--- /dev/null
+/*
+ * Copyright © 2017 AT&T and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.transportpce.networkmodel.service;
+
+import org.opendaylight.yang.gen.v1.http.org.transportpce.b.c._interface.pathdescription.rev200629.path.description.AToZDirection;
+import org.opendaylight.yang.gen.v1.http.org.transportpce.b.c._interface.pathdescription.rev200629.path.description.ZToADirection;
+
+public interface NetworkModelWavelengthService {
+
+ /**
+ * Remove wavelength from available and add it to used wavelength list.
+ *
+ * @param atoZDirection AToZDirection: a to z path
+ * @param ztoADirection ZToADirection: z to a path
+ */
+ void useWavelengths(AToZDirection atoZDirection, ZToADirection ztoADirection);
+
+ /**
+ * Remove wavelength from used and add it to available wavelength list.
+ *
+ * @param atoZDirection AToZDirection: a to z path
+ * @param ztoADirection ZToADirection: z to a path
+ */
+ void freeWavelengths(AToZDirection atoZDirection, ZToADirection ztoADirection);
+
+}