DISTRIBUTIVE SPECIALIZATION
The third strategy is to distribute certain specialized operations to a limited number of devices, sometimes referred to as distributive specialization (DS). This means that WSN devices and the network are configured in such a way as to distribute certain operational functionality among a very limited number of “helper” devices within a network. This is in contrast to building all of the functionality into most of the devices of a certain type. Common features that lend themselves to this distributive specialization strategy include:
• The management and distribution of security keys (a Trust Center device)
• The monitoring and management of the physical channels (a Channel Manager)
• The collector and aggregator of network data (a Collector device)
• The keeper and distributor of routing information (a Route Concentrator device).
The network’s and its cooperating devices’ collective ability to distribute these operations can have an impact in reducing the overall average cost of each device. In practice, the RFD devices would be the predominantly low-memory, lower-cost MCUs. At the same time, “helper” devices would be strategically distributed throughout the network in much smaller numbers to perform some of the more memory-expensive tasks.
IN SUMMARY
Designers can take advantage of three potential strategies for conserving memory in WSNs: using the simplest topology and routing mechanism; designing device features so they can be easily excluded when not required by a particular application; and distributing some specialized services among different devices in the network so as not to burden each device type with all the services.
Employing all or some of these strategies is an effective way to lower the memory- footprint threshold requirements for WSN devices, which in turn can lead to meaningful cost savings for wireless product and network providers.
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