Design of a Reliable Traffic Control System on City Area Based on a Wireless Network

Design of a Reliable Communication System for Grid-Style Traffic Light Networks

“…Lee et al proposed a channel selection scheme based on the CCA result in the preliminary version of this paper [7]. The idea of CCA-based channel switch and path adaptation is sustained to this paper.…”

“…After all, the schedule for the 3 × 3 grid includes 10 additional listening operations, so the secondary slot assignment has 10 entries [7]. In the meanwhile, when the destination is N 1,0 , N 2,0 , N 0,1 , or N 0,2 , we cannot expect any improvement, as they have no alternative path whose length is equal to the primary one.…”

“…In Figure 3 (a), we assume that N 0,0 is the controller node. When the controller node is located in the arbitrary point within the grid, 4 quadrants can be formed as shown in Figure 3 (b), each of which having the controller node at one corner [7]. Next, 4 quadrants can be mapped or transformed to the network shown in Figure 3 For process control, device-to-device communication is carried out in a pre-scheduled time window.…”

“…This scheme is proven to work quite well on the network having many reliable nodes. However, [7] restrictively assumed that the slot error rate of each link is the same and the split-merge operation, which will be described later, is simply placed to the rectangle closer to the destination. As contrast, this paper generalizes to the case that each channel has its own slot error rate, proposes a method to decide the primary and secondary paths, and addresses how to apply the channel switch operation in each control message path, along with extensive performance analysis results.…”

“…This idea has the limitation that it cannot work for all wireless network topologies [7]. For the idea to be practical, both alternative and primary paths must a sufficient number of nodes in common and also have the same length.…”