GSAF: Efficient and flexible geocasting for opportunistic networks

Abstract

Abstract-With the proliferation of smartphones and their advanced connectivity capabilities, opportunistic networks have gained a lot of traction during the past years; they are suitable for increasing network capacity and sharing ephemeral, localised content. They can also offload traffic from cellular networks to device-to-device ones, when cellular networks are heavily stressed. Opportunistic networks can play a crucial role in communication scenarios where the network infrastructure is inaccessible due to natural disasters, large-scale terrorist attacks or government censorship. Geocasting, where messages are destined to specific locations (casts) instead of explicitly identified devices, has a large potential in real world opportunistic networks, however it has attracted little attention in the context of opportunistic networking.In this paper we propose Geocasting Spray And Flood (GSAF), a simple but efficient and flexible geocasting protocol for opportunistic, delay-tolerant networks. GSAF follows a simple but elegant and flexible approach where messages take random walks towards the destination cast. Messages that follow directions away from the cast are extinct when the device buffer gets full, freeing space for new messages to be delivered. In GSAF, casts do not have to be pre-defined; instead users can route messages to arbitrarily defined casts. Our extensive evaluation shows that GSAF is efficient, in terms of message delivery ratio and latency as well as network overhead.

Evaluating Forwarding Protocols in Opportunistic Networks: Trends, Advances, Challenges and Best Practices

“…GSAF [50] 2016 Destination dependent identifier is used to spray messages to forwarders. After the message is in the locality of the destination, it is flooded to all neighbors.…”

“…It is also very useful with hybrid models, where for example some nodes move similar to vehicles and others similar to pedestrians. This has been for example applied in GSAF [50], kRop [69] and MLProph [71] where bus movement is used for vehicles and pedestrians use shortest path map based movement. Figure 7 summarizes the used mobility models in the here explored studies.…”

Efficient Geocasting in Opportunistic Networks

“…Note that the initial number of tickets T is set to 5 for both GSAF and DA-GSAF protocols, in this scenario. In [29] we presented the results of simulations of GSAF, in comparison to GeoEpidemic, in the city centre of Helsinki when all user mobility was based on ONE's random mobility model.…”

“…Due to space limitations and in order to provide more insights on how all studied protocols perform, we will not reproduce here the results presented in [29]. In this scenario, we evaluate the performance of GSAF, DA-GSAF, GeoEpidemic and EVR.…”

The Impact of Message Replication on the Performance of Opportunistic Networks for Sensed Data Collection

“…Hence, a message may never be delivered if only one copy exists in the network, as its custodian may miss important encounter opportunities. Also, the wireless communication interface on handheld user devices could be shared among different applications, including other OppNet applications such as content dissemination [64] and location-targeted services [65]. With single-copy replication, the only existing message copy would thereby compete with these other applications and messages whenever a data transmission opportunity arises.…”