Wireless Sensor and Actuator Networks: Algorithms and Protocols for Scalable Coordination and Data Communication

8.6 HOME-BASED APPROACHES

Stojmenovic (2002a), and Blazevic et al. (2001), and Woo and Singh (2001) independently suggested flat home-based location service approaches that are similar to Mobile IP and cellular phone network. Hierarchical home-based location service was first proposed by Li et al. (2000). A number of home-based location service, for example, Xue et al. (2001), Viana et al. (2005), Chen et al. (2006), and Kieb et al. (2004), have been proposed so far, by adopting different home region definition methods. They show close analogy to the above pioneer work in design. In this case, below we will cover only the representative Stojmenovic (2002a) and Li et al. (2000) in detail.

8.6.1 Flat Home Region

Stojmenovic (2002a) presented a home-agent-based location service. In this algorithm, an actuator's home agent is a circular area of radius R centered at the actuator's initial position. Here, R is a predefined value proportional to the actuator communication radius. The location of home agent is flooded to the network. Alternatively, hash function is used to find location of home region (Blazevic et al., 2001; Woo and Singh, 2001).

Each actuator sends location update messages toward the center of its home agent by a geographic routing such as GFG (Bose et al., 1999). Once an update message enters its originator's home agent base, it is forwarded in a strictly greedy manner. If greedy next hop cannot be found, current sensor will transmit the message to all the nodes within ...