# EDDA: An Efficient Distributed Data Replication Algorithm in VANETs
## 2 Related Work
### Data Dissemination Algorithms
Spray-and-wait can decrease the network resource consumption while it has similar performance compared to epidemic routing. However, it does not take into account bandwidth and network capacity. In contrast, [PERSON] et al. [36] proposed a resource allocation protocol for intentional delay tolerant network (RAPID), which decided whether to replicate packets whenever two vehicles encountered each other with respect to a given performance metric. RAPID explicitly calculated the effect of replication on the routing metric while considering resource constraints. To tackle the problems that data dissemination could not effectively address broadcast storm and network partition problems simultaneously, [PERSON] et al. [37] proposed a suitable urban multi-hop broadcast protocol (TURBO) that relied exclusively on local one-hop neighbor information to deliver messages under dense and sparse networks. [PERSON] et al. [38] designed a data dissemination scheme, which can disseminate data to a desired number of receivers in VANET (DOVE). The scheme was inspired by processor scheduling treating roads as processors to optimize the workload assignment and improve the efficiency of on-road dissemination. [PERSON] et al. [39] proposed an advanced routing scheme that controls the maximum number of replicas according to the distance between the source node and the nearest base station. They also showed how to decide the maximum number of replicas by analyzing the message delivery reliability of an existing DTN routing scheme. [PERSON] et al. [40] evaluated how many idle resources of LTE could be provided for safety services and how safety applications impacted LTE traditional users and proposed to reserve the idle radio resources in LTE for vehicular safety services. Additionally, the weighted-fair-queuing (WFQ) algorithm was proposed to schedule beacons for safety services using the LTE reserved resources. [PERSON] et al. [41] investigated the budget-constrained and delay-bounded roadside units' (RSUs) placement problem in VANETs and formulated the budget constrained and delay-bounded placement (BCDP) problem to the budgeted maximum coverage problem, which was proven NP-hard. Heuristic algorithms were proposed to solve the problem, to reduce the RSU installation cost and provide a wide coverage for data dissemination. [PERSON] et al. [42] investigated the data dissemination process in a cooperative communication mode. They fully utilized the capacity of VANETs' mobility and then developed an analytical framework to model the capacity achieved by the vehicles of interest (VoIs) in VANET. [PERSON] et al. [43] proposed an adaptive quality of service (QoS)-based routing for VANETs (AQRV), in which the intersections were adaptively chosen, through which data packets pass to reach the destination. To achieve the QoS constraints, the routing selection issue was mathematically formulated as a constrained optimization problem, and an ant colony optimization (ACO)-based algorithm was proposed to solve this problem. However, few of the schemes for data dissemination consider controlling the number of message copies in the network.