## 6 Layer-Based Adjustment (LBA)-TANVEER  
Most of the experiments have been done in deep and shallow water deploying nodes for different purposes such as oil exploration and mineral findings and for some safety-critical applications like [43; 44; 45; 46; 47; 50; 53]. When the environment is enough complex, then the deployment of nodes in random order is not the rational decision; therefore, to avoid as well as accurate detection of empty regions between the nodes the layer-based adjustment of the nodes is aligned for our experiment. All the nodes are deployed in equal layers with multi-sink architecture in such a way that every layer assigned with a unique '\(ID\)'. Each sensor node gets a layer '\(ID\)' by broadcasting the '_Hello Packet_ (\(HP\))' from the sonobuoys. As all the sensor nodes are below the sonobuoys, so it is easy to attempt the layer '\(ID\)' so that each node will be uniquely identified by receiving the '\(HP\)'. In order for each rebroadcasting mechanism, the decrement is applied by the total layer count field of the '\(HP\)'. The numbering of the '_layer-\(ID\)'_ is assigned in ascending order from top (sonobuoys) to bottom (anchored nodes) so that the first layer is the closest layer towards sonobuoys and so on, and this is continued until the whole nodes of the network are assigned a '_layer-\(ID\)'_.  
Initially, the '_layer-ID'_ will be static until the sonobuoys send the next update after a specific time interval. The nodes that directly receive the '_HP_' from sonobuoys will be considered the first layer, and with the decrement of one in the total layer, count field rebroadcast the packet for other below nodes of the first layer. Hence the second decrement is for assigning the '_ID_' for the second layer nodes until the total layer count field becomes zero. As the counter field becomes zero, the further broadcasting of '_HP_' is stopped. All sonobuoys that usually present on the surface of the water have fixed static '_layer-ID_' that is '0'. Broadcasting is started with the total layer count field value that is '9', and the ordinary nodes that is 'N1 to _N6_' received the '_HP_' directly from the sonobuoys and were assigned the '_layer-ID '1_'. with the decrement of 1 the nodes 'N7 to _N12_' received '_HP_' from the upper layer nodes and were assigned the '_layer-ID '2_'.  
Meanwhile, this will continue until the nodes of the last layer get '_ID_'. In case the nodes received multiple '_HP_', the Tri-angular nearest vector approach is used to compare the value of the '_Max-Layer-count_' field of '_HP_'. If the field value is the same, take one '_HP_' into account and discard the other '_HP_', and with different '_Max-Layer-count_' field values, the nodes chose only the packets with greater value in the field and discarded other packets. Figure 3 presents the overall scenario of LBA-TANVEER, and Algorithm 1 discusses the assigning of layers '_ID_' in LBA.  
Figure 3: Layers-Based Adjustment (LBA) to ordinary nodes.  
```
1.Procedure ASSIGNING LAYERS (Source, Sonobuoys (Sn))
2.Total Layers (TL) = 9
3.IF HP: Hello Packet notification having seq Layer-ID
4.If Own-Layer-ID = 00
5.For n = 1
6.if\(n\in N\) && \(s\in Sn\)then
7.HP.Coordinates \(\gets N\) (\(x\), \(y\), \(z\))
8.HP.Add (seq layer-ID (\(N\) ID (\(x\)), (\(y\)), (\(z\))))
9.For (\(N\) (\(l_{1}\))(\(N\) (\(l_{2}\)) \(\in P_{ACK}\)do
10.Assigning Layer-ID
11.endif
12.End For
13.IF (\(\mathit{Own}\)-Layer-ID \(\leq\) n)
14.Discard HP
15.Else
16.Own-Layer-ID = n
17.n ++
18.Broadcast HP further
19.End IF
20.End IF
21.End If
22.End for
23.No further broadcast for this Sink-HP
24.End Procedure
```  
**Algorithm 1**Layer-Based Adjustment of Nodes.