Abstract
in the last decade, the vehicle flow raises faster than road infrastructure in urban areas. Consequently, traffic problems are increasing affecting people’s safety and comfort. Considering this literature, a various number of solutions is considered to deal with traffic problems using VANET. The most important issues in this field concern providing VANET routing protocols in a high speed environment. In this paper, the topology-based protocols were considered for the study. As known, the topology-based category is divided into three subcategories: reactive, proactive and hybrid. First, the principal characteristics are described and research challenges in VANET environment are discussed. Then, the performance of each topology-based routing protocol is evaluated and described in details. A comparative table of all protocols cited is, also, drawn up comparing protocols to each other. Finally, challenges and issues in topology-based routing protocols were discussed.