# An Efficient and Reliable Algorithm for Wireless Sensor Network
## 3 Proposed Methodology
### Core Election Process  
Core election process affect the performance of the routing scheme because inappropriate core election procedure declines the network performance in term of network resources. Traditionally, random based selection and connectivity-based selection approaches select the core of the group. In the former approach, the core is selected on random generated number to begin the communication for specific group. The core is selected without any predefined parameters and pre-defined information. Hence, the node with a less battery energy, a smaller number of connected nodes and with inadequate position can be nominated as core node. This inadequate selection of the core node will increase the core failure and hence increases the reconfiguration process. This increase in the reconfiguration process increases the overhead, congestion, packet drops and network resources quickly. To resolve the issue in random based approach, connectivity-based approach is introduced, in which the core node is elected only on number of connected neighbors. hence a node with appropriate position is selected as core node for the group. The problems occur in this approach when the group sizes increase. This increases in the group size will exhaust the energy of the core node quickly and again the failure of the core node increases and hence increases the reconfiguration process. In both the approaches, the frequent core failure affect the QoS based applications. However, in this approach the core is selected on multiple parameters such as battery capacity, sequence number, number of connections and position. Hence, the core with best position and maximum battery capacity is selected  
Figure 1: Block Diagram of the Proposed Protocol.  
as a core node with the increase in the lifetime of the core node. this will also reduce the core failure and hence decreases the re-election process for another core.  
In core election process, nodes \"\(n\)\" is equally distributed using random topology with the velocity of 0-Vmax. Initially two conditions occur. First, if \(n\) wishes to become a member of the already existed group, then it will join the group having their own core node because the existed core node was continuously broadcasting the SD messages within the receiver group. The SD messages are further broadcasted by the group member to reach to every node within the vicinity of the group. These messages are received to node \(n\) through any group member m. Hence, node \(n\) joins the group as defined in the SD message and actively participating tin the group. Secondly, in the absence of the receiver group, the node \(n\) will declare himself as a core node and broadcasting the SD message as a core node to inform others node to join the group. After formation of the receiver group, the formation of the mesh is started as shown in Section 5.  
Now when the core node fails then the proposed core election will start. the members of the group will be aware from the core failure announcement (CFA). The CFA is communicated within the group members through GR and IR if GR and IR did not receive the SD within the predefined threshold i.e., three consecutive SD messages. After the core failure, a core election message (CEM) is broadcasted in the group to select the best possible receiver as a core node in term of battery capacity, sequence number, number of connections and position. Now to find out the best possible core node a core election request message is broadcasted in the group. In reply, the group members will response through core election reply message. Now all the group members will be aware from the status of each other in term of battery capacity, sequence number, number of connections and position as a result a best possible node is selected as a core node. The core election process is shown in Figure 2.  
Figure 2: Core Election Process.