# Retracted: W-GPCR Routing Method for Vehicular Ad Hoc Networks
## 1 Introduction
Location-based routing protocols are divided into the following five main categories:  
1. Routing protocols based on greedy algorithms, such as Geographic Perimeter Stateless Routing (GPSR) [9] and Greedy Perimeter Coordinator Routing (GPCR) [10] protocols. When the source node knows the location of its target node, this type of routing protocol greedily chooses to forward the data packet to the neighbor node closer to the target node until the data packet is successfully sent to the target node. When a node forwards data, it does not need to know the status information of nodes other than the target node and neighbor nodes. This reduces the cost of routine maintenance. When forwarding data, there is only one next-hop node selected, and there is no need to flood forward data. 2. Routing protocols based on mobile prediction, such as DGRP (Directional Greedy Routing Protocol) [11], PDGR (Predictive Directional Greedy Routing) [12], PGRP (Predictive Geographic Routing Protocol) [13], and MPBRP (Mobility Prediction Based Routing Protocol) [14]. In this type of routing protocol, the location of the node is predicted. In the selection of nodes, the reference indexes of the movement direction and position of the nodes are weighed. This can reduce the number of routing hops and end-to-end delay. However, this kind of routing needs to predict the position of the current node and all of its neighboring nodes, which increases the calculation task of the system and increases the network overhead. 3. Routing protocols based on delay tolerance, such as GeoDTN+Nav (Geographic Delay Tolerant Network Routing With Navigator) [15]. This type of routing protocol mitigates the impact of network partitions and intermittent connections through a delay-tolerant store-and-forwardscheme, thereby improving the reachability of routes. However, this kind of routing protocol has a poor real-time performance. When the data packet is cached to a certain node, and there is no suitable opportunity to forward it, the information will be lost due to the excessive accumulation of data packets. 4. Routing protocols based on a combination of topology and location, such as GPCR-D(A Topology and Position Based Routing Protocol in VANET) [16] and HybTGR (Hybrid Routing Protocol Based on Topological and Geographical) [17]. In this type of routing protocol, each network node is assigned a weight based on parameters including the node's moving speed, the life of the routing link, the number of vehicles near the node, and the distance to the target node. According to the weight, the topology or location routing protocol is used. Its implementation is more complicated, and there is the problem of frequent switching of routing protocols, which will increase the overhead of the system network and result in poor real-time performance. 5. Routing protocols based on bionic algorithms, such as EGSR (Enhanced Geographical Source Routing) [18], GSO (Glowworm Swarm Optimization) [19], and ASGR (Artificial Spider-Web-Based Geographic Routing) [20]. This type of routing protocol uses a bionic algorithm to select the optimal path to deliver data packets, which can reduce network overhead and end-to-end delay. However, this type of routing protocol is not suitable for high-speed dynamic scenarios. As can be seen from the above, the latter four routing protocols have the disadvantages of complex algorithm implementation and are not suitable for high-speed mobile Internet of Vehicles. Therefore, this paper studies routing protocols based mainly on the greedy algorithm. The existing routing protocol based on the greedy algorithm is not perfect, and the following drawbacks exist in its implementation:  
* The greedy forwarding strategy has a locally optimal solution when selecting a node. The choice of the next-hop node simply depends on the distance between the judgment node and the target node. There is no global consideration. * The right-hand rule used when the greedy forwarding strategy fails has drawbacks.