Connection of Sensor Network with TCP/IP Network , Article -2

Continuing from the previous article ........

Unifying Micro Sensor Networks with the Internet via Overlay Networking is another paper, which proposes to use sensor network overlay over TCP/IP networks. By using such an overlay sensor network can use data centric approach, i.e. assigning unique address to each and every senor node is not essential. The sensor network overlay is formed by extending address less sensor network routing into internet as application overlay. The figure below shows the Sensor network overlay on TCP/IP networks.



Sensor Network Overlay on TCP/IP network.

The nodes in internet with Sensor network overlay are called as virtual sensor nodes, and these help in forming virtual sensor network.
TCP/IP overlay over Sensor Network paper proposes to use TCP/IP stack in the sensor nodes.
The key advantage is that it makes WSN highly compatible with internet as both them will have almost similar protocols running. However this TCP/IP stack can be loaded into sensor nodes which have higher memory and higher processing capabilities. The authors have developed something called as u-IP stack. This is similar to normal TCP/IP stack but with lesser features. The memory required to load the stack is also less compared to full TCP/IP stack. The figure below shows the TCP/IP overlay on WSN.




TCP/IP Overlay on WSN

In yet another paper called “VIP Bridge Method” authors propose to use node centric or location centric WSN. It is not applicable for data centric WSN. This paper uses a VIP Bridge it does mapping between IP address and location address or local address of the sensor node. The sensor nodes will not have IP address configured, but the IP address to each node exists in VIP Bridge. The sensors will be identified in the WSN by the local identifiers the VIP Bridge does the conversion require. The VIP Bridge does translation form sensor network to TCP/IP and vice versa. This paper explains the method to do the conversion. The advantage of this VIP Bridge method is that communication is done between TCP/IP network and WSN using IP address itself and the local sensor identifier is used for communication within the senor networks. The internet users need not know the protocols used in WSN they can use WSN as if it is a normal TCP/IP network. In other words WSN is transparent to internet users. The architecture of the VIP Bridge method is as shown below.




VIP Bridge Architecture.