824 research outputs found
Network-Assisted Resource Allocation with Quality and Conflict Constraints for V2V Communications
The 3rd Generation Partnership Project (3GPP) has recently established in
Rel. 14 a network-assisted resource allocation scheme for vehicular broadcast
communications. Such novel paradigm is known as vehicle--to--vehicle (V2V)
\textit{mode-3} and consists in eNodeBs engaging only in the distribution of
sidelink subchannels among vehicles in coverage. Thereupon, without further
intervention of the former, vehicles will broadcast their respective signals
directly to their counterparts. Because the allotment of subchannels takes
place intermittently to reduce signaling, it must primarily be conflict-free in
order not to jeopardize the reception of signals. We have identified four
pivotal types of allocation requirements that must be guaranteed: one quality
of service (QoS) requirement and three conflict conditions which must be
precluded in order to preserve reception reliability. The underlying problem is
formulated as a maximization of the system sum-capacity with four types of
constraints that must be enforced. In addition, we propose a three-stage
suboptimal approach that is cast as multiple independent knapsack problems
(MIKPs). We compare the two approaches through simulations and show that the
latter formulation can attain acceptable performance at lesser complexity
Hybrid-Vehfog: A Robust Approach for Reliable Dissemination of Critical Messages in Connected Vehicles
Vehicular Ad-hoc Networks (VANET) enable efficient communication between
vehicles with the aim of improving road safety. However, the growing number of
vehicles in dense regions and obstacle shadowing regions like Manhattan and
other downtown areas leads to frequent disconnection problems resulting in
disrupted radio wave propagation between vehicles. To address this issue and to
transmit critical messages between vehicles and drones deployed from service
vehicles to overcome road incidents and obstacles, we proposed a hybrid
technique based on fog computing called Hybrid-Vehfog to disseminate messages
in obstacle shadowing regions, and multi-hop technique to disseminate messages
in non-obstacle shadowing regions. Our proposed algorithm dynamically adapts to
changes in an environment and benefits in efficiency with robust drone
deployment capability as needed. Performance of Hybrid-Vehfog is carried out in
Network Simulator (NS-2) and Simulation of Urban Mobility (SUMO) simulators.
The results showed that Hybrid-Vehfog outperformed Cloud-assisted Message
Downlink Dissemination Scheme (CMDS), Cross-Layer Broadcast Protocol (CLBP),
PEer-to-Peer protocol for Allocated REsource (PrEPARE), Fog-Named Data
Networking (NDN) with mobility, and flooding schemes at all vehicle densities
and simulation times
- …