Continuous Neighbor Discovery in Asynchronous Sensor Networks
Abstract:
In most sensor networks the nodes are static. Nevertheless, node connectivity is subject to changes because of disruptions in wireless communication, transmission power changes, or loss of synchronization between neighboring nodes. Hence, even after a sensor is aware of its immediate neighbors, it must continuously maintain its view, a process we call continuous neighbor discovery. In this work we distinguish between neighbor discovery during sensor network initialization and continuous neighbor discovery. We focus on the latter and view it as a joint task of all the nodes in every connected segment. Each sensor employs a simple protocol in a coordinate effort to reduce power consumption without increasing the time required to detect hidden sensors.
Algorithm:
AN EFFICIENT CONTINUOUS NEIGHBOR DISCOVERY ALGORITHM:
In this section we present an algorithm for assigning HELLO message frequency to the nodes of the same segment. This algorithm is based on detecting all hidden links inside a segment. Namely, if a hidden node is discovered by one of its segment neighbors, it is discovered by all its other segment neighbors after a very short time. Hence, the discovery of a new neighbor is viewed as a joint effort of the whole segment. One of the three methods presented in Section is used to estimate the number of nodes participating in this effort.
Suppose that node u is in initial neighbor discovery state, where it wakes up every TI seconds for a period of time equal to H, and broadcasts HELLO messages. Suppose that the nodes of segment S should discover u within a time period T with probability P.
Existing System:
Initial neighbor discovery is usually performed when the sensor has no clue about the structure of its immediate surroundings. In such a case, the sensor cannot communicate with the gateway and is therefore very limited in performing its tasks.
Disadvantages:
1. In networks with continuously heavy traffic.
2. Long-term process.
3. Greater expense of energy than required in our scheme.
Proposed System:
We distinguish between neighbor discovery during sensor network initialization and continuous neighbor discovery. We focus on the latter and view it as a joint task of all the nodes in every connected segment. Each sensor employs a simple protocol in a coordinate effort to reduce power consumption without increasing the time required to detect hidden sensors.