sensor nodes that transmit both discrete data gathered by analog and digital sensors and complex streams of real time information, such as photos and video, to servers in the Cloud. Figure 32 – 3G sensors stream photo and video to the Cloud for new security applications