Ivan Eroshkin | 2947ed5 | 2019-10-30 14:23:58 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2019-present Open Networking Foundation |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| 5 | * use this file except in compliance with the License. You may obtain a copy of |
| 6 | * the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 12 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 13 | * License for the specific language governing permissions and limitations under |
| 14 | * the License. |
| 15 | * |
| 16 | * This work was done in Nokia Bell Labs. |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | package org.onosproject.net.optical.util; |
| 21 | |
| 22 | |
| 23 | import org.onlab.util.Frequency; |
| 24 | import org.onosproject.net.ChannelSpacing; |
| 25 | import org.onosproject.net.GridType; |
| 26 | import org.onosproject.net.OchSignal; |
| 27 | import org.slf4j.Logger; |
| 28 | |
| 29 | import java.util.HashMap; |
| 30 | import java.util.Map; |
| 31 | |
| 32 | import static org.slf4j.LoggerFactory.getLogger; |
| 33 | |
| 34 | |
| 35 | /** |
| 36 | * Optical Channel Utility is a set of methods to convert different |
| 37 | * set of parameters to the OchSignal instance and backwards. |
| 38 | */ |
| 39 | public final class OpticalChannelUtility { |
| 40 | |
| 41 | private static final Logger log = getLogger(OpticalChannelUtility.class); |
| 42 | private static final double SLOT_GRANULARITY_CONSTANT = 12.5; |
| 43 | private static final int NOMINAL_CENTRAL_FREQUENCY_GHZ = 193100; // According to ITU-T 694.1 |
| 44 | |
| 45 | private OpticalChannelUtility() {} |
| 46 | |
| 47 | /** |
| 48 | * This method creates OchSignal instance based on Central Frequency and |
| 49 | * the Slot Width of the channel. |
| 50 | * @param centralFrequency - central frequency of the connection. |
| 51 | * @param slotWidth - bandwidth of the optical channel. |
| 52 | * @param gridType - type of the frequency grid. |
| 53 | * @param channelSpacing - channel spacing. |
| 54 | * @return - returns created instance of OchSignal. |
| 55 | */ |
| 56 | public static final OchSignal createOchSignal(Frequency centralFrequency, Frequency slotWidth, |
| 57 | GridType gridType, ChannelSpacing channelSpacing) { |
| 58 | |
| 59 | int spacingMultiplier = computeSpacingMultiplier(centralFrequency, channelSpacing); |
| 60 | int slotGranularity = computeSlotGranularity(slotWidth); |
| 61 | |
| 62 | return (new OchSignal(gridType, channelSpacing, spacingMultiplier, slotGranularity)); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * This method creates OchSignal instance from frequency bounds. |
| 67 | * @param lowerBound - lower bound of the frequency. |
| 68 | * @param upperBound - upper bound of the frequency. |
| 69 | * @param gridType - type of the frequency grid. |
| 70 | * @param channelSpacing - channel spacing. |
| 71 | * @return - returns created instance of OchSignal. |
| 72 | */ |
| 73 | public static final OchSignal createOchSignalFromBounds( |
| 74 | Frequency lowerBound, Frequency upperBound, GridType gridType, |
| 75 | ChannelSpacing channelSpacing) { |
| 76 | |
| 77 | // Transferring everything to the frequencies |
| 78 | Frequency slotWidth = upperBound.subtract(lowerBound); |
| 79 | Frequency halfBw = slotWidth.floorDivision(2); |
| 80 | Frequency centralFrequency = lowerBound.add(halfBw); |
| 81 | |
| 82 | int spacingMultiplier = computeSpacingMultiplier(centralFrequency, channelSpacing); |
| 83 | int slotGranularity = computeSlotGranularity(slotWidth); |
| 84 | |
| 85 | return (new OchSignal(gridType, channelSpacing, spacingMultiplier, slotGranularity)); |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * This method extracts frequency bounds from OchSignal instance. |
| 90 | * @param signal - OchSignal instance. |
| 91 | * @param channelSpacing - channel spacing. |
| 92 | * @return - HashMap with upper and lower bounds of frequency. |
| 93 | */ |
| 94 | public static final Map<String, Frequency> extractOchFreqBounds(OchSignal signal, ChannelSpacing channelSpacing) { |
| 95 | |
| 96 | // Initializing variables |
| 97 | int spacingMultiplier = signal.spacingMultiplier(); |
| 98 | int slotGranularity = signal.slotGranularity(); |
| 99 | |
| 100 | // Computing central frequency |
| 101 | Frequency central = computeCentralFrequency(spacingMultiplier, channelSpacing); |
| 102 | |
| 103 | // Computing HALF of slot width |
| 104 | Frequency halfSlotWidth = computeSlotWidth(slotGranularity).floorDivision(2); |
| 105 | |
| 106 | // Getting frequency bounds |
| 107 | Frequency minFreq = central.subtract(halfSlotWidth); |
| 108 | Frequency maxFreq = central.add(halfSlotWidth); |
| 109 | |
| 110 | Map<String, Frequency> freqs = new HashMap<String, Frequency>(); |
| 111 | freqs.put("minFreq", minFreq); |
| 112 | freqs.put("maxFreq", maxFreq); |
| 113 | |
| 114 | return freqs; |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * This method extracts Central Frequency and Slot Width from OchSignal instance. |
| 119 | * @param signal - OchSignal instance. |
| 120 | * @param channelSpacing - channel spacing. |
| 121 | * @return - HashMap with upper and lower bounds of frequency. |
| 122 | */ |
| 123 | public static final Map<String, Frequency> extractOch(OchSignal signal, ChannelSpacing channelSpacing) { |
| 124 | |
| 125 | // Initializing variables |
| 126 | int spacingMultiplier = signal.spacingMultiplier(); |
| 127 | int slotGranularity = signal.slotGranularity(); |
| 128 | |
| 129 | // Computing central frequency |
| 130 | Frequency central = computeCentralFrequency(spacingMultiplier, channelSpacing); |
| 131 | // Computing slot width |
| 132 | Frequency sw = computeSlotWidth(slotGranularity); |
| 133 | |
| 134 | Map<String, Frequency> freqs = new HashMap<String, Frequency>(); |
| 135 | freqs.put("centralFrequency", central); |
| 136 | freqs.put("slotWidth", sw); |
| 137 | |
| 138 | return freqs; |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * This method computes the Spacing Multiplier value |
| 143 | * from Central Frequency and Channel Spacing values. |
| 144 | * @param centralFrequency - central frequency. |
| 145 | * @param channelSpacing - channel spacing. |
| 146 | * @return - computed spacing multiplier. |
| 147 | */ |
| 148 | public static final int computeSpacingMultiplier( |
| 149 | Frequency centralFrequency, ChannelSpacing channelSpacing) { |
| 150 | |
| 151 | double centfreq = Double.parseDouble(String.valueOf(centralFrequency.asGHz())); |
| 152 | // Computing spacing multiplier from definition (see OchSignal class comments) |
| 153 | double spMult = (centfreq - NOMINAL_CENTRAL_FREQUENCY_GHZ) / |
| 154 | Double.parseDouble(String.valueOf(channelSpacing.frequency().asGHz())); |
| 155 | |
| 156 | return ((int) (spMult)); |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * This method computes Slot Granularity from Slot Width value. |
| 161 | * @param slotWidth - slot width. |
| 162 | * @return - computed slot granularity. |
| 163 | */ |
| 164 | public static final int computeSlotGranularity(Frequency slotWidth) { |
| 165 | |
| 166 | double slotw = Double.parseDouble(String.valueOf(slotWidth.asGHz())); |
| 167 | // Computing according to the definition |
| 168 | double slotgr = slotw / SLOT_GRANULARITY_CONSTANT; |
| 169 | |
| 170 | return ((int) slotgr); |
| 171 | } |
| 172 | |
| 173 | /** |
| 174 | * This method computes the Central Frequency value |
| 175 | * from Spacing Multiplier and Channel Spacing values. |
| 176 | * @param spacingMultiplier - spacing multiplier. |
| 177 | * @param channelSpacing - channel spacing. |
| 178 | * @return - central frequency as an instance of Frequency. |
| 179 | */ |
| 180 | public static final Frequency computeCentralFrequency( |
| 181 | int spacingMultiplier, ChannelSpacing channelSpacing) { |
| 182 | |
| 183 | // Computing central frequency |
| 184 | double centralFreq = NOMINAL_CENTRAL_FREQUENCY_GHZ + spacingMultiplier * |
| 185 | Double.parseDouble(String.valueOf(channelSpacing.frequency().asGHz())); |
| 186 | |
| 187 | return Frequency.ofGHz(centralFreq); |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * This method computes Slot Width value from Slot Granularity value. |
| 192 | * @param slotGranularity - slot granularity. |
| 193 | * @return - slot width as an instance of Frequency. |
| 194 | */ |
| 195 | public static final Frequency computeSlotWidth(int slotGranularity) { |
| 196 | |
| 197 | // Computing slot width |
| 198 | double slotWidth = slotGranularity * SLOT_GRANULARITY_CONSTANT; |
| 199 | |
| 200 | return Frequency.ofGHz(slotWidth); |
| 201 | } |
| 202 | |
| 203 | } |