diff --git a/core/api/src/main/java/org/onosproject/net/OchSignal.java b/core/api/src/main/java/org/onosproject/net/OchSignal.java
index 7f67df3..2234aaf 100644
--- a/core/api/src/main/java/org/onosproject/net/OchSignal.java
+++ b/core/api/src/main/java/org/onosproject/net/OchSignal.java
@@ -238,7 +238,7 @@
                 this.getClass().getSimpleName(),
                 spacingMultiplier,
                 (double) channelSpacing.frequency().asHz() / Frequency.ofGHz(1).asHz(),
-                (double) slotGranularity * ChannelSpacing.CHL_12P5GHZ.frequency().asHz()
+                (double) slotGranularity * channelSpacing.frequency().asHz()
                         / Frequency.ofGHz(1).asHz() / 2.0);
     }
 }
diff --git a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceDescriptionDiscovery.java b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceDescriptionDiscovery.java
index 59a5ef8..b6bac21 100644
--- a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceDescriptionDiscovery.java
+++ b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceDescriptionDiscovery.java
@@ -46,6 +46,7 @@
 import java.util.List;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.*;
 import static org.onosproject.net.optical.device.OchPortHelper.ochPortDescription;
 import static org.slf4j.LoggerFactory.getLogger;
 
@@ -60,24 +61,8 @@
 
     private static final Logger log = getLogger(TapiDeviceDescriptionDiscovery.class);
     private static final String SIP_REQUEST_DATA_API = "/data/context/";
-    public static final String SERVICE_INTERFACE_POINT = "service-interface-point";
-    public static final String UUID = "uuid";
-    public static final String MEDIA_CHANNEL_SERVICE_INTERFACE_POINT_SPEC =
-            "media-channel-service-interface-point-spec";
-    public static final String MC_POOL = "mc-pool";
-    public static final String LAYER_PROTOCOL_NAME = "layer-protocol-name";
-    public static final String PHOTONIC_MEDIA = "PHOTONIC_MEDIA";
-    public static final String SUPPORTED_LAYER_PROTOCOL_QUALIFIER = "supported-layer-protocol-qualifier";
-    public static final String PHOTONIC_LAYER_QUALIFIER_NMC = "PHOTONIC_LAYER_QUALIFIER_NMC";
-    public static final String FREQUENCY_CONSTRAINT = "frequency-constraint";
-    public static final String GRID_TYPE = "grid-type";
-    public static final String ADJUSTMENT_GRANULARITY = "adjustment-granularity";
-    public static final String UPPER_FREQUENCY = "upper-frequency";
-    public static final String LOWER_FREQUENCY = "lower-frequency";
-    public static final String AVAILABLE_SPECTRUM = "available-spectrum";
     private static PortNumber nPort = PortNumber.portNumber(1);
     private static final Object N_PORT_LOCK = new Object();
-    private static final long BASE_FREQUENCY = 193100000;   //Working in Mhz
 
     /**
      * Get the deviceId for which the methods apply.
@@ -149,6 +134,11 @@
                 String uuid = sipAttributes.get(UUID).textValue();
                 JsonNode mcPool = sipAttributes.get(MEDIA_CHANNEL_SERVICE_INTERFACE_POINT_SPEC).get(MC_POOL);
 
+                /*We create a sample OChSignal in the first position of the 50GHz DWDM Grid,
+                this should be replace for a OChSignal construct which has undefined spectrum.
+                OchSignal ochSignal = new OchSignal(GridType.DWDM, ChannelSpacing.CHL_50GHZ,
+                        0, 1);*/
+
                 OchSignal ochSignal = getOchSignal(mcPool);
                 synchronized (N_PORT_LOCK) {
                     //annotations(portNumber-uuid)
@@ -187,8 +177,10 @@
      * and spectrum-occupied tapi objects.
      **/
     private OchSignal getOchSignal(JsonNode mcPool) {
-        long availableUpperFrec = 0, availableLowerFrec = 0;
-        String availableAdjustmentGranularity = "", availableGridType = "";
+        long availableUpperFrec = 0;
+        long availableLowerFrec = 0;
+        String availableAdjustmentGranularity = "";
+        String availableGridType = "";
         JsonNode availableSpectrum = mcPool.get(AVAILABLE_SPECTRUM);
 
         /**At this time only the latest availableSpectrum is used**/
@@ -202,12 +194,13 @@
             availableGridType = availableSpec.get(FREQUENCY_CONSTRAINT).get(GRID_TYPE).textValue();
         }
 
-        int spacingMult = 0, slotGranularity = 1;
+        int spacingMult = 0;
+        int slotGranularity = 1;
         ChannelSpacing chSpacing = getChannelSpacing(availableAdjustmentGranularity);
         long spacingFrequency = chSpacing.frequency().asHz();
         long centralFrequency = (availableUpperFrec - (availableUpperFrec - availableLowerFrec) / 2);
 
-        GridType gridType = getGridType(availableGridType);
+        GridType gridType = GridType.valueOf(availableGridType);
         if (gridType == GridType.DWDM) {
             spacingMult = (int) ((centralFrequency - BASE_FREQUENCY) / toMbpsFromHz(spacingFrequency));
         } else if (gridType == GridType.CWDM) {
@@ -221,52 +214,4 @@
         return new OchSignal(gridType, chSpacing, spacingMult, slotGranularity);
     }
 
-    private int getSlotGranularity(ChannelSpacing chSpacing) {
-        if (chSpacing.equals(ChannelSpacing.CHL_100GHZ)) {
-            return 8;
-        } else if (chSpacing.equals(ChannelSpacing.CHL_50GHZ)) {
-            return 4;
-        } else if (chSpacing.equals(ChannelSpacing.CHL_25GHZ)) {
-            return 2;
-        } else if (chSpacing.equals(ChannelSpacing.CHL_12P5GHZ)) {
-            return 1;
-        } else {
-            return 0;
-        }
-    }
-
-    private GridType getGridType(String gridType) {
-        switch (gridType) {
-            case "DWDM":
-                return GridType.DWDM;
-            case "CWDM":
-                return GridType.CWDM;
-            case "FLEX":
-                return GridType.FLEX;
-            default:
-                return GridType.UNKNOWN;
-        }
-    }
-
-    private ChannelSpacing getChannelSpacing(String adjustmentGranularity) {
-        switch (adjustmentGranularity) {
-            case "G_100GHZ ":
-                return ChannelSpacing.CHL_100GHZ;
-            case "G_50GHZ":
-                return ChannelSpacing.CHL_50GHZ;
-            case "G_25GHZ":
-                return ChannelSpacing.CHL_25GHZ;
-            case "G_12_5GHZ ":
-                return ChannelSpacing.CHL_12P5GHZ;
-            case "G_6_25GHZ ":
-                return ChannelSpacing.CHL_6P25GHZ;
-            default:
-                return ChannelSpacing.CHL_0GHZ;
-        }
-    }
-
-    private static long toMbpsFromHz(long speed) {
-        return speed / 1000000;
-    }
-
 }
diff --git a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceHelper.java b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceHelper.java
new file mode 100644
index 0000000..11bf38c
--- /dev/null
+++ b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceHelper.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.
+ *
+ * This work was partially supported by EC H2020 project METRO-HAUL (761727).
+ */
+package org.onosproject.drivers.odtn.tapi;
+
+import org.onosproject.net.ChannelSpacing;
+
+/**
+ * Tapi 2.1 OLS device related helpers.
+ */
+public final class TapiDeviceHelper {
+
+    public static final String SERVICE_INTERFACE_POINT = "service-interface-point";
+    public static final String UUID = "uuid";
+    public static final String MEDIA_CHANNEL_SERVICE_INTERFACE_POINT_SPEC =
+            "media-channel-service-interface-point-spec";
+    public static final String MC_POOL = "mc-pool";
+    public static final String LAYER_PROTOCOL_NAME = "layer-protocol-name";
+    public static final String PHOTONIC_MEDIA = "PHOTONIC_MEDIA";
+    public static final String SUPPORTED_LAYER_PROTOCOL_QUALIFIER = "supported-layer-protocol-qualifier";
+    public static final String PHOTONIC_LAYER_QUALIFIER_NMC = "PHOTONIC_LAYER_QUALIFIER_NMC";
+    public static final String FREQUENCY_CONSTRAINT = "frequency-constraint";
+    public static final String GRID_TYPE = "grid-type";
+    public static final String ADJUSTMENT_GRANULARITY = "adjustment-granularity";
+    public static final String UPPER_FREQUENCY = "upper-frequency";
+    public static final String LOWER_FREQUENCY = "lower-frequency";
+    public static final String AVAILABLE_SPECTRUM = "available-spectrum";
+    public static final long BASE_FREQUENCY = 193100000;   //Working in Mhz
+
+    private TapiDeviceHelper(){}
+
+    /**
+     * Returns the slot granularity corresponding to a channelSpacing.
+     *
+     * @param chSpacing      OchSingal channel spacing {@link ChannelSpacing}
+     * @return OchSignal slot width granularity
+     */
+    public static int getSlotGranularity(ChannelSpacing chSpacing) {
+        if (chSpacing.equals(ChannelSpacing.CHL_100GHZ)) {
+            return 8;
+        } else if (chSpacing.equals(ChannelSpacing.CHL_50GHZ)) {
+            return 4;
+        } else if (chSpacing.equals(ChannelSpacing.CHL_25GHZ)) {
+            return 2;
+        } else if (chSpacing.equals(ChannelSpacing.CHL_12P5GHZ)) {
+            return 1;
+        } else {
+            return 0;
+        }
+    }
+
+    /**
+     * Returns the ChannelSpacing corresponding to an adjustmentGranularity.
+     *
+     * @param adjustmentGranularity {@link String}
+     * @return OchSingnal ChannelSpacing {@link ChannelSpacing}
+     */
+    public static ChannelSpacing getChannelSpacing(String adjustmentGranularity) {
+        switch (adjustmentGranularity) {
+            case "G_100GHZ ":
+                return ChannelSpacing.CHL_100GHZ;
+            case "G_50GHZ":
+                return ChannelSpacing.CHL_50GHZ;
+            case "G_25GHZ":
+                return ChannelSpacing.CHL_25GHZ;
+            case "G_12_5GHZ ":
+                return ChannelSpacing.CHL_12P5GHZ;
+            case "G_6_25GHZ ":
+                return ChannelSpacing.CHL_6P25GHZ;
+            default:
+                return ChannelSpacing.CHL_0GHZ;
+        }
+    }
+
+    /**
+     *  To Mbps conversion from Hz.
+     *
+     *  @param speed the speed in Hz
+     *  @return the speed in Mbps
+     */
+    public static long toMbpsFromHz(long speed) {
+        return speed / 1000000;
+    }
+}
diff --git a/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceLambdaQuery.java b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceLambdaQuery.java
new file mode 100644
index 0000000..f06c0b4
--- /dev/null
+++ b/drivers/odtn-driver/src/main/java/org/onosproject/drivers/odtn/tapi/TapiDeviceLambdaQuery.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.
+ *
+ * This work was partially supported by EC H2020 project METRO-HAUL (761727).
+ */
+package org.onosproject.drivers.odtn.tapi;
+
+import com.google.common.collect.ImmutableSet;
+import org.onosproject.net.Port;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.ChannelSpacing;
+import org.onosproject.net.GridType;
+import org.onosproject.net.OchSignal;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.behaviour.LambdaQuery;
+import org.onosproject.net.driver.AbstractHandlerBehaviour;
+import org.onosproject.protocol.rest.RestSBController;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.slf4j.Logger;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.MEDIA_CHANNEL_SERVICE_INTERFACE_POINT_SPEC;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.AVAILABLE_SPECTRUM;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.ADJUSTMENT_GRANULARITY;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.BASE_FREQUENCY;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.FREQUENCY_CONSTRAINT;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.GRID_TYPE;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.LOWER_FREQUENCY;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.MC_POOL;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.UPPER_FREQUENCY;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.toMbpsFromHz;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.getChannelSpacing;
+import static org.onosproject.drivers.odtn.tapi.TapiDeviceHelper.getSlotGranularity;
+
+import static org.slf4j.LoggerFactory.getLogger;
+import static com.google.common.base.Preconditions.checkNotNull;
+import org.onosproject.net.device.DeviceService;
+import javax.ws.rs.core.MediaType;
+
+
+
+/**
+ * Driver behavior of TAPI devices to discover the map of available lambdas of the ports.
+ */
+public class TapiDeviceLambdaQuery extends AbstractHandlerBehaviour
+        implements LambdaQuery {
+
+    private static final Logger log = getLogger(TapiDeviceLambdaQuery.class);
+    private static final String SIP_REQUEST_DATA_API = "/data/context/service-interface-point=";
+
+    /**
+     * Get the deviceId for which the methods apply.
+     *
+     * @return The deviceId as contained in the handler data
+     */
+    private DeviceId did() {
+        return handler().data().deviceId();
+    }
+
+    @Override
+    public Set<OchSignal> queryLambdas(PortNumber port) {
+        RestSBController controller = checkNotNull(handler().get(RestSBController.class));
+        DeviceService deviceService = checkNotNull(handler().get(DeviceService.class));
+        DeviceId deviceId = did();
+        Device dev = deviceService.getDevice(deviceId);
+        if (dev == null) {
+            log.error("Device {} does not exist", deviceId);
+        }
+        Port p = deviceService.getPort(dev.id(), port);
+        if (p == null) {
+            log.error("Port {} does not exist", port);
+        }
+        String uuid = p.annotations().value(port.toString());
+
+        try {
+            InputStream inputStream = controller.get(deviceId, SIP_REQUEST_DATA_API + uuid,
+                    MediaType.APPLICATION_JSON_TYPE);
+            log.debug("Service interface point UUID: {}", uuid);
+            JsonNode sipAttributes = new ObjectMapper().readTree(inputStream);
+            JsonNode mcPool = sipAttributes.get(MEDIA_CHANNEL_SERVICE_INTERFACE_POINT_SPEC).get(MC_POOL);
+
+            //This creates a hashset of OChSignals representing the spectrum availability at the target port.
+            Set<OchSignal> lambdas = getOchSignal(mcPool);
+            log.debug("Lambdas: {}", lambdas.toString());
+            return lambdas;
+
+        } catch (IOException e) {
+            log.error("Exception discoverPortDetails() {}", did(), e);
+            return ImmutableSet.of();
+        }
+    }
+
+    /**
+     * If SIP info match our criteria, SIP component shall includes mc-pool information which must be obtained in order
+     * to complete the OchSignal info. with the TAPI SIP information included in spectrum-supported, spectrum-available
+     * and spectrum-occupied tapi objects.
+     **/
+    private Set<OchSignal> getOchSignal(JsonNode mcPool) {
+
+        Set<OchSignal> lambdas = new LinkedHashSet<>();
+        long availableUpperFrec = 0;
+        long availableLowerFrec = 0;
+        String availableAdjustmentGranularity = "";
+        String availableGridType = "";
+        JsonNode availableSpectrum = mcPool.get(AVAILABLE_SPECTRUM);
+
+        /**At this time only the latest availableSpectrum is used**/
+        Iterator<JsonNode> iterAvailable = availableSpectrum.iterator();
+        while (iterAvailable.hasNext()) {
+            JsonNode availableSpec = iterAvailable.next();
+            availableUpperFrec = availableSpec.get(UPPER_FREQUENCY).asLong();
+            availableLowerFrec = availableSpec.get(LOWER_FREQUENCY).asLong();
+            availableAdjustmentGranularity = availableSpec.get(FREQUENCY_CONSTRAINT)
+                    .get(ADJUSTMENT_GRANULARITY).textValue();
+            availableGridType = availableSpec.get(FREQUENCY_CONSTRAINT).get(GRID_TYPE).textValue();
+
+            int spacingMult = 0;
+            int slotGranularity = 1;
+            ChannelSpacing chSpacing = getChannelSpacing(availableAdjustmentGranularity);
+            long spacingFrequency = chSpacing.frequency().asHz();
+            long centralFrequency = (availableUpperFrec - (availableUpperFrec - availableLowerFrec) / 2);
+
+            GridType gridType = GridType.valueOf(availableGridType);
+            if (gridType == GridType.DWDM) {
+                spacingMult = (int) ((centralFrequency - BASE_FREQUENCY) / toMbpsFromHz(spacingFrequency));
+                OchSignal ochSignal = new OchSignal(gridType, chSpacing, spacingMult, slotGranularity);
+                lambdas.add(ochSignal);
+            } else if (gridType == GridType.CWDM) {
+                log.warn("GridType CWDM. Not implemented");
+            } else if (gridType == GridType.FLEX) {
+                log.warn("GridType FLEX. Not implemented");
+                slotGranularity = getSlotGranularity(chSpacing);
+            } else {
+                log.warn("Unknown GridType");
+            }
+        }
+        return lambdas;
+    }
+
+}
\ No newline at end of file
diff --git a/drivers/odtn-driver/src/main/resources/odtn-drivers.xml b/drivers/odtn-driver/src/main/resources/odtn-drivers.xml
index bd3dff4..60fe17f 100644
--- a/drivers/odtn-driver/src/main/resources/odtn-drivers.xml
+++ b/drivers/odtn-driver/src/main/resources/odtn-drivers.xml
@@ -18,6 +18,8 @@
     <driver name="ols" manufacturer="tapi-swagger" hwVersion="0" swVersion="2.1">
         <behaviour api="org.onosproject.net.device.DeviceDescriptionDiscovery"
                    impl="org.onosproject.drivers.odtn.tapi.TapiDeviceDescriptionDiscovery"/>
+        <behaviour api ="org.onosproject.net.behaviour.LambdaQuery"
+                   impl="org.onosproject.drivers.odtn.tapi.TapiDeviceLambdaQuery"/>
         <!--<behaviour api="org.onosproject.net.flow.FlowRuleProgrammable"
                    impl="org.onosproject.drivers.odtn.TapiFlowRuleProgrammable-->
     </driver>