Research Article

Alert: An Adaptive Low-Latency Event-Driven MAC Protocol for Wireless Sensor Networks

Algorithm 1

Adaptive alert protocol.
(1) Get 𝑀 o p t for some guess on number of nodes 𝑁 g u e s s ,
  ⟨ 𝑀 o p t ⟩ = g e t 𝑀 ( 𝑁 g u e s s ) .
(2) Start with some initial value of 𝑁 = 𝑁 i n i t
(3) Get some estimate on value of 𝑄 .
(4) Get 𝐏 , and expected number of frames needed, 𝐹 ,
   based on current estimate 𝑁 and for 𝑀 o p t ,
  ⟨ 𝐏 , 𝐹 ⟩ = g e t 𝐏 ( 𝑁 , 𝑀 o p t )
(5) while message not read do
(6) for frame 𝑑 = 1 to 𝐹   do
(7)  for all slots in frame 𝑑   do
(8)   Execute protocol for calculated 𝐩 ( 𝑑 ) for frame 𝑑
(9)   Terminate execution if message read and reset
    to initial state
(10)  end for
(11) end for
(12) Increase estimate by a constant factor 𝑁 = 𝑁 + 𝐢 i n c f
(13) Get 𝐏 , and expected number of frames needed, 𝐹 ,
   based on current 𝑁 for 𝑀 o p t
    ⟨ 𝐏 , 𝐹 ⟩ = g e t 𝐏 ( 𝑁 , 𝑀 o p t )
(14) end while