def test_count_timeslots_parallel():
"""Tests correct counting behaviour with parallel connections"""
infra = InfrastructureNetwork()
# One source, one sink, two intermediates
nsource = infra.add_source(
pos=(0, 0), transmit_power_dbm=30, name="nsource"
)
ninterm1 = infra.add_intermediate(
pos=(1, 2), transmit_power_dbm=30, name="ninterm1"
)
ninterm2 = infra.add_intermediate(
pos=(1, -2), transmit_power_dbm=30, name="ninterm2"
)
nsink = infra.set_sink(pos=(2, 0), transmit_power_dbm=30, name="nsink")
overlay = OverlayNetwork()
esource = ENode(overlay.add_source(name="bsource"), nsource)
einterm1 = ENode(overlay.add_intermediate(name="binterm1"), ninterm1)
einterm2 = ENode(overlay.add_intermediate(name="binterm2"), ninterm2)
esink = ENode(overlay.set_sink(name="bsink"), nsink)
# fork
overlay.add_link(esource.block, einterm1.block)
overlay.add_link(esource.block, einterm2.block)
overlay.add_link(einterm1.block, esink.block)
overlay.add_link(einterm2.block, esink.block)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(esource.block, esource.node)]
)
assert not embedding.is_complete()
assert embedding.used_timeslots == 0
assert embedding.take_action(esource, einterm1, 0)
assert embedding.take_action(esource, einterm2, 0)
assert not embedding.is_complete()
assert embedding.used_timeslots == 1
assert embedding.take_action(einterm1, esink, 1)
assert not embedding.is_complete()
assert embedding.used_timeslots == 2
assert embedding.take_action(einterm2, esink, 2)
assert embedding.is_complete()
assert embedding.used_timeslots == 3
def test_count_timeslots_loop():
"""Tests reasonable counting behaviour with loops"""
infra = InfrastructureNetwork()
# One source, one sink, two intermediates
nsource = infra.add_source(pos=(0, 0), transmit_power_dbm=30, name="nso")
ninterm1 = infra.add_intermediate(
pos=(2, 1), transmit_power_dbm=5, name="ni1"
)
ninterm2 = infra.add_intermediate(
pos=(0, -1), transmit_power_dbm=5, name="ni2"
)
nsink = infra.set_sink(pos=(2, 0), transmit_power_dbm=30, name="nsi")
overlay = OverlayNetwork()
esource = ENode(overlay.add_source(name="bso"), nsource)
einterm1 = ENode(overlay.add_intermediate(name="bi1"), ninterm1)
einterm2 = ENode(overlay.add_intermediate(name="bi2"), ninterm2)
esink = ENode(overlay.set_sink(name="bsi"), nsink)
overlay.add_link(esource.block, einterm1.block)
overlay.add_link(einterm1.block, esink.block)
overlay.add_link(esink.block, einterm2.block)
overlay.add_link(einterm2.block, esource.block)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(esource.block, esource.node)]
)
assert not embedding.is_complete()
assert embedding.used_timeslots == 0
assert embedding.take_action(esource, einterm1, 0)
assert not embedding.is_complete()
assert embedding.used_timeslots == 1
assert embedding.take_action(einterm1, esink, 1)
assert not embedding.is_complete()
assert embedding.used_timeslots == 2
assert embedding.take_action(esink, einterm2, 2)
assert not embedding.is_complete()
assert embedding.used_timeslots == 3
assert embedding.take_action(einterm2, esource, 1)
assert embedding.is_complete()
assert embedding.used_timeslots == 3
def test_all_viable_options_offered():
"""
Tests that all manually verified options are offered in a concrete
example.
"""
infra = InfrastructureNetwork()
# Two sources, one sink, one intermediate, one relay
# Enough transmit power so that it doesn't need to be taken into account
nso1 = infra.add_source(
pos=(0, 0),
# transmit power should not block anything in this example
transmit_power_dbm=100,
name="nso1",
)
nso2 = infra.add_source(pos=(1, 0), transmit_power_dbm=100, name="nso2")
_nrelay = infra.add_intermediate(
pos=(0, 1), transmit_power_dbm=100, name="nr"
)
_ninterm = infra.add_intermediate(
pos=(2, 0), transmit_power_dbm=100, name="ni"
)
_nsink = infra.set_sink(pos=(1, 1), transmit_power_dbm=100, name="nsi")
overlay = OverlayNetwork()
bso1 = overlay.add_source(name="bso1")
bso2 = overlay.add_source(name="bso2")
bsi = overlay.set_sink(name="bsi")
bin_ = overlay.add_intermediate(name="bin")
eso1 = ENode(bso1, nso1)
eso2 = ENode(bso2, nso2)
# source1 connects to the sink over the intermediate source2
# connects both to the sink and to source1.
overlay.add_link(bso1, bin_)
overlay.add_link(bin_, bsi)
overlay.add_link(bso2, bsi)
overlay.add_link(bso2, bso1)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(bso1, eso1.node), (bso2, eso2.node)]
)
# source1 can connect to the intermediate, which could be embedded
# in any node (5). It could also connect to any other node as a
# relay (4) -> 9. source2 can connect to the sink (1) or the other
# source (1). It could also connect to any other node as a relay for
# either of its two links (2 * 3) -> 8 No timeslot is used yet, so
# there is just one timeslot option.
assert len(embedding.possibilities()) == 9 + 8
def test_block_capacity():
"""Tests that per-node capacity is respected for each timeslot"""
infra = InfrastructureNetwork()
nso = infra.add_source(pos=(0, 0), transmit_power_dbm=30, name="nso")
nin1 = infra.add_intermediate(
pos=(-1, 1), transmit_power_dbm=30, capacity=42, name="nin1"
)
nin2 = infra.add_intermediate(
pos=(1, 1), transmit_power_dbm=30, capacity=5, name="nin2"
)
_nsi = infra.set_sink(pos=(0, 1), transmit_power_dbm=30, name="nsi")
overlay = OverlayNetwork()
# ignore sinr constraints -> 0 datarate requirements
bso = overlay.add_source(name="bso", datarate=0)
bin1 = overlay.add_intermediate(requirement=40, name="bin1", datarate=0)
bin2 = overlay.add_intermediate(requirement=5, name="bin2", datarate=0)
bsi = overlay.set_sink(name="bsi", datarate=0)
overlay.add_link(bso, bin1)
overlay.add_link(bso, bin2)
overlay.add_link(bin1, bsi)
overlay.add_link(bin2, bsi)
embedding = PartialEmbedding(infra, overlay, source_mapping=[(bso, nso)])
eso = ENode(bso, nso)
possibilities = embedding.possibilities()
# bin1 can be embedded in nin1, because 42>=40
assert (eso, ENode(bin1, nin1), 0) in possibilities
# but not in nin2 because it does not have enough capacity
assert (eso, ENode(bin1, nin2), 0) not in possibilities
# bin2 has less requirements and can be embedded in either one
assert (eso, ENode(bin2, nin1), 0) in possibilities
assert (eso, ENode(bin2, nin2), 0) in possibilities
# embed bin1 in nin1
assert embedding.take_action(ENode(bso, nso), ENode(bin1, nin1), 0)
possibilities = embedding.possibilities()
# pylint:disable=protected-access
# The easiest way to test this, not too hard to adjust when
# internals change.
assert embedding._capacity_used[nin1] == 40
# which means bin2 can no longer be embedded in it
assert (eso, ENode(bin2, nin1), 0) not in possibilities
# while it can still be embedded in nin2
assert (eso, ENode(bin2, nin2), 0) in possibilities
def _build_example():
# for quick testing
infra = InfrastructureNetwork()
n1 = infra.add_source(pos=(0, 3),
transmit_power_dbm=14,
capacity=5,
name="N1")
n2 = infra.add_source(pos=(0, 1),
transmit_power_dbm=8,
capacity=8,
name="N2")
n3 = infra.add_intermediate(pos=(2, 2),
transmit_power_dbm=32,
capacity=20,
name="N3")
n4 = infra.set_sink(pos=(3, 0),
transmit_power_dbm=10,
capacity=10,
name="N4")
n5 = infra.add_intermediate(pos=(1, 2),
transmit_power_dbm=20,
capacity=42,
name="N5")
overlay = OverlayNetwork()
b1 = overlay.add_source(requirement=5, name="B1")
b2 = overlay.add_source(requirement=5, name="B2")
b3 = overlay.add_intermediate(requirement=5, name="B3")
b4 = overlay.set_sink(requirement=5, name="B4")
overlay.add_link(b1, b3)
overlay.add_link(b2, b3)
overlay.add_link(b3, b4)
overlay.add_link(b2, b4)
embedding = PartialEmbedding(infra,
overlay,
source_mapping=[(b1, n1), (b2, n2)])
assert embedding.take_action(ENode(b1, n1), ENode(None, n5), 0)
assert embedding.take_action(ENode(None, n5, ENode(b1, n1)), ENode(b3, n3),
1)
assert embedding.take_action(ENode(b2, n2), ENode(None, n5), 2)
assert embedding.take_action(ENode(None, n5, ENode(b2, n2)), ENode(b3, n3),
3)
assert embedding.take_action(ENode(b2, n2), ENode(b4, n4), 2)
assert embedding.take_action(ENode(b3, n3), ENode(b4, n4), 4)
return embedding
def test_completion_detection():
"""
Tests that the completeness of an embedding is accurately detected
in a simple example.
"""
infra = InfrastructureNetwork()
# One source, one sink, one relay.
# Enough transmit power so that it doesn't need to be taken into account
nsource = infra.add_source(
pos=(0, 0),
# transmit power should not block anything in this example
transmit_power_dbm=100,
)
_nrelay = infra.add_intermediate(pos=(0, 1), transmit_power_dbm=100)
nsink = infra.set_sink(pos=(1, 1), transmit_power_dbm=100)
overlay = OverlayNetwork()
esource = ENode(overlay.add_source(), nsource)
esink = ENode(overlay.set_sink(), nsink)
overlay.add_link(esource.block, esink.block)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(esource.block, esource.node)]
)
assert not embedding.is_complete()
embedding.take_action(esource, esink, 0)
assert embedding.is_complete()
def test_non_broadcast_parallel_communications_impossible():
"""Tests that non-broadcast parallel communications *do* affect the
SINR."""
infra = InfrastructureNetwork()
nso1 = infra.add_source(pos=(1, 0), transmit_power_dbm=30, name="nso1")
nso2 = infra.add_source(pos=(-1, 0), transmit_power_dbm=30, name="nso2")
nin = infra.add_intermediate(pos=(1, 0), transmit_power_dbm=30, name="nin")
nsi = infra.set_sink(pos=(2, 0), transmit_power_dbm=30, name="nsi")
overlay = OverlayNetwork()
bso1 = overlay.add_source(name="bso1")
bso2 = overlay.add_source(name="bso2")
bsi = overlay.set_sink(name="bsi")
overlay.add_link(bso1, bsi)
overlay.add_link(bso2, bsi)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(bso1, nso1), (bso2, nso2)]
)
# both sources use nin as a relay
eso1 = ENode(bso1, nso1)
eso2 = ENode(bso2, nso2)
esi = ENode(bsi, nsi)
ein1 = ENode(bso1, nin, bsi)
ein2 = ENode(bso2, nin, bsi)
assert embedding.take_action(eso1, ein1, 0)
assert embedding.take_action(eso2, ein2, 1)
assert embedding.take_action(ein1, esi, 2)
assert (ein2, esi, 2) not in embedding.possibilities()
def test_relay_circles_impossible():
"""Tests that each relay node can be taken at most once in a
path"""
infra = InfrastructureNetwork()
N2 = infra.add_source(name="N2", pos=(4.8, 5.7), transmit_power_dbm=29.7)
N4 = infra.add_intermediate(
name="N4", pos=(4.7, 8.8), transmit_power_dbm=13.4
)
_N1 = infra.set_sink(name="N1", pos=(7.7, 5.2), transmit_power_dbm=22.9)
overlay = OverlayNetwork()
B2 = overlay.add_source(name="B2", requirement=0, datarate=0)
_B5 = overlay.add_intermediate(name="B5", requirement=0, datarate=0)
B4 = overlay.add_intermediate(name="B4", requirement=0, datarate=0)
B1 = overlay.set_sink(name="B1", requirement=0, datarate=0)
overlay.add_link(B2, B4)
overlay.add_link(B4, B1)
embedding = PartialEmbedding(infra, overlay, source_mapping=[(B2, N2)])
eso = ENode(B2, N2)
ein1 = ENode(B2, N4, B4)
ein2 = ENode(B2, N2, B4)
assert embedding.take_action(eso, ein1, 0)
# n2 was already visited, circle
assert not embedding.take_action(ein1, ein2, 1)
def test_link_edges_cannot_be_embedded_twice():
"""Tests that edges completing a link that is already embedded are
removed or not even added when creating a new timestep"""
infra = InfrastructureNetwork()
nso = infra.add_source(pos=(0, 0), transmit_power_dbm=30, name="nso")
nsi = infra.set_sink(pos=(2, 0), transmit_power_dbm=30, name="nsi")
_nint = infra.add_intermediate(
pos=(1, -1), transmit_power_dbm=30, name="nint"
)
overlay = OverlayNetwork()
bso = overlay.add_source(name="bso")
bsi = overlay.set_sink(name="bsi")
bint = overlay.add_intermediate(name="bint")
overlay.add_link(bso, bsi)
overlay.add_link(bso, bint)
overlay.add_link(bint, bsi)
embedding = PartialEmbedding(infra, overlay, source_mapping=[(bso, nso)])
eso = ENode(bso, nso)
esi = ENode(bsi, nsi)
# now the link from source to sink is already embedded, only the one
# from source to intermediate should be left
assert embedding.take_action(eso, esi, 0)
# so embedding it again should not be possible
assert not embedding.take_action(ENode(bso, nso), ENode(bsi, nsi), 1)
def test_block_embedding_is_unique():
"""Tests that other embedding options are removed once one of them
is chosen"""
infra = InfrastructureNetwork()
nso1 = infra.add_source(pos=(0, 0), transmit_power_dbm=26, name="nso1")
nso2 = infra.add_source(pos=(2, 0), transmit_power_dbm=26, name="nso2")
_nsi = infra.set_sink(pos=(0, 1), transmit_power_dbm=16, name="nsi")
n1 = infra.add_intermediate(pos=(1, 0), transmit_power_dbm=16, name="n1")
_n2 = infra.add_intermediate(pos=(1, 1), transmit_power_dbm=16, name="n2")
overlay = OverlayNetwork()
bso1 = overlay.add_source(name="bso1")
bso2 = overlay.add_source(name="bso2")
binterm = overlay.add_intermediate(name="binterm")
bsi = overlay.set_sink(name="bsi")
overlay.add_link(bso1, binterm)
# there are multiple in-edges to binterm, which could lead to
# multiple different embeddings
overlay.add_link(bso2, binterm)
overlay.add_link(binterm, bsi)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(bso1, nso1), (bso2, nso2)]
)
eso1 = ENode(bso1, nso1)
def embeddings_for_block(block):
count = 0
for node in embedding.graph.nodes():
if node.block == block:
count += 1
return count
# could embed binterm in multiple blocks
assert embeddings_for_block(binterm) > 1
# decide for one embedding
assert embedding.take_action(eso1, ENode(binterm, n1), 0)
# other options are removed
assert embeddings_for_block(binterm) == 1
def parse_infra(
nodes_file,
sink_source_mapping,
positions_file,
source_seed,
transmit_power_dbm,
):
"""Reads an infrastructure definition in MARVELO format from csvs"""
# read the files
names = []
capacities = []
positions = []
for (_id, name, capacity) in csv_to_list(nodes_file):
names.append(name)
capacities.append(float(capacity))
for csvline in csv_to_list(positions_file, sep=";"):
positions.append([float(pos) for pos in csvline[1:]])
# the positions are saved in a weird format, probably a mistake when
# saving
positions = np.transpose(positions)
specs = list(zip(names, capacities, positions))
(sink_idx, source_idx) = sink_source_mapping[(source_seed, len(specs))]
if source_idx == sink_idx:
return None
# make sure source is always first, sink always last
specs[0], specs[source_idx] = specs[source_idx], specs[0]
specs[-1], specs[sink_idx] = specs[sink_idx], specs[-1]
# construct the infrastructure from the gathered info
infra = InfrastructureNetwork(bandwidth=1, noise_floor_dbm=-30)
for (name, capacity, pos) in specs[:1]:
infra.add_source(pos, transmit_power_dbm, capacity, name)
for (name, capacity, pos) in specs[1:-1]:
infra.add_intermediate(pos, transmit_power_dbm, capacity, name)
for (name, capacity, pos) in specs[-1:]:
infra.set_sink(pos, transmit_power_dbm, capacity, name)
return infra
def random_infrastructure(self, num_sources: int, rand):
"""Generates a randomized infrastructure"""
assert num_sources > 0
infra = InfrastructureNetwork()
rand_node_args = lambda: {
"pos": self.pos_dist(rand),
"transmit_power_dbm": self.power_dist(rand),
"capacity": self.capacity_dist(rand),
}
infra.set_sink(**rand_node_args())
for _ in range(num_sources):
infra.add_source(**rand_node_args())
for _ in range(self.interm_nodes_dist(rand)):
infra.add_intermediate(**rand_node_args())
return infra
def test_unnecessary_links_removed_in_other_timeslots():
"""
Tests that links in other timeslots are removed if they are embedded
in one timeslot.
"""
infra = InfrastructureNetwork()
nfaraway_1 = infra.add_source(
pos=(999999998, 99999999), transmit_power_dbm=5, name="nfaraway_1"
)
nfaraway_2 = infra.add_intermediate(
pos=(999999999, 99999999), transmit_power_dbm=5, name="nfaraway_2"
)
nsi = infra.set_sink(pos=(9, 5), transmit_power_dbm=12, name="nsi")
nso = infra.add_source(pos=(8, 3), transmit_power_dbm=3, name="nso")
overlay = OverlayNetwork()
bsi = overlay.set_sink(name="bsi")
bso = overlay.add_source(name="bso")
bfaraway_1 = overlay.add_source(name="bfaraway_1")
bfaraway_2 = overlay.add_intermediate(name="bfaraway_2", datarate=0)
overlay.add_link(bso, bsi)
overlay.add_link(bfaraway_1, bfaraway_2)
# just to make it correct
overlay.add_link(bfaraway_2, bsi)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(bso, nso), (bfaraway_1, nfaraway_1)]
)
esi = ENode(bsi, nsi)
eso = ENode(bso, nso)
efaraway_1 = ENode(bfaraway_1, nfaraway_1)
efaraway_2 = ENode(bfaraway_2, nfaraway_2)
# make sure a second timeslot is created
assert embedding.take_action(efaraway_1, efaraway_2, 0)
# make sure embedding is possible in ts1
assert (eso, esi, 1) in embedding.possibilities()
# embed the link in ts 0
assert embedding.take_action(eso, esi, 0)
# now no embedding in another timeslot should be possible anymore
possible_outlinks_from_eso = [
pos for pos in embedding.possibilities() if pos[0] == eso
]
assert len(possible_outlinks_from_eso) == 0
def test_broadcast_possible():
"""Tests that broadcast is possible despite SINR constraints"""
infra = InfrastructureNetwork()
# One source, one sink, one intermediate
nsource = infra.add_source(pos=(0, 0), transmit_power_dbm=30)
ninterm = infra.add_intermediate(pos=(1, 2), transmit_power_dbm=30)
nsink = infra.set_sink(pos=(2, 0), transmit_power_dbm=30)
overlay = OverlayNetwork()
esource = ENode(overlay.add_source(), nsource)
einterm = ENode(overlay.add_intermediate(), ninterm)
esink = ENode(overlay.set_sink(), nsink)
# fork
overlay.add_link(esource.block, einterm.block)
overlay.add_link(esource.block, esink.block)
# make complete
overlay.add_link(einterm.block, esink.block)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(esource.block, esource.node)]
)
# Broadcast from source to sink and intermediate
sinr_before = embedding.known_sinr(esource.node, esink.node, timeslot=0)
assert embedding.take_action(esource, esink, 0)
# Easiest way to test this, easy to change if internals change.
# pylint: disable=protected-access
power_at_sink = embedding.infra.power_at_node(
esink.node, frozenset(embedding._nodes_sending_in[0])
)
assert embedding.take_action(esource, einterm, 0)
# Make sure the broadcasting isn't counted twice
new_power = embedding.infra.power_at_node(
esink.node, frozenset(embedding._nodes_sending_in[0])
)
assert new_power == power_at_sink
# Make sure the broadcasts do not interfere with each other
assert sinr_before == embedding.known_sinr(
esource.node, esink.node, timeslot=0
)
def test_outlinks_limited():
"""
Tests that the number of possible outlinks is limited by the number
of outlinks to embed for that block.
"""
infra = InfrastructureNetwork()
nsource = infra.add_source(pos=(0, 0), transmit_power_dbm=1, name="nso")
nrelay = infra.add_intermediate(
pos=(1, 0), transmit_power_dbm=1, name="nr"
)
# The sink is way out of reach, embedding is not possible
_nsink = infra.set_sink(pos=(1, 1), transmit_power_dbm=1, name="nsi")
overlay = OverlayNetwork()
bsource = overlay.add_source(name="bso")
bsink = overlay.set_sink(name="bsi")
esource = ENode(bsource, nsource)
overlay.add_link(bsource, bsink)
embedding = PartialEmbedding(
infra, overlay, source_mapping=[(esource.block, esource.node)]
)
erelay = ENode(bsource, nrelay, bsink)
assert embedding.take_action(esource, erelay, 0)
possibilities_from_source = [
(source, target, timeslot)
for (source, target, timeslot) in embedding.possibilities()
if source == esource
]
# the source block has one outgoing edge, one outlink is already
# embedded (although the link is not embedded completely)
assert len(possibilities_from_source) == 0
possibilities_from_relay = [
(source, target, timeslot)
for (source, target, timeslot) in embedding.possibilities()
if source == erelay
]
# yet the link can be continued from the relay
assert len(possibilities_from_relay) > 0
def test_half_duplex():
"""Tests that a node cannot send and receive at the same time"""
infra = InfrastructureNetwork()
nso = infra.add_source(name="nso", pos=(0, 0), transmit_power_dbm=30)
ni = infra.add_intermediate(name="ni", pos=(1, 0), transmit_power_dbm=30)
nsi = infra.set_sink(name="nsi", pos=(2, 0), transmit_power_dbm=30)
overlay = OverlayNetwork()
# links have no datarate requirements, so SINR concerns don't apply
bso = overlay.add_source(name="bso", datarate=0)
bsi = overlay.set_sink(name="bsi", datarate=0)
overlay.add_link(bso, bsi)
embedding = PartialEmbedding(infra, overlay, source_mapping=[(bso, nso)])
eso = ENode(bso, nso)
esi = ENode(bsi, nsi)
ein = ENode(bso, ni, bsi)
print(embedding.possibilities())
assert embedding.take_action(eso, ein, 0)
assert not embedding.take_action(ein, esi, 0)
def test_same_connection_not_possible_twice():
"""Tests that the same connection cannot be taken twice"""
infra = InfrastructureNetwork()
N2 = infra.add_source(name="N2", pos=(2.3, 2.2), transmit_power_dbm=26.9)
N3 = infra.add_intermediate(name="N3", pos=(0, 4), transmit_power_dbm=11)
_N1 = infra.set_sink(name="N1", pos=(9.4, 9.5), transmit_power_dbm=26.1)
overlay = OverlayNetwork()
B2 = overlay.add_source(name="B2")
B3 = overlay.add_intermediate(name="B3")
B1 = overlay.set_sink(name="B1")
overlay.add_link(B2, B1)
overlay.add_link(B2, B3)
overlay.add_link(B3, B1)
embedding = PartialEmbedding(infra, overlay, source_mapping=[(B2, N2)])
eso = ENode(B2, N2)
ein = ENode(B2, N3, B1)
assert embedding.take_action(eso, ein, 0)
# this connection has already been taken
assert not embedding.take_action(eso, ein, 1)
def test_manually_verified_sinr():
"""
Tests that the SINR calculation agrees with a manually verified
example.
"""
infra = InfrastructureNetwork(noise_floor_dbm=15)
# 2 sources, 2 intermediaries, 1 sink
n_source1 = infra.add_source(pos=(0, 0), transmit_power_dbm=30)
n_interm1 = infra.add_intermediate(pos=(1, 0), transmit_power_dbm=30)
n_source2 = infra.add_source(pos=(0, 2), transmit_power_dbm=30)
n_interm2 = infra.add_intermediate(pos=(1, 2), transmit_power_dbm=30)
n_sink = infra.set_sink(pos=(3, 1), transmit_power_dbm=0)
overlay = OverlayNetwork()
b_source1 = overlay.add_source()
b_interm1 = overlay.add_intermediate()
b_source2 = overlay.add_source()
b_interm2 = overlay.add_intermediate()
b_sink = overlay.set_sink()
overlay.add_link(b_source1, b_interm1)
overlay.add_link(b_source2, b_interm2)
# just to make the embedding complete
overlay.add_link(b_interm1, b_sink)
overlay.add_link(b_interm2, b_sink)
embedding = PartialEmbedding(
infra,
overlay,
source_mapping=[(b_source1, n_source1), (b_source2, n_source2)],
)
# this doesn't actually do anything, just makes the next step more
# convenient
e_source1 = ENode(b_source1, n_source1)
e_source2 = ENode(b_source2, n_source2)
e_interm1 = ENode(b_interm1, n_interm1)
e_interm2 = ENode(b_interm2, n_interm2)
e_sink = ENode(b_sink, n_sink)
# Here is the important part: Two signals in parallel
embedding.take_action(e_source1, e_interm1, 0)
embedding.take_action(e_source2, e_interm2, 0)
# We don't really care what is going on in other timeslots, this is
# just to make the embedding valid.
embedding.take_action(e_interm1, e_sink, 1)
embedding.take_action(e_interm2, e_sink, 2)
# Now we have a clean model to work with in timeslot 1: Two parallel
# communications, one signal and one noise.
# Let's calculate the SINR or signal1.
# source1 sends with 30dBm. There is a distance of 1m to interm1.
# According to the log path loss model with a loss exponent of 2
# (appropriate for a building), the signal will incur a loss of
# 2 * distance_decibel dBm
# Where distance_decibel is the distance in relation to 1m, i.e. 0
# in this case. That means there is *no loss*, at least according to
# the model.
# It follows that interm1 receives a signal of 30dBm. Now on to the
# received noise. source2 also sends with 30dBm and has a distance
# of sqrt(1^2 + 2^2) ~= 2.24m to interm1. According to the log path
# loss model:
# distance_decibel = 10 * lg(2.24) ~= 3.50
# => path_loss = 2 * 3.50 ~= 7 dBm
# So interm1 receives roughly 30 - 7 = 23 dBm of noise. Lets assume
# a base noise of 15dB. We have to add those two. Care must be taken
# here because of the logarithmic scale. Naive addition would result
# in multiplication of the actual power in watts. So we need to
# convert back to watts first, then add, then convert back:
# base_noise_milliwatts = 10^(1.5) ~= 31.62 mW
# com_noise_milliwatts = 10^(2.3) ~= 199.53 mW
# => total_noise = 31.62 + 199.53 = 231.15 mW
# The total noise is 231.15 mW, which equals
# 10*lg(231.15) ~= 23.64 dB
# That is way less than the naively calculated 16 + 15 = 31 dB.
# That means the SINR should be
# sinr = 30dBm - 23.64 = 6.36dB
# Here the subtraction actually *should* represent a division of the
# powers.
sinr = embedding.known_sinr(n_source1, n_interm1, 0)
assert sinr == approx(6.36, abs=0.1)