# FOXS-GSC--Fast Offset Xpath Service with HexagonS Communication
## 2 Related Work  
Generally, many ITS applications use Vehicular Ad Hoc Networks to send messages from a source (vehicle, RSU) to all vehicles located inside a geographic region [19]. Such activity is known as data dissemination. Two important challenges in developing a data discrimination solution are the broadcast storm and the intermittently connected network problems. The broadcast storm problem happens when many nearby vehicles try to communicate at the same time, drastically increasing message collision [20; 21]. The intermittently connected network problem happens when the number of vehicles is reduced (e.g., daybreak, holidays, and rural areas), requiring the data messages to be disseminated using direct multi-hop communication [22; 23]. In addition to these challenges, each application has specific requirements which demand different strategies to support data dissemination. Many data dissemination solutions have been proposed to address these challenges [19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30]. [PERSON] et al. [20] presented Distributed Vehicular Broadcast (DV-CAST), a data dissemination solution that proposes solving the broadcast storm and network partition problems. DV-CAST uses periodic beacon messages to build a local topology (one-hop neighbors) used to rebroadcast a message to the vehicle moving in the same direction as the destination. DV-CAST performs data dissemination in both sparse and dense networks, focusing only on highway topologies. In a dense network, the receiver applies the broadcast suppression algorithm and uses the store-carry-forward algorithm sparsely. However, the performance of DV-CAST depends on the well-tuned beacon frequency. UV-CAST (urban vehicular broad-cast protocol) [22] was proposed to perform data dissemination in different traffic conditions. UV-CAST uses broadcast suppression or store-carry-forward depending on the vehicle's relative position with respect to the sender. If the vehicle is on the edge of a connected component, UV-CAST infers that it has a higher probability of meeting new neighbors. Thus, the received message is stored until rendezvous with a new neighbor. However, if the vehicle is not a border vehicle then the broadcast suppression algorithm can rebroadcast the message. [PERSON] et al. [24] proposed the Data Dissemination Protocol in Vehicular Networks (DRIVE), a new solution to perform data dissemination in VANETs, considering dense and sparse network scenarios. DRIVE relies exclusively on local one-hop neighbor information to deliver messages in these scenarios. It uses the predictability of vehicle mobility and the distance to the transmitter to create a preference zone in order to set the delay on the message retransmission. Furthermore, the solution employs implicit acknowledgments to guarantee robustness in message delivery under sparse scenarios. However, the number of transmissions is increased by the need for acknowledgment messages. [PERSON] et al. [26] proposed a data dissemination protocol called Autonomic Data Dissemination in Highway for VANETs (ADDHV), providing more excellent coverage and low delay in data dissemination independently of the regional traffic conditions. The authors created two mechanisms to mitigate the broadcast storm and network partition problems. For the broadcast storm problem, a mechanism based on [24] was used, which defined regions called sweet spots inside of which vehicles have a higher priority to rebroadcast messages and a lower delay. For the network partition problem, an autonomic computing technique was implemented to decide whether the vehicle should disseminate a packet or not. This choice was based on a propagation efficiency concept and the geographic localization of vehicles. However, ADDHV can introduce additional network overhead because of the store-carry-forward mechanism applied in the solution. [PERSON] et al. [28] developed the Context-Aware Routing pROtocol (CARRO), which explores the geographic context knowledge for data dissemination VANETs on urban and highway scenery.