Effect of MAC type and speed on neighbor discovery in wireless train networks

In this paper, a wireless neighbor discovery (ND) process in a linear topology of a high-speed train backbone network is studied. A key step that enables communication in such a network is that of topology discovery (TD), whereby nodes learn in a distributed fashion the physical topology of the backbone network. ND, where each individual node discovers their right and left one-hop neighbors is the first and key step in TD. While the current standard for train inauguration assumes wired links between adjacent backbone nodes, this paper investigates the more challenging scenario in which the nodes communicate in wireless-fashion based on IEEE 802.11 or slotted-ALOHA. A network simulation using NS-2 software is developed for the 802.11-based (and slotted-ALOHA based) wireless ND. The network simulation is applied to analyze performance metrics, such as ND time and ND success rate as a function of various parameters.