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[EN] Neighbor discovery represents a first step after the deployment of wireless ad hoc networks, since the nodes that form them are equipped with limited-range radio transceivers, and they typically do not know their neighbors. In this paper two randomized neighbor discovery approaches, called CDH and CDPRR, based on collision detection for static multi-hop wireless ad hoc networks, are presented. Castalia 3.2 simulator has been used to compare our proposed protocols against two protocols chosen from the literature and used as reference: the PRR, and the Hello protocol. For the experiments, we chose five metrics: the neighbor discovery time, the number of discovered neighbors, the energy consumption, the throughput and the number of discovered neighbors versus packets sent ratio. According to the results obtained through simulation, we can conclude that our randomized proposals outperform both Hello and PRR protocols in the presence of collisions regarding all five metrics, for both one-hop and multi-hop scenarios. As novelty compared to the reference protocols, both proposals allow nodes to discover all their neighbors with probability 1, they are based on collision detection and know when to terminate the neighbor discovery process. Furthermore, qualitative comparisons of the existing protocols and the proposals are available in this paper. Moreover, CDPRR presents better results in terms of time, energy consumption and number of discovered neighbors versus packets sent ratio. We found that both proposals achieve to operate under more realistic assumptions. Furthermore, CDH does not need to know the number of nodes in the network., This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.

In ad hoc wireless networks, the devices are equipped with limited range radio transceivers for communications. This type of networks does not have a communications infrastructure right after the deployment, and nodes do not know which other nodes are within their transmission range (neighbors). So, each node must discover its neighbors as a first step. In this paper we present two approaches to the neighbor discovery problem in static one-hop scenarios: TDMA-based (Time Division Multiple Access based) and Leader-based protocols. To assess the performance of these approaches we performed simulation experiments using the Castalia 3.2 simulator, comparing the proposed protocols against two protocols widely used in the literature as reference - the PRR (Probabilistic Round Robin) protocol and the Hello protocol - measuring two metrics: neighbor discovery time and number of discovered neighbors, for all the protocols tested. Results show that the leader-based and TDMA-based protocols outperform state-of-the-art solutions in the presence of collisions regarding both metrics, while finding that the TDMA-based protocol $(O(N^{2}))$ is slower than the leader-based approach $(O(N))$ . The TDMA-based proposal decreases time consumption at least at a factor of 6 in comparison with Hello protocol and a factor of 3 compared to PRR protocol. Furthermore, the leader-based protocol reduces the time consumption at least at a factor of $6N$ in comparison with Hello and a factor of $3N$ compared to PRR protocol.