osdf rearchitecture into apps and libs

Change-Id: I2db2f8e252bd5e60807b2ffabf5a5b193a789f7a
Signed-off-by: vrvarma <vv8305@att.com>
Issue-ID: OPTFRA-637

6 files changed, 501 insertions, 0 deletions

diff --git a/apps/pci/optimizers/solver/__init__.py b/apps/pci/optimizers/solver/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/apps/pci/optimizers/solver/__init__.py
diff --git a/apps/pci/optimizers/solver/min_confusion.mzn b/apps/pci/optimizers/solver/min_confusion.mzn
new file mode 100644
index 0000000..ff56c18
--- /dev/null
+++ b/apps/pci/optimizers/solver/min_confusion.mzn
@@ -0,0 +1,98 @@
+% -------------------------------------------------------------------------
+%   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 **COLLISION**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% 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_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 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 **COLLISION**.
+constraint
+forall(i in 1..NUM_NEIGHBORS)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Total number of confusions.
+var int: total_confusions =
+    sum([bool2int(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] ==
+                  pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+         | i in 1..NUM_SECOND_LEVEL_NEIGHBORS]);
+
+% 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(SECOND_LEVEL_NEIGHBORS[i, 1]) ++ "," ++
+    show(SECOND_LEVEL_NEIGHBORS[i, 2])
+| i in 1..NUM_SECOND_LEVEL_NEIGHBORS where
+  fix(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] == pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+]
diff --git a/apps/pci/optimizers/solver/min_confusion_inl.mzn b/apps/pci/optimizers/solver/min_confusion_inl.mzn
new file mode 100644
index 0000000..0f0fc91
--- /dev/null
+++ b/apps/pci/optimizers/solver/min_confusion_inl.mzn
@@ -0,0 +1,140 @@
+% -------------------------------------------------------------------------
+%   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 **COLLISION**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% 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_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+% Number of ignorable neighbor links. Such links can be ignored during
+% optimization if needed.
+int: NUM_IGNORABLE_NEIGHBOR_LINKS;
+
+% The links that can be ignored if needed. Each line represents the two ends
+% of the links, like the previous structures.
+array[1..NUM_IGNORABLE_NEIGHBOR_LINKS, 1..2] of int: IGNORABLE_NEIGHBOR_LINKS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+array[1..NUM_IGNORABLE_NEIGHBOR_LINKS] of var 0..1: used_ignorables;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **COLLISION**.
+% Forced links.
+constraint
+forall(i in 1..NUM_NEIGHBORS, j in 1..NUM_IGNORABLE_NEIGHBOR_LINKS
+    where
+        NEIGHBORS[i, 1] != IGNORABLE_NEIGHBOR_LINKS[j, 1] \/
+        NEIGHBORS[i, 2] != IGNORABLE_NEIGHBOR_LINKS[j, 2]
+)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+
+% Ignorable links.
+constraint
+forall(i in 1..NUM_NEIGHBORS, j in 1..NUM_IGNORABLE_NEIGHBOR_LINKS
+    where
+        NEIGHBORS[i, 1] == IGNORABLE_NEIGHBOR_LINKS[j, 1] /\
+        NEIGHBORS[i, 2] == IGNORABLE_NEIGHBOR_LINKS[j, 2]
+)(
+    used_ignorables[j] >= bool2int(pci[NEIGHBORS[i, 1]] == pci[NEIGHBORS[i, 2]])
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Total number of confusions.
+var int: total_confusions =
+    sum([bool2int(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] ==
+                  pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+         | i in 1..NUM_SECOND_LEVEL_NEIGHBORS]);
+
+% Total number of used ignorables links.
+var int: total_used_ignorables = sum(used_ignorables);
+
+solve :: int_search(pci, smallest, indomain_min, complete)
+
+% Minimize the total number of confusions.
+%minimize total_confusions;
+
+% Minimize the total number of confusions first,
+% then the number of used ignorables links.
+minimize (2 * NUM_IGNORABLE_NEIGHBOR_LINKS * total_confusions) +
+         total_used_ignorables;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["PCI assigment"] ++
+["\nnode,pci"] ++
+[
+    "\n" ++ show(node) ++ "," ++ show(pci[node])
+| node in 0..NUM_NODES-1
+] ++
+["\n\nTotal used ignorables links: " ++ show(total_used_ignorables)] ++
+["\nUsed ignorables links: "] ++
+[
+    "\n" ++ show(IGNORABLE_NEIGHBOR_LINKS[i, 1]) ++
+    ","  ++ show(IGNORABLE_NEIGHBOR_LINKS[i, 2])
+    | i in 1..NUM_IGNORABLE_NEIGHBOR_LINKS where fix(used_ignorables[i] > 0)
+] ++
+["\n\nConfusions"] ++
+["\nTotal confusions: " ++ show(total_confusions)] ++
+["\nConfusion pairs"] ++
+[
+    "\n" ++ show(SECOND_LEVEL_NEIGHBORS[i, 1]) ++ "," ++
+    show(SECOND_LEVEL_NEIGHBORS[i, 2])
+    | i in 1..NUM_SECOND_LEVEL_NEIGHBORS where
+      fix(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] == pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+]
+
diff --git a/apps/pci/optimizers/solver/no_conflicts_no_confusion.mzn b/apps/pci/optimizers/solver/no_conflicts_no_confusion.mzn
new file mode 100644
index 0000000..0a9b3e3
--- /dev/null
+++ b/apps/pci/optimizers/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 **COLLISIONS**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% 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_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 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 **COLLISION**.
+constraint
+forall(i in 1..NUM_NEIGHBORS)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+% Undirect neighbors must have different PCIs for avoid **CONFUSIONS**.
+constraint
+forall(i in 1..NUM_SECOND_LEVEL_NEIGHBORS)(
+    pci[SECOND_LEVEL_NEIGHBORS[i, 1]] != pci[SECOND_LEVEL_NEIGHBORS[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/apps/pci/optimizers/solver/optimizer.py b/apps/pci/optimizers/solver/optimizer.py
new file mode 100644
index 0000000..0a6d5a4
--- /dev/null
+++ b/apps/pci/optimizers/solver/optimizer.py
@@ -0,0 +1,137 @@
+# -------------------------------------------------------------------------
+#   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
+from collections import defaultdict
+
+import pymzn
+
+from .pci_utils import get_id
+
+BASE_DIR = os.path.dirname(__file__)
+
+
+def pci_optimize(network_cell_info, cell_info_list, request_json):
+    neighbor_edges = get_neighbor_list(network_cell_info)
+    second_level_edges = get_second_level_neighbor(network_cell_info)
+    ignorable_links = get_ignorable_links(network_cell_info, request_json)
+    anr_flag = is_anr(request_json)
+
+    dzn_data = build_dzn_data(cell_info_list, ignorable_links, neighbor_edges, second_level_edges, anr_flag)
+
+    return build_pci_solution(dzn_data, ignorable_links, anr_flag)
+
+
+def build_pci_solution(dzn_data, ignorable_links, anr_flag):
+    mzn_solution = solve(get_mzn_model(anr_flag), dzn_data)
+
+    solution = {'pci': mzn_solution[0]['pci']}
+
+    if anr_flag:
+        removables = defaultdict(list)
+        used_ignorables = mzn_solution[0]['used_ignorables']
+        index = 0
+        for i in ignorable_links:
+            if used_ignorables[index] > 0:
+                removables[i[0]].append(i[1])
+            index += 1
+        solution['removables'] = removables
+    return solution
+
+
+def build_dzn_data(cell_info_list, ignorable_links, neighbor_edges, second_level_edges, anr_flag):
+    dzn_data = {
+        'NUM_NODES': len(cell_info_list),
+        'NUM_PCIS': len(cell_info_list),
+        'NUM_NEIGHBORS': len(neighbor_edges),
+        'NEIGHBORS': get_list(neighbor_edges),
+        'NUM_SECOND_LEVEL_NEIGHBORS': len(second_level_edges),
+        'SECOND_LEVEL_NEIGHBORS': get_list(second_level_edges)
+    }
+    if anr_flag:
+        dzn_data['NUM_IGNORABLE_NEIGHBOR_LINKS'] = len(ignorable_links)
+        dzn_data['IGNORABLE_NEIGHBOR_LINKS'] = get_list(ignorable_links)
+    return dzn_data
+
+
+def get_mzn_model(anr_flag):
+    if anr_flag:
+        mzn_model = os.path.join(BASE_DIR, 'min_confusion_inl.mzn')
+    else:
+        mzn_model = os.path.join(BASE_DIR, 'no_conflicts_no_confusion.mzn')
+    return mzn_model
+
+
+def is_anr(request_json):
+    return 'pci-anr' in request_json["requestInfo"]["optimizers"]
+
+
+def get_list(edge_list):
+    array_list = []
+    for s in edge_list:
+        array_list.append([s[0], s[1]])
+    return sorted(array_list)
+
+
+def solve(mzn_model, dzn_data):
+    return pymzn.minizinc(mzn=mzn_model, data=dzn_data)
+
+
+def get_neighbor_list(network_cell_info):
+    neighbor_list = set()
+    for cell in network_cell_info['cell_list']:
+        add_to_neighbor_list(network_cell_info, cell, neighbor_list)
+    return neighbor_list
+
+
+def add_to_neighbor_list(network_cell_info, cell, neighbor_list):
+    for nbr in cell.get('nbr_list', []):
+        host_id = cell['id']
+        nbr_id = get_id(network_cell_info, nbr['targetCellId'])
+        if nbr_id and host_id != nbr_id:
+            neighbor_list.add((host_id, nbr_id))
+
+
+def get_second_level_neighbor(network_cell_info):
+    second_neighbor_list = set()
+    for cell in network_cell_info['cell_list']:
+        comb_list = build_second_level_list(network_cell_info, cell)
+        for comb in comb_list:
+            if comb[0] and comb[1]:
+                second_neighbor_list.add((comb[0], comb[1]))
+    return sorted(second_neighbor_list)
+
+
+def build_second_level_list(network_cell_info, cell):
+    second_nbr_list = []
+    for nbr in cell.get('nbr_list', []):
+        second_nbr_list.append(get_id(network_cell_info, nbr['targetCellId']))
+    return [list(elem) for elem in list(itertools.combinations(second_nbr_list, 2))]
+
+
+def get_ignorable_links(network_cell_info, request_json):
+    ignorable_list = set()
+    anr_input_list = request_json["cellInfo"].get('anrInputList', [])
+    if anr_input_list:
+        for anr_info in anr_input_list:
+            cell_id = get_id(network_cell_info, anr_info['cellId'])
+            anr_removable = anr_info.get('removeableNeighbors', [])
+            for anr in anr_removable:
+                ignorable_list.add((cell_id, get_id(network_cell_info, anr)))
+    return ignorable_list
diff --git a/apps/pci/optimizers/solver/pci_utils.py b/apps/pci/optimizers/solver/pci_utils.py
new file mode 100644
index 0000000..04829cf
--- /dev/null
+++ b/apps/pci/optimizers/solver/pci_utils.py
@@ -0,0 +1,40 @@
+# -------------------------------------------------------------------------
+#   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['targetCellId']:
+                return j['pciValue']
+    return None