Detection probabilities for satellite automatic identification system with decollision algorithm and spot beam

Abstract

The Internet-of-Things (IoT) networks comprise of the wired, the wireless terrestrial and the satellite networks. The satellite IoT networks can cover areas that are not reachable by the wired and the wireless terrestrial networks. A Self-Organizing Time Division Multiplexing Access (SOTDMA medium access control (MAC) protocol is used for the Satellite Automatic Identification System (S-AIS). This paper analyzes and derives the detection probabilities of the ship vessels from a AIS satellite for the S-AIS with a Decollision Algorithm (S-AIS-DA) as well as with Spot Beam (S-AIS-SB) or both (S-AIS-DA-SB). A simple probabilistic model is used to capture the packet error ratios in these schemes. Numerical results show that the performance gains in the number of ship vessels that can be detected can be up to 132% for the S-AIS-DA scheme that can decode up to 4 packets over a basic S-AIS scheme and up to 131% for the S-AIS-DA-SB scheme that can decode up to 4 packets and with 6 spot beams over the S-AIS-SB scheme. The percentage losses of number of ship vessels that can be detected for these schemes with packet loss ratios as compared with these schemes without packet loss ratios are about 1.1%, 1.1% and 2.9% for a decollision algorithm that can decode in an access slot up to one, two and three packets, respectively. On the other hand, the percentage drops in the detection probabilities of the S-AIS-DA scheme with packet error ratios over that of the S-AIS-DA scheme without packet error ratios and the S-AIS-DA-SB scheme with packet error ratios over that of the S-AIS-DA-SB scheme without packet error ratios for detecting up to 3 packets are 4.6% and 3.8%, respectively.