Experiments

The sources necessary for simulation and evaluation of the results are available here.

We have simulated several different scenarios (on different scales and using several randomly generated variants). Two of them are elaborated below. The objective of the scenarios is to illustrate the performance gain by employing the communication boundary, which limits data sharing strictly to the regions outlined by the communication boundary. All scenarios are based on monitoring how fast FireFighter (FF) Leaders get notified about FF Members of their team that get into a dangerous situation (teams are deployed in dedicated spatial areas).

The technical parameters common in all simulations are:

Simulation run is 60 seconds
Every member gets into danger between 15s and 30s (and stays there)
Areas are squares of fixed area of 100 by 100 meters
There are 2 Leaders per team in each area
Nodes are evenly distributed (on average 1 node per each 20x20m region)
Wireless communication range is 25 meters (emulating the indoor condition of the scenarios)
The size of a single replica is 128 bytes = 1 packet (including both the application data and metadata such as hop count, sender, version number, etc.)
Ethernet is set to 10Mbps bandwidth and 100ms latency
Knowledge publishing period is 2 seconds
Ethernet is available to 25% of nodes (randomly selected)
Max random broadcast (MANET) gossip delay is 1s
Constant direct (Ethernet) gossip delay is 400ms
Number of peers selected for direct (Ethernet) gossip step is 2

Case 1

The scenario consists of several deployed firefighter teams that partially overlap in terms of the radio signal coverage (on average 20 nodes per team, 2 leaders per team). Each team uses the other teams’ members as relays for knowledge dissemination in the overlapping areas to ensure the necessary wireless coverage.

Results

Time for discovering a team Member in danger by a corresponding Leader.

Number of replicas disseminated within the whole system.

Number of unnecessary disseminations that were prevented due to communication boundary (when enabled).

Raw data

Simulation inputs	inputs.zip
Raw results	results.zip

Case 2

The scenario includes a single FireFighter (FF) team deployed over two areas interconnected via Ethernet (25 FFs per area, 2 leaders per area). The areas are surrounded by external components. The boundary condition of FF ensemble prevents FF knowledge leaving the two buildings. The boundary condition of the surrounding components prevents the data from entering the two buildings (i.e., the two boundary conditions are complementary).

Results

Raw data

Simulation inputs	inputs.zip
Raw results	results.zip