A study on effective algorithm for selecting PVA nodes in VANETs

In Vehicular Ad-hoc NETwork (VANET), network performances represented by connectivity and/or throughput are much influenced by mobility patterns and densities, of vehicles. In order to improve network performance even if the density of vehicles is low, A method named Parked Vehicle Assistance (PVA) has been proposed[1]. PVA method improves network densities by introducing vehicle which is parking at a roadside, to the VANET, as a relay node of the communications (PVA node). The literature [1] reported that the performances of VANETs can be improved even if the number of PVA nodes is few. However, these performance evaluations have been conducted under the situation that the candidate nodes of PVA were randomly selected, from entire the simulation field, that is, in these evaluations PVA nodes were selected without strategies. Under the such condition, a number of needless candidate nodes will be selected as PVA nodes, and it increases needless traffic on VANETs. Then, in this paper, in order to improve VANET performance with smaller number of PVA nodes, we propose an algorithm for selecting PVA nodes in VANETs, and clarify the proposed algorithm can improve VANET performance effectively by computer simulations.