Data Dissemination Protocol for Mobile Sink in Wireless Sensor Networks

Algorithm 1

Neighbor discovery.

Data structure for any sensor node 𝑥:

𝑁𝐵𝑅(𝑥): neighbor set of node 𝑥, initialized to 𝜙.

𝑅𝑁(𝑥): the set of neighbors of node 𝑥, which are willing to be the relay node, initialized to 𝜙.

𝑊𝐼𝐿𝐿_𝑥: either true or false depends on the willingness of node 𝑥 to become a relay node.

𝑁𝐵𝑅_𝐷𝐸𝑇_𝑆𝐸𝑁𝑇_𝑥: set to true when the sensor node 𝑥 sends NBR_DET packet, initialized to false.

Node 𝑥 receives following packet from node 𝑦:

NBR_DET: ⟨NBR_DET, 𝑖𝑑_𝑦,𝑊𝐼𝐿𝐿_𝑦⟩

if (𝑦∉𝑁𝐵𝑅(𝑥)) then

 𝑁𝐵𝑅(𝑥)←𝑁𝐵𝑅(𝑥)∪{𝑦};

 if (𝑊𝐼𝐿𝐿_𝑦==𝑡𝑟𝑢𝑒) then

   𝑅𝑁(𝑥)←𝑅𝑁(𝑥)∪{𝑦};

 end if

 if (𝑁𝐵𝑅_𝐷𝐸𝑇_𝑆𝐸𝑁𝑇_𝑥==𝑓𝑎𝑙𝑠𝑒) then

   𝑁𝐵𝑅_𝐷𝐸𝑇_𝑆𝐸𝑁𝑇_𝑥←𝑡𝑟𝑢𝑒;

   𝑙_𝑟𝑏(NBR_DET, 𝑖𝑑_𝑥,𝑊𝐼𝐿𝐿_𝑥);            ⊳ Broadcast NBR_DET packet

 else

   Drop the packet;

 end if

else

 Drop the packet;

end if