Alarm system applications may have both a synchronous and an
asynchronous behavior; i.e., they may be periodically queried by a
central control application (e.g., for a periodical refreshment of
the network state) or send a message to the control application on
their own initiative.
When a node (or a group of nodes) identifies a risk situation (e.g.,
intrusion, smoke, fire), it sends an alarm message to a central
controller that could autonomously forward it via the Internet or
interact with other network nodes (e.g., try to obtain more detailed
information or ask other nodes close to the alarm event).
Finally, routing via battery-powered nodes may be very slow if the
nodes are sleeping most of the time (they could appear unresponsive
to the alarm detection). To ensure fast message delivery and avoid
battery drain, routing should be avoided via sleeping devices.
3. Unique Routing Requirements of Home Automation Applications
Home automation applications have a number of specific routing
requirements related to the set of home networking applications and
the perceived operation of the system.
The relations of use cases to requirements are outlined in the table
below:
+------------------------------+-----------------------------+
| Use case | Requirement |
+------------------------------+-----------------------------+
|2.1. Lighting Application in |3.2. Support of Mobility |
|Action |3.3. Scalability |
+------------------------------+-----------------------------+
|2.2. Energy Conservation and |3.1. Constraint-Based Routing|
|Optimizing Energy Consumption | |
+------------------------------+-----------------------------+
|2.3. Moving a Remote Control |3.2. Support of Mobility |
|Around |3.4. Convergence Time |
+------------------------------+-----------------------------+
|2.4. Adding a New Module to |3.4. Convergence Time |
|the System |3.5. Manageability |
+------------------------------+-----------------------------+
|2.7. Healthcare |3.1. Constraint-Based Routing|
| |3.2. Support of Mobility |
| |3.4. Convergence Time |
+------------------------------+-----------------------------+
|2.8. Alarm Systems |3.3. Scalability |
| |3.4. Convergence Time |
+------------------------------+-----------------------------+