5 files changed, 302 insertions, 0 deletions
diff --git a/osdf/optimizers/pciopt/solver/__init__.py b/osdf/optimizers/pciopt/solver/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/osdf/optimizers/pciopt/solver/__init__.py
diff --git a/osdf/optimizers/pciopt/solver/min_confusion.mzn b/osdf/optimizers/pciopt/solver/min_confusion.mzn
new file mode 100644
index 0000000..803f914
--- /dev/null
+++ b/osdf/optimizers/pciopt/solver/min_confusion.mzn
@@ -0,0 +1,95 @@
+% -------------------------------------------------------------------------
+%   Copyright (c) 2018 AT&T Intellectual Property
+%
+%   Licensed under the Apache License, Version 2.0 (the "License");
+%   you may not use this file except in compliance with the License.
+%   You may obtain a copy of the License at
+%
+%       http://www.apache.org/licenses/LICENSE-2.0
+%
+%   Unless required by applicable law or agreed to in writing, software
+%   distributed under the License is distributed on an "AS IS" BASIS,
+%   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%   See the License for the specific language governing permissions and
+%   limitations under the License.
+%
+% -------------------------------------------------------------------------
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Parameters and its assertions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Number of cells/radios.
+int: NUM_NODES;
+
+% Maximum number of Physical Cell Identifiers to be assigned to the nodes.
+int: NUM_PCIS;
+
+% Number of edges between neighbor nodes. There is a edge (i,j) if and only
+% if nodes i and j are neighbors, i.e., an user equipment (UE) can make
+% handoff between i and j. Such edges are used to avoid **CONFLICTS**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_CONFLICT_EDGES;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_CONFLICT_EDGES, 1..2] of int: CONFLICT_EDGES; 
+
+% Number of undirect neighbor pairs (j, k) such that both j and k are direct
+% neighbors of node i, i.e., (j, k) exits if and only if exists (i, j) and 
+% (i, k). Nodes (i, k) can generate "confunsions" in the network if they have
+% the same PCI. Such edges are used to avoid/minimize **CONFUSIONS**.
+int: NUM_CONFUSION_EDGES;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_CONFUSION_EDGES, 1..2] of int: CONFUSION_EDGES; 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **CONFLICTS**.
+constraint 
+forall(i in 1..NUM_CONFLICT_EDGES)(
+    pci[CONFLICT_EDGES[i, 1]] != pci[CONFLICT_EDGES[i, 2]]
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Total number of confusions.
+var int: total_confusions =
+    sum([bool2int(pci[CONFUSION_EDGES[i, 1]] == pci[CONFUSION_EDGES[i, 2]])
+         | i in 1..NUM_CONFUSION_EDGES]);
+
+% Minimize the total number of confusions.
+solve :: int_search(pci, smallest, indomain_min, complete)
+minimize total_confusions;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["PCI assigment"] ++ 
+["\nnode,pci"] ++
+[
+    "\n" ++ show(node) ++ "," ++ show(pci[node])
+| node in 0..NUM_NODES-1
+] ++
+
+["\n\nConfusions"] ++ 
+["\nTotal confusions: " ++ show(total_confusions)] ++
+["\nConfusion pairs"] ++
+[
+    "\n" ++ show(CONFUSION_EDGES[i, 1]) ++ "," ++ show(CONFUSION_EDGES[i, 2])
+| i in 1..NUM_CONFUSION_EDGES where 
+  fix(pci[CONFUSION_EDGES[i, 1]] == pci[CONFUSION_EDGES[i, 2]])
+]
diff --git a/osdf/optimizers/pciopt/solver/no_conflicts_no_confusion.mzn b/osdf/optimizers/pciopt/solver/no_conflicts_no_confusion.mzn
new file mode 100644
index 0000000..19fabb9
--- /dev/null
+++ b/osdf/optimizers/pciopt/solver/no_conflicts_no_confusion.mzn
@@ -0,0 +1,86 @@
+% -------------------------------------------------------------------------
+%   Copyright (c) 2018 AT&T Intellectual Property
+%
+%   Licensed under the Apache License, Version 2.0 (the "License");
+%   you may not use this file except in compliance with the License.
+%   You may obtain a copy of the License at
+%
+%       http://www.apache.org/licenses/LICENSE-2.0
+%
+%   Unless required by applicable law or agreed to in writing, software
+%   distributed under the License is distributed on an "AS IS" BASIS,
+%   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%   See the License for the specific language governing permissions and
+%   limitations under the License.
+%
+% -------------------------------------------------------------------------
+%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Parameters and its assertions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Number of cells/radios.
+int: NUM_NODES;
+
+% Maximum number of Physical Cell Identifiers to be assigned to the nodes.
+int: NUM_PCIS;
+
+% Number of edges between neighbor nodes. There is a edge (i,j) if and only
+% if nodes i and j are neighbors, i.e., an user equipment (UE) can make
+% handoff between i and j. Such edges are used to avoid **CONFLICTS**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_CONFLICT_EDGES;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_CONFLICT_EDGES, 1..2] of int: CONFLICT_EDGES; 
+
+% Number of undirect neighbor pairs (j, k) such that both j and k are direct
+% neighbors of node i, i.e., (j, k) exits if and only if exists (i, j) and 
+% (i, k). Nodes (i, k) can generate "confunsions" in the network if they have
+% the same PCI. Such edges are used to avoid/minimize **CONFUSIONS**.
+int: NUM_CONFUSION_EDGES;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_CONFUSION_EDGES, 1..2] of int: CONFUSION_EDGES; 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **CONFLICTS**.
+constraint 
+forall(i in 1..NUM_CONFLICT_EDGES)(
+    pci[CONFLICT_EDGES[i, 1]] != pci[CONFLICT_EDGES[i, 2]]
+);
+
+% Undirect neighbors must have different PCIs for avoid **CONFUSIONS**.
+constraint 
+forall(i in 1..NUM_CONFUSION_EDGES)(
+    pci[CONFUSION_EDGES[i, 1]] != pci[CONFUSION_EDGES[i, 2]]
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Just satisfy the problem.
+solve :: int_search(pci, smallest, indomain_min, complete) satisfy;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["node,pci\n"] ++
+[
+    show(node) ++ "," ++ show(pci[node]) ++ "\n"
+| node in 0..NUM_NODES-1
+]
diff --git a/osdf/optimizers/pciopt/solver/optimizer.py b/osdf/optimizers/pciopt/solver/optimizer.py
new file mode 100644
index 0000000..e9fcb0d
--- /dev/null
+++ b/osdf/optimizers/pciopt/solver/optimizer.py
@@ -0,0 +1,82 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import itertools
+
+import os
+import pymzn
+
+from osdf.logging.osdf_logging import debug_log
+from .pci_utils import get_id
+
+BASE_DIR = os.path.dirname(__file__)
+MZN_FILE_NAME = os.path.join(BASE_DIR, 'no_conflicts_no_confusion.mzn')
+
+
+def pci_optimize(cell_id, network_cell_info, cell_info_list):
+    debug_log.debug("Cell ID {} ".format(cell_id))
+    dzn_data = {}
+    dzn_data['NUM_NODES'] = len(cell_info_list)
+    dzn_data['NUM_PCIS'] = len(cell_info_list)
+
+    conflict_edges = get_conflict_edges(cell_id, network_cell_info)
+
+    dzn_data['NUM_CONFLICT_EDGES'] = len(conflict_edges)
+    dzn_data['CONFLICT_EDGES'] = conflict_edges
+
+    confusion_edges = get_confusion_edges(cell_id, network_cell_info)
+
+    dzn_data['NUM_CONFUSION_EDGES'] = len(confusion_edges)
+    dzn_data['CONFUSION_EDGES'] = confusion_edges
+
+    return solve(dzn_data)
+
+def solve(dzn_data):
+    return pymzn.minizinc(MZN_FILE_NAME, data=dzn_data)
+
+
+def get_conflict_edges(cell_id, network_cell_info):
+    conflict_edges = []
+    for cell in network_cell_info['cell_list']:
+
+        if cell_id == cell['cell_id']:
+            add_to_conflict_edges(network_cell_info, cell, conflict_edges)
+    return conflict_edges
+
+
+def add_to_conflict_edges(network_cell_info, cell, conflict_edges):
+    cell_id = cell['cell_id']
+    for nbr in cell.get('nbr_list', []):
+        conflict_edges.append([get_id(network_cell_info, cell_id), get_id(network_cell_info, nbr['cellId'])])
+
+
+
+def get_confusion_edges(cell_id, network_cell_info):
+    confusion_edges = []
+    for cell in network_cell_info['cell_list']:
+        if cell_id == cell['cell_id']:
+            return add_to_confusion_edges(network_cell_info, cell)
+    return confusion_edges
+
+
+def add_to_confusion_edges(network_cell_info, cell):
+    cell_id = cell['cell_id']
+    nbr_list = []
+    for nbr in cell.get('nbr_list', []):
+        nbr_list.append(get_id(network_cell_info, nbr['cellId']))
+    return [list(elem) for elem in list(itertools.combinations(nbr_list, 2))]
diff --git a/osdf/optimizers/pciopt/solver/pci_utils.py b/osdf/optimizers/pciopt/solver/pci_utils.py
new file mode 100644
index 0000000..71b5dd2
--- /dev/null
+++ b/osdf/optimizers/pciopt/solver/pci_utils.py
@@ -0,0 +1,39 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+
+def get_id(network_cell_info, cell_id):
+    for i in network_cell_info['cell_list']:
+        if i['cell_id'] == cell_id:
+            return i['id']
+    return None
+
+
+def get_cell_id(network_cell_info, id):
+    for i in network_cell_info['cell_list']:
+        if i['id'] == id:
+            return i['cell_id']
+    return None
+
+def get_pci_value(network_cell_info, id):
+    cell_id = get_cell_id(network_cell_info, id)
+    for i in network_cell_info['cell_list']:
+        for j in i['nbr_list']:
+            if cell_id == j['cellId']:
+                return j['pciValue']
+    return None