| /* |
| * Copyright 2019-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 done in Nokia Bell Labs. |
| * |
| */ |
| |
| package org.onosproject.net.optical.util; |
| |
| |
| import org.onlab.util.Frequency; |
| import org.onosproject.net.ChannelSpacing; |
| import org.onosproject.net.GridType; |
| import org.onosproject.net.OchSignal; |
| import org.slf4j.Logger; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import static org.slf4j.LoggerFactory.getLogger; |
| |
| |
| /** |
| * Optical Channel Utility is a set of methods to convert different |
| * set of parameters to the OchSignal instance and backwards. |
| */ |
| public final class OpticalChannelUtility { |
| |
| private static final Logger log = getLogger(OpticalChannelUtility.class); |
| private static final double SLOT_GRANULARITY_CONSTANT = 12.5; |
| private static final int NOMINAL_CENTRAL_FREQUENCY_GHZ = 193100; // According to ITU-T 694.1 |
| |
| private OpticalChannelUtility() {} |
| |
| /** |
| * This method creates OchSignal instance based on Central Frequency and |
| * the Slot Width of the channel. |
| * @param centralFrequency - central frequency of the connection. |
| * @param slotWidth - bandwidth of the optical channel. |
| * @param gridType - type of the frequency grid. |
| * @param channelSpacing - channel spacing. |
| * @return - returns created instance of OchSignal. |
| */ |
| public static final OchSignal createOchSignal(Frequency centralFrequency, Frequency slotWidth, |
| GridType gridType, ChannelSpacing channelSpacing) { |
| |
| int spacingMultiplier = computeSpacingMultiplier(centralFrequency, channelSpacing); |
| int slotGranularity = computeSlotGranularity(slotWidth); |
| |
| return (new OchSignal(gridType, channelSpacing, spacingMultiplier, slotGranularity)); |
| } |
| |
| /** |
| * This method creates OchSignal instance from frequency bounds. |
| * @param lowerBound - lower bound of the frequency. |
| * @param upperBound - upper bound of the frequency. |
| * @param gridType - type of the frequency grid. |
| * @param channelSpacing - channel spacing. |
| * @return - returns created instance of OchSignal. |
| */ |
| public static final OchSignal createOchSignalFromBounds( |
| Frequency lowerBound, Frequency upperBound, GridType gridType, |
| ChannelSpacing channelSpacing) { |
| |
| // Transferring everything to the frequencies |
| Frequency slotWidth = upperBound.subtract(lowerBound); |
| Frequency halfBw = slotWidth.floorDivision(2); |
| Frequency centralFrequency = lowerBound.add(halfBw); |
| |
| int spacingMultiplier = computeSpacingMultiplier(centralFrequency, channelSpacing); |
| int slotGranularity = computeSlotGranularity(slotWidth); |
| |
| return (new OchSignal(gridType, channelSpacing, spacingMultiplier, slotGranularity)); |
| } |
| |
| /** |
| * This method extracts frequency bounds from OchSignal instance. |
| * @param signal - OchSignal instance. |
| * @param channelSpacing - channel spacing. |
| * @return - HashMap with upper and lower bounds of frequency. |
| */ |
| public static final Map<String, Frequency> extractOchFreqBounds(OchSignal signal, ChannelSpacing channelSpacing) { |
| |
| // Initializing variables |
| int spacingMultiplier = signal.spacingMultiplier(); |
| int slotGranularity = signal.slotGranularity(); |
| |
| // Computing central frequency |
| Frequency central = computeCentralFrequency(spacingMultiplier, channelSpacing); |
| |
| // Computing HALF of slot width |
| Frequency halfSlotWidth = computeSlotWidth(slotGranularity).floorDivision(2); |
| |
| // Getting frequency bounds |
| Frequency minFreq = central.subtract(halfSlotWidth); |
| Frequency maxFreq = central.add(halfSlotWidth); |
| |
| Map<String, Frequency> freqs = new HashMap<String, Frequency>(); |
| freqs.put("minFreq", minFreq); |
| freqs.put("maxFreq", maxFreq); |
| |
| return freqs; |
| } |
| |
| /** |
| * This method extracts Central Frequency and Slot Width from OchSignal instance. |
| * @param signal - OchSignal instance. |
| * @param channelSpacing - channel spacing. |
| * @return - HashMap with upper and lower bounds of frequency. |
| */ |
| public static final Map<String, Frequency> extractOch(OchSignal signal, ChannelSpacing channelSpacing) { |
| |
| // Initializing variables |
| int spacingMultiplier = signal.spacingMultiplier(); |
| int slotGranularity = signal.slotGranularity(); |
| |
| // Computing central frequency |
| Frequency central = computeCentralFrequency(spacingMultiplier, channelSpacing); |
| // Computing slot width |
| Frequency sw = computeSlotWidth(slotGranularity); |
| |
| Map<String, Frequency> freqs = new HashMap<String, Frequency>(); |
| freqs.put("centralFrequency", central); |
| freqs.put("slotWidth", sw); |
| |
| return freqs; |
| } |
| |
| /** |
| * This method computes the Spacing Multiplier value |
| * from Central Frequency and Channel Spacing values. |
| * @param centralFrequency - central frequency. |
| * @param channelSpacing - channel spacing. |
| * @return - computed spacing multiplier. |
| */ |
| public static final int computeSpacingMultiplier( |
| Frequency centralFrequency, ChannelSpacing channelSpacing) { |
| |
| double centfreq = Double.parseDouble(String.valueOf(centralFrequency.asGHz())); |
| // Computing spacing multiplier from definition (see OchSignal class comments) |
| double spMult = (centfreq - NOMINAL_CENTRAL_FREQUENCY_GHZ) / |
| Double.parseDouble(String.valueOf(channelSpacing.frequency().asGHz())); |
| |
| return ((int) (spMult)); |
| } |
| |
| /** |
| * This method computes Slot Granularity from Slot Width value. |
| * @param slotWidth - slot width. |
| * @return - computed slot granularity. |
| */ |
| public static final int computeSlotGranularity(Frequency slotWidth) { |
| |
| double slotw = Double.parseDouble(String.valueOf(slotWidth.asGHz())); |
| // Computing according to the definition |
| double slotgr = slotw / SLOT_GRANULARITY_CONSTANT; |
| |
| return ((int) slotgr); |
| } |
| |
| /** |
| * This method computes the Central Frequency value |
| * from Spacing Multiplier and Channel Spacing values. |
| * @param spacingMultiplier - spacing multiplier. |
| * @param channelSpacing - channel spacing. |
| * @return - central frequency as an instance of Frequency. |
| */ |
| public static final Frequency computeCentralFrequency( |
| int spacingMultiplier, ChannelSpacing channelSpacing) { |
| |
| // Computing central frequency |
| double centralFreq = NOMINAL_CENTRAL_FREQUENCY_GHZ + spacingMultiplier * |
| Double.parseDouble(String.valueOf(channelSpacing.frequency().asGHz())); |
| |
| return Frequency.ofGHz(centralFreq); |
| } |
| |
| /** |
| * This method computes Slot Width value from Slot Granularity value. |
| * @param slotGranularity - slot granularity. |
| * @return - slot width as an instance of Frequency. |
| */ |
| public static final Frequency computeSlotWidth(int slotGranularity) { |
| |
| // Computing slot width |
| double slotWidth = slotGranularity * SLOT_GRANULARITY_CONSTANT; |
| |
| return Frequency.ofGHz(slotWidth); |
| } |
| |
| } |