diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..0a93004
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,38 @@
+name: Standard CI
+
+on:
+  push:
+    branches:
+      - main
+      - release
+  pull_request:
+    branches:
+      - main
+      - release
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 11
+
+      - name: Download & unzip protoc
+        run: |
+          wget https://github.com/protocolbuffers/protobuf/releases/download/v3.17.0/protoc-3.17.0-linux-x86_64.zip \
+            -O protoc-3.zip
+          unzip protoc-3.zip -d protoc-3
+          mv protoc-3/bin/protoc protoc
+
+      - name: Compile java files from `proto` file
+        run: |
+          mkdir -p src/main/java
+          ./protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+      - name: Build with Gradle
+        run: ./gradlew build
+        env:
+          USERNAME: ${{ github.actor }}
+          PASSWORD: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/publish-jar.yml b/.github/workflows/publish-jar.yml
new file mode 100644
index 0000000..80fbf66
--- /dev/null
+++ b/.github/workflows/publish-jar.yml
@@ -0,0 +1,45 @@
+name: Publish to GitHub Packages
+
+on: 
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 11
+
+      - name: Download & unzip protoc
+        run: |
+          wget https://github.com/protocolbuffers/protobuf/releases/download/v3.17.0/protoc-3.17.0-linux-x86_64.zip \
+            -O protoc-3.zip
+          unzip protoc-3.zip -d protoc-3
+          mv protoc-3/bin/protoc protoc
+
+      - name: Compile java files from `proto` file
+        run: |
+          ./protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+      # Publish slim JARS to Github Package Registry
+      - name: Publish package
+        run: ./gradlew publish
+        env:
+          USERNAME: ${{ github.actor }}
+          PASSWORD: ${{ secrets.GITHUB_TOKEN }}
+
+      # Automatically mark this tag as release on Github
+      - uses: actions/create-release@v1
+        id: create_release
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: false
+          # Release tags of format `1.2.3-beta1 / -alpha1 / -test1` are considered a pre-release
+          prerelease: ${{ contains(github.ref, 'test') || contains(github.ref, 'alpha') || contains(github.ref, 'beta') }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a8de083
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,61 @@
+#
+# Copyright 2018 Cyface GmbH
+#
+# This file is part of the Cyface Data Collector.
+#
+# The Cyface Data Collector is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# The Cyface Data Collector is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the Cyface Data Collector.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Eclipse Files
+.classpath
+.settings
+bin
+.project
+
+# Intellij Idea Files
+.idea
+.editorconfig
+out
+*.iml
+
+# Gradle Temporary Files
+.gradle
+build
+local.properties
+gradle.properties
+
+# Ignore local test maven repositories
+**/repo
+
+# Vim Temporary Files
+**/*.swp
+
+# Cyface Temporary Files
+**/file-uploads
+**/.vertx
+**/conf.json
+**/*.log
+**/secrets
+*.json
+
+# Generated java classes from proto files
+src/main/java/
+
+# Temporary Git Files
+**/*.orig
+
+# Ignore logging configurations
+**/logback.xml
+
+# Vertx Config files
+**/config.json
diff --git a/README.adoc b/README.adoc
new file mode 100644
index 0000000..096e9a7
--- /dev/null
+++ b/README.adoc
@@ -0,0 +1,75 @@
+= Cyface Protocol Buffer Messages
+
+This repository defines the Cyface Models as schemas such as Protocol Buffer Schemas.
+This allows to de-/serialize the Cyface Binary Data from in different programming languages.
+
+For more details on Protocol Buffers (short: Protobuf) check out it's link:https://developers.google.com/protocol-buffers[documentation].
+
+
+== Message Format Definitions
+
+This is a collection of `.proto` files describe the data structure of the Cyface Models.
+
+- This allows Protobuf to automatically de-/encode the the data from/to binary files.
+- Supports later extensions of the format with backward-compatibility
+- Following the link:https://developers.google.com/protocol-buffers/docs/style[Style Guide]
+
+At the time of writing the latest release is link:https://developers.google.com/protocol-buffers/docs/proto3[Protocol Buffer Version 3].
+
+
+=== Notes
+Reminders from the documentation which need to be considered for future updates:
+
+ - optional fields are default in proto3, `required` fields have been removed.
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#updating[Updating A Message Type]
+
+ - link:https://developers.google.com/protocol-buffers/docs/javatutorial#extending-a-protocol-buffer[Extending a Protocol Buffer]
+
+ - Deprecated field link:https://developers.google.com/protocol-buffers/docs/proto3#options[annotations]
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#default[Default values]
+
+ - Scalar message fields, once parsed, cannot tell if a field was not set or set the the default value afterwards.
+ - Default values are not serialized on the wire.
+ - Keep this in mind when defining e.g. booleans, make sure you want that "default" `false` behavior on.
+ 
+Other message types:
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#using_oneof[One-of] if only one of many fields can be set / should be interpreted. link:https://developers.google.com/protocol-buffers/docs/proto3#backwards-compatibility_issues[Be careful] with these fields.
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#maps[Maps]
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#json[JSON Mapping]
+ - There are also "well known" message types from Google, e.g. for `JSON`
+ - link:https://developers.google.com/protocol-buffers/docs/javatutorial#advanced-usage[Reflections]
+
+
+== Compiling the Message Definitions
+
+Generates serializer, deserializer, etc. in a chosen language, e.g. `.java` files for Java.
+
+Java classes can be compiled with link:https://developers.google.com/protocol-buffers/docs/javatutorial#compiling-your-protocol-buffers[protoc] (Protocol Buffers `v3.17.0`):
+
+  protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+However, the pre-compiled `JARs` are also published to the link:https://github.com/orgs/cyface-de/packages?repo_name=protos[Github Package Registry].
+
+- how to use with link:https://github.com/protocolbuffers/protobuf/tree/master/java#gradle[Gradle]
+- how to use with link:https://github.com/protocolbuffers/protobuf/tree/master/java#use-java-protocol-buffers-on-android[Android]
+
+The serializers encode the data in an efficient way, the decision process is documented link:https://cyface.atlassian.net/wiki/spaces/IM/pages/1535148033/Datenformat+bertragungsprotokoll+2021[internally].
+
+
+== Using the generated Code
+
+____
+Protocol Buffers and Object Oriented Design Protocol buffer classes are basically dumb data holders (like structs in C); they don't make good first class citizens in an object model. If you want to add richer behavior to a generated class, the best way to do this is to wrap the generated protocol buffer class in an application-specific class.
+____
+link:https://developers.google.com/protocol-buffers/docs/javatutorial#builders[Source]
+
+
+[#_licensing]
+== Licensing
+
+Copyright (C) 2021 Cyface GmbH - All Rights Reserved
+Unauthorized copying of this file, via any medium is strictly prohibited
+Proprietary and confidential
diff --git a/README.md b/README.md
deleted file mode 100644
index 5be06fa..0000000
--- a/README.md
+++ /dev/null
@@ -1,2 +0,0 @@
-# protos
-All Prototol Buffer files (.proto) for our serializations.
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..9acac47
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2021 Cyface GmbH
+ *
+ * This file is part of the Cyface Protocol Buffer Messages.
+ *
+ *  The Cyface Protocol Buffer Messages is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The Cyface Protocol Buffer Messages is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with the Cyface Protocol Buffer Messages.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/**
+ * The root build gradle file.
+ *
+ * @author Armin Schnabel
+ */
+buildscript {
+  repositories {
+    mavenCentral()
+  }
+}
+
+plugins {
+  id 'java'
+  id 'application'
+  id 'eclipse'
+  id 'idea'
+  id 'maven-publish'
+  //noinspection SpellCheckingInspection
+  id 'com.github.johnrengelman.shadow' version '6.1.0' apply false
+}
+
+group = 'de.cyface'
+version = '0.0.0'
+
+tasks.withType(JavaCompile) {
+  options.encoding = 'UTF-8'
+
+  sourceCompatibility = JavaVersion.VERSION_11
+  targetCompatibility = JavaVersion.VERSION_11
+}
+
+ext {
+  commonsLangVersion = '3.8.1'
+  gradleWrapperVersion = '6.8.3'
+  protobufVersion = '3.17.0'
+
+  // Versions of testing dependencies
+  junitVersion = '5.7.0'
+  mockitoVersion = '3.3.3'
+  hamcrestVersion = '2.2'
+  flapdoodleVersion = '3.0.0'
+}
+
+wrapper {
+  gradleVersion = "$gradleWrapperVersion"
+}
+
+repositories {
+  mavenCentral()
+}
+
+// Code Quality Checker
+dependencies {
+  // Protobuf generated java files
+  implementation "com.google.protobuf:protobuf-java:$protobufVersion"
+
+  // Utility
+  implementation "org.apache.commons:commons-lang3:$commonsLangVersion" // Using Validate
+
+  // Testing Dependencies
+  testImplementation(platform("org.junit:junit-bom:$junitVersion"))
+  testImplementation "org.junit.jupiter:junit-jupiter-api"
+  //testImplementation "org.junit.jupiter:junit-jupiter-params"  // Required for parameterized tests
+  testImplementation "org.hamcrest:hamcrest:$hamcrestVersion"
+  testImplementation "org.mockito:mockito-core:$mockitoVersion"
+  testImplementation "org.mockito:mockito-junit-jupiter:$mockitoVersion"
+  testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine"
+}
+
+test {
+  useJUnitPlatform()
+  testLogging {
+    events "passed", "skipped", "failed"
+  }
+}
+
+// Definitions for the maven-publish Plugin
+publishing {
+  // The following repositories are used to publish artifacts to.
+  repositories {
+    maven {
+      name = 'github'
+      url = uri("https://maven.pkg.github.com/cyface-de/protos")
+      credentials {
+        username = project.findProperty("gpr.user") ?: System.getenv("USERNAME")
+        password = project.findProperty("gpr.key") ?: System.getenv("PASSWORD")
+      }
+    }
+    maven {
+      name = 'local'
+      url = "file://${rootProject.buildDir}/repo"
+    }
+  }
+}
\ No newline at end of file
diff --git a/gradle.properties.template b/gradle.properties.template
new file mode 100644
index 0000000..45a31b3
--- /dev/null
+++ b/gradle.properties.template
@@ -0,0 +1,2 @@
+gpr.user=<GITHUB_USERNAME>
+gpr.key=<GITHUB_ACCESS_TOKEN>
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..e708b1c
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..442d913
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..4f906e0
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# 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
+#
+#      https://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.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..ac1b06f
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..0426832
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2021 Cyface GmbH
+ * 
+ * This file is part of the Cyface Protocol Buffer Messages.
+ *
+ * The Cyface Protocol Buffer Messages is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * The Cyface Protocol Buffer Messages is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the Cyface Protocol Buffer Messages. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+//noinspection SpellCheckingInspection
+rootProject.name = 'protos'
diff --git a/src/main/protos/de/cyface/protos/model/measurement.proto b/src/main/protos/de/cyface/protos/model/measurement.proto
new file mode 100644
index 0000000..397e36a
--- /dev/null
+++ b/src/main/protos/de/cyface/protos/model/measurement.proto
@@ -0,0 +1,443 @@
+/*
+ * Copyright (C) 2021 Cyface GmbH - All Rights Reserved
+ *
+ * Unauthorized copying of this file, via any medium is strictly prohibited
+ * Proprietary and confidential
+ */
+syntax = "proto3";
+
+/*
+ * More details on packages: https://developers.google.com/protocol-buffers/docs/proto3#packages
+ * And Style Guide Packages section: https://developers.google.com/protocol-buffers/docs/style#packages
+ */
+package de.cyface.protos.model;
+
+/*
+ * To generate own `.java` files for the top level classes/enums.
+ *
+ * More details on options: https://developers.google.com/protocol-buffers/docs/proto3#options
+ *
+ * Import messages:
+ * - In java you cannot import message types from other `.proto` files.
+ *   see https://developers.google.com/protocol-buffers/docs/proto3#importing_definitions
+ * - "Any" for arbitrary serialized messages as bytes without having their `proto` definitions
+ *   see https://developers.google.com/protocol-buffers/docs/proto3#any
+ */
+option java_multiple_files = true;
+
+/*
+ * A message type which wraps all data collected between a "start" and a "stop" lifecycle event.
+ *
+ * We are reserving field numbers 1-15 for high-frequent fields (> 10 Hz) that we might want to add later.
+ * - The `reserved` definition is not used, as "field numbers cannot be used by future users"
+ *   see https://developers.google.com/protocol-buffers/docs/proto3#updating
+ * - The following fields are not repeating: formatVersion, locationsRecords, accelerations/r./d., capturingLog
+ * - The following fields are expected less than 10 Hz: events, images, videos
+ *
+ * author Armin Schnabel
+ * Version 1.0.0
+ */
+message Measurement {
+  /*
+   * Using `uint32` as we expect the version to be positive and within the range of an `integer`.
+   * Negative numbers are encoded inefficiently in this data type, compared to `sint32`.
+   *
+   * The current format of the binary format version is `2`
+   */
+  uint32 format_version = 16;
+
+  /*
+   * Collection of geo-locations.
+   *
+   * We use a packed encoding here, so this is a non repeated field.
+   */
+  LocationRecords location_records = 17;
+  /*
+   * Collection of acceleration points.
+   *
+   * We use a packed encoding here, so this is a non repeated field.
+   */
+  Accelerations accelerations = 18;
+  /*
+   * Collection of rotation points.
+   *
+   * We use a packed encoding here, so this is a non repeated field.
+   */
+  Rotations rotations = 19;
+  /*
+   * Collection of direction points.
+   *
+   * We use a packed encoding here, so this is a non repeated field.
+   */
+  Directions directions = 20;
+  
+  /*
+   * Collection of events.
+   *
+   * We use `repeated` as we don't expect as many events as e.g. sensor points.
+   * If we decide to store high-frequent events later on we can use a field number < 16 which only requires 1 Byte.
+   */
+  repeated Event events = 21;
+
+  /*
+   * We expect a similar amount of images as e.g. locations (<= 1 Hz).
+   * But the image data is anyway very large, thus, we don't have to care too much about the field number encoding size and use `repeated` complex types.
+   * 
+   * The image files are usually of FileType `JPG` (compressed) or `DNG` (raw).
+   */
+  repeated File images = 22;
+  /*
+   * When a measurement is paused and resumed, multiple video files are collected per measurement - thus, `repeated`.
+   * 
+   * The video files are usually of FileType `MP4`.
+   */
+  repeated File videos = 23;
+  /*
+   * While capturing images we log the capturing frequencies and some more data.
+   *
+   * This field allows to attach this file which is usually a of FileType `CSV`.
+   */
+  File capturing_log = 24;
+}
+
+/*
+ * A message type which wraps all geo-locations captured for one measurement.
+ *
+ * Each field contains the ordered list of that attribute for all points.
+ * I.e. field1[4] and field2[4] belong to the same point.
+ *
+ * Reason why we don't use `repeated LocationRecord` (and the same for sensor data):
+ * - In proto3 repeated fields use the "packed" encoding by default.
+ *   A field with 0 elements is not appearing in the message.
+ *   A field with >0 elements and a "primitive numeric type" use a single key-value pair with "wire type 2(length-delimited)".
+ *   Fields with non-primitive types (like `LocationRecord` would be) encode the `key` for each repetition of `LocationRecord`.
+ *   Example: LR KV KV, LR KV ... with LR = field number of LocationRecord and KV is a key-value pair inside this record.
+ *   i.e.: LocationRecord{ts=1234567890123,lat=51012345,lon=13012345}, LocationRecord{ts=1000,lat=34,lon=54}
+ *   Bytes: 56-66 KiB (without/with elevations) for a measurement with 3600 Locations (and no sensor data)
+ * - We use a more efficient way: One LR-entry with multiple primitive `packed` fields.
+ *   Example: LR K V V V V V K V V V V V, i.e. we only have to encode the type "LocationRecord" once not for each record.
+ *   i.e: LocationRecords { ts=[1234567890123,1000,1000], lat=[51012345,34,35], lon=[13012345,54,55]}
+ *   Bytes: 32-49 KiB (without/with elevations) for a measurement with 3600 Locations (and no sensor data)
+ * - In this annotation each LR must have a ts/lat/lon/speed/accuracy or else this does not work.
+ *   Only for `elevation` we define a `Elevation` message type which can also have no value and would encoded: `E E KV` or `E KV E KV`
+ */
+message LocationRecords {
+  /*
+   * Using `uint64` as we expect the timestamps to be in order, i.e. usually only ascending.
+   * Negative numbers are encoded inefficiently in this data type, compared to `sint32`.
+   * `64bit` as the first timestamp is absolute and in milliseconds since 1970, i.e. it's not within the boundaries of `integer`.
+   *
+   * The timestamps are encoded in the offset/diff format, e.g.: 1234567890123,1000,1000,1000.
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated uint64 timestamp = 1;
+
+  /*
+   * Using `sint32` as the latitude can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   * `32bit` as the maximum expected value is the diff between -180 and +180 which is: 360_000_000 and within `integer` range.
+   *
+   * The coordinate-part is encoded in the offset/diff format, e.g.:
+   * (51.012345,13.012300),(51.012300,13.012345) => lat=[51012345,-45], lon=[13012300,45]
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated sint32 latitude = 2;
+
+  /*
+   * Using `sint32` as the latitude can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   * `32bit` as the maximum expected value is the diff between -90 and +90 which is: 180_000_000 and within `integer` range.
+   *
+   * The coordinate-part is encoded in the offset/diff format, e.g.:
+   * (51.012345,13.012300),(51.012300,13.012345) => lat=[51012345,-45], lon=[13012300,45]
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated sint32 longitude = 3;
+
+  /*
+   * Using a complex type `Elevation` for elevations as we expect some elevations to be `null`.
+   * - Due to the "collection" format of the `LocationRecords` we cannot use a `repeated sint32 elevation` field as this does not support `null` entries.
+   *
+   * We use 1-byte field numbers (1-15) for `elevation` and the `Elevation` fields as this is a repeated complex field, i.e. these numbers are encoded for each location.
+   */
+  repeated Elevation elevation = 4; 
+
+  /*
+   * The encoding should look like the following:
+   * - E 1 48000 E 1 100 E 1 -50 (scenario where all locations have elevations)
+   * - E 1 48000 E 2 1   E 1 100 (scenario where some locations have elevations)
+   * - 0 bytes                   (scenario without elevations)
+   */
+  message Elevation {
+    /*
+     * Using `sint32` as the elevation can as likely decrease as increase - using the diff/offset format here.
+     * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+     * `32bit`, i.e. we support a diff value up to ~2*10^9 cm which is ~ 20.000 km. The diff between mount everest
+     * and the dead sea is ~ [8848m;-414m] so we should be good when teleporting between dry and comfy places on earth for a while.
+     *
+     * The elevation is encoded in the offset/diff format, e.g.:
+     * 480.0m, 481.0m, 480.5m => 48000 cm, 100cm, -50cm
+     * This encodes the data more efficiently, as the `varint` encoding is used.
+     *
+     * Elevation in cm above sea level, which can also be negative (as absolute number, beside the diff-annotation used here)
+     */  
+    sint32 value = 1;
+
+    /*
+     * This field is only encoded if no `value` is set (i.e. elevation `is_null`).
+     *
+     * We cannot just have the optional "value" field as we can't differentiate between default value (0) and unset (0)
+     */
+    bool is_null = 2;
+  }
+
+  /*
+   * Using `sint32` as the accuracy can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   * `32bit`, i.e. we support a diff value up to ~2*10^9 cm which is ~ 20.000 km.
+   *
+   * The accuracy is encoded in the offset/diff format, e.g.:
+   * 8.0m, 13.0m, 12.5m => 800 cm, 500cm, -50cm
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   *
+   * Accuracy in cm. Can not be smaller than 0 (as absolute number, beside the diff-annotation used here).
+   *
+   * The likelihood of that accuracy to be correct is not stored as not all platforms provide this or provide this in different format.
+   * For some platform this is static, i.e. we can retrieve this information from the osVersion/osType field.
+   */
+  repeated sint32 accuracy = 5;
+
+  /*
+   * Using `sint32` as the speed can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   * `32bit`, i.e. we support a diff value up to ~2*10^9 cm/s which is ~ 20.000 km/s.
+   * As we capture the speed relative to the earth's rotation, we should be covering all manned aircraft, but not spacecrafts.
+   *
+   * The speed is encoded in the offset/diff format, e.g.:
+   * 10.0m/s, 11.0m, 10.5m => 1000 cm/s, 100cm, -50cm
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   *
+   * Speed in cm/s. Should not be smaller than 0 (as absolute number, beside the diff-annotation used here),
+   * but we saw on some platforms (Samsung/Android?) that negative speed is recorded, but this does not break this format.
+   */
+  repeated sint32 speed = 6;
+}
+
+/*
+ * A message type which wraps all acceleration points captured for one measurement.
+ *
+ * Each field contains the ordered list of that attribute for all points.
+ * I.e. field1[4] and field2[4] belong to the same point.
+ *
+ * Reference phone, Pixel 3a, contains this sensor: https://www.bosch-sensortec.com/products/motion-sensors/imus/bmi160/
+ * - Bosch recommends the following sensor: https://www.bosch-sensortec.com/products/motion-sensors/imus/bmi270/
+ * - the sensitivity and value ranges are the same [DAT-646]
+ * - the sensitivity is 0.004790957 i.e. ~ 1/208.73 ... which is 1÷(16384 [from datasheet] ÷9,81 [g to m/s])×8 [8 bits per byte/digit]
+ * - Thus, we choose a unit value of 0.001 m/s^2, i.e 1mm/s^2.
+ */
+message Accelerations {
+  /*
+   * Using `uint` as we expect the timestamps to be in order, i.e. usually only ascending.
+   * Negative numbers are encoded inefficiently in this data type, compared to `sint32`.
+   *
+   * The timestamps are encoded in the offset/diff format, e.g.: 1234567890123,1000,1000,1000.
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated uint64 timestamp = 1;
+
+  /*
+   * Using `sint` as the one-axial-sensor-value can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   *
+   * The axial sensor value is encoded in the offset/diff format, e.g.:
+   * (-0.009 m/s^2, +0.359 m/s^2, -4.82 m/s^2) => (-9 mm/s^2, +359 mm/s^2, -5_179 mm/s^2)
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   *
+   * The sensor value in mm/s^2, which can also be negative (as absolute number, beside the diff-annotation used here).
+   * The sensor value is rounded to the closest mm/s^2 value, "with ties rounding to positive infinity" as stated in the Java doc.
+   * 
+   * Absolute values between +-16 m/s^2 are expected, i.e. +- 32_000 mm/s^2 diff.
+   * `32 bit` i.e. we support diffs up to ~2*10^9 mm/s^2 ~ 2.000 km/s^2. We should be fine here.
+   */
+  repeated sint32 x = 2;
+  repeated sint32 y = 3;
+  repeated sint32 z = 4;
+}
+
+/*
+ * A message type which wraps all rotation points captured for one measurement.
+ *
+ * Each field contains the ordered list of that attribute for all points.
+ * I.e. field1[4] and field2[4] belong to the same point.
+ *
+ * Reference phone, Pixel 3a, contains this sensor: https://www.bosch-sensortec.com/products/motion-sensors/imus/bmi160/
+ * - Bosch recommends the following sensor: https://www.bosch-sensortec.com/products/motion-sensors/imus/bmi270/
+ * - the sensitivity and value ranges are the same [DAT-646]
+ * - the sensitivity is 0.0010652635 rad/s. (e.g. the Tinkerforge IMU uses 1/16 °/s = 0.00109083078 rad/s)
+ * - not sure how to get the sensitivity from the `262.4 LSB/°/s` from the data sheet, though
+ * - Thus, we choose a unit value of 0.001 rad/s, i.e 1 rad/1000s (which would be 3.6 rad/h, but we don't use that unit).
+ */
+message Rotations {
+  /*
+   * Using `uint` as we expect the timestamps to be in order, i.e. usually only ascending.
+   * Negative numbers are encoded inefficiently in this data type, compared to `sint32`.
+   *
+   * The timestamps are encoded in the offset/diff format, e.g.: 12345678901230,10000,10000,10000.
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated uint64 timestamp = 1;
+
+  /*
+   * Using `sint` as the one-axial-sensor-value can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   *
+   * The axial sensor value is encoded in the offset/diff format, e.g.:
+   * (+0.083 rad/s, -0.051 rad/s, +4.367 rad/s) => (83 rad/1000s, -134 rad/1000s, +4_418 rad/1000s)
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   *
+   * The sensor value in rad/1000s, which can also be negative (as absolute number, beside the diff-annotation used here).
+   * The sensor value is rounded to the closest rad/1000s value, "with ties rounding to positive infinity" as stated in the Java doc.
+   * 
+   * Absolute values between +(-?) 2000 degrees/s are expected, i.e. +- 2*34.906585 rad/s, i.e. +-69_814 rad/1000s diff.
+   * `32 bit` i.e. we support diffs up to ~2*10^9 rad/1000s ~ 2*10^6 rad/s. We should be fine here.
+   */
+  repeated sint32 x = 2;
+  repeated sint32 y = 3;
+  repeated sint32 z = 4;
+}
+
+/*
+ * A message type which wraps all direction points captured for one measurement.
+ *
+ * Each field contains the ordered list of that attribute for all points.
+ * I.e. field1[4] and field2[4] belong to the same point.
+ *
+ * Reference phone, Pixel 3a, contains this sensor: akm, AK0991X Magnetometer, Version 20012 (no good data sheet found)
+ * - Another phones use https://www.digikey.de/catalog/en/partgroup/ak09915/65408, with 1/16 resolution (same as e.g. Tinkerforge)
+ * - the sensitivity is 0.15 µT. (e.g. Tinkerforge IMU uses 1/16 µT = 0.0625 µT)
+ * - Thus, we choose a unit value of 0.01 µT, i.e 1 µT/100 (which would be 10 nT, but we don't use that unit).
+ */
+message Directions {
+  /*
+   * Using `uint` as we expect the timestamps to be in order, i.e. usually only ascending.
+   * Negative numbers are encoded inefficiently in this data type, compared to `sint32`.
+   *
+   * The timestamps are encoded in the offset/diff format, e.g.: 1234567890123,1000,1000,1000.
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   */
+  repeated uint64 timestamp = 1;
+
+  /*
+   * Using `sint` as the one-axial-sensor-value can as likely decrease as increase - using the diff/offset format here.
+   * Negative numbers are encoded more efficiently in this data type, compared to `int32`.
+   *
+   * The axial sensor value is encoded in the offset/diff format, e.g.:
+   * (+0.67 µT, -1.41 µT, +0.42 µT) => (67 µT/100, -208 µT/100, +183 µT/100)
+   * This encodes the data more efficiently, as the `varint` encoding is used.
+   *
+   * The sensor value in 1/100 µT, which can also be negative (as absolute number, beside the diff-annotation used here).
+   * The sensor value is rounded to the closest µT/100 value, "with ties rounding to positive infinity" as stated in the Java doc.
+   * The 10 nT unit does not cover travels between galaxies, at least you can't orientate by magnetic values due to the weak field there.
+   * 
+   * Absolute values between +- 4911.994 µT on Pixel 3a and +- 1300 µT on Tinkerforge are expected, i.e. +- 982_400 µT/100 diff.
+   * `32 bit` i.e. we support diffs up to ~2*10^9 µT/100 ~ 20 T so strong magnet as in the LHC/CERN are covered theoretically.
+   */
+  repeated sint32 x = 2;
+  repeated sint32 y = 3;
+  repeated sint32 z = 4;
+}
+
+/*
+ * A message type which wraps data of one event captured, such as the `start` lifecycle event or a `modality change`.
+ *
+ * We store each event separately we don't expect different event types to contain all fields.
+ * Fields like `timestamp`, `type` and `value` use a 1 Byte field number (1-15) as this field probably occurs in most events.
+ *
+ * If we do increase the frequency later on, we should also change the field number of `Measurement.events` to a 1 Byte number.
+ */
+message Event {
+  /*
+   * Using `int64` as we don't expect negative timestamps.
+   *
+   * As we don't expect as many events as e.g. locations, we don't use the offset/diff variant here.
+   */
+  uint64 timestamp = 1;
+
+  /*
+   * Enum which helps to identify different types of event and to know which event fields to expect.
+   */
+  EventType type = 2;
+
+  /*
+   * Additional information. Dependent on the `EventType`.
+   *
+   * E.g.: the new value after a `MODALITY_TYPE_CHANGE` such as `BICYCLE`.
+   * 
+   * Protobuf `strings` must always contain UTF-8 encoded (or 7-bit ASCII text), and cannot be longer than 2^32.
+   */
+  string value = 3;
+
+  /*
+   * Enum which helps to identify different types of event and to know which event fields to expect.
+   *
+   * The order of the enum definitions are equal to the order before the `protobuf` implementation.
+   *
+   * The 1st element must be 0. Following the Style Guide it's named enum_name_UNSPECIFIED.
+   * For more details and options like "alias" see: https://developers.google.com/protocol-buffers/docs/proto3#enum
+  */
+  enum EventType {
+    /*
+     * Reserving 1-15 for events which we might want to add later which occur very frequently
+     *
+     * Our current events like lifecycle-button-presses or modality-type-changes only occur rarely
+     * An example for high-frequent event types could be e.g. debugging/crash events
+     */
+    EVENT_TYPE_UNSPECIFIED = 0; // Default value
+    LIFECYCLE_START = 16;
+    LIFECYCLE_STOP = 17;
+    LIFECYCLE_RESUME = 18;
+    LIFECYCLE_PAUSE = 19;
+    MODALITY_TYPE_CHANGE = 20;
+  }
+}
+
+/*
+ * Message type which wraps a file which is collected during one measurement.
+ *
+ * Reserving 1 Byte field numbers 1-15 for `repeated` complex type field which we might want to add later.
+ */
+message File {
+  /*
+   * The timestamp representing the "time of capturing" of the data inside the file.
+   *
+   * `uint64` used as we don't expect negative timestamps.
+   * As files are usually quite larges, we don't same the timestamp in the offset/diff format.
+   */
+  uint64 timestamp = 16;
+
+  /*
+   * The type of the file represented by the binary data.
+   */
+  FileType type = 17;
+
+  /*
+   * The binary data of the file.
+   *
+   * "Any arbitrary sequence of bytes no longer than 2^32" https://developers.google.com/protocol-buffers/docs/proto3#scalar
+   */
+  bytes bytes = 18;
+
+  /*
+   * The type of the file represented by the binary data.
+   *
+   * The 1st element must be 0. Following the Style Guide it's named enum_name_UNSPECIFIED.
+   * For more details and options like "alias" see: https://developers.google.com/protocol-buffers/docs/proto3#enum
+   */
+  enum FileType {
+    FILE_TYPE_UNSPECIFIED = 0; // Default value
+    JPG = 1; // Compressed image, interpreted as images captured during the measurement, e.g. from Android
+    DNG = 2; // Raw image, interpreted as images captured during the measurement, e.g. from Android
+    MP4 = 3; // Video, interpreted as a video captured during the measurement, e.g. from Android
+    CSV = 4; // CSV used e.g. to protocol the image capturing on Android
+  }
+}
\ No newline at end of file
diff --git a/src/test/java/de/cyface/protos/model/MeasurementOrBuilderTest.java b/src/test/java/de/cyface/protos/model/MeasurementOrBuilderTest.java
new file mode 100644
index 0000000..cddbaee
--- /dev/null
+++ b/src/test/java/de/cyface/protos/model/MeasurementOrBuilderTest.java
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2021 Cyface GmbH - All Rights Reserved
+ *
+ * Unauthorized copying of this file, via any medium is strictly prohibited
+ * Proprietary and confidential
+ */
+package de.cyface.protos.model;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.lessThan;
+
+import org.apache.commons.lang3.Validate;
+import org.junit.jupiter.api.Test;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+
+public class MeasurementOrBuilderTest {
+
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     */
+    private static final Integer SERIALIZED_SIZE_FORMAT_VERSION_ONLY = 3;
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     * - one location without elevation (2+8+6+6+1+4+4=31 Byte)
+     */
+    private static final Integer SERIALIZED_SIZE_ONE_LOCATION_WITHOUT_ELEVATION = 34;
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     * - two locations without elevation (31 Byte for the first, 0+2+2+2+1+2+2=11 Byte for the second)
+     */
+    private static final Integer SERIALIZED_SIZE_TWO_LOCATIONS_WITHOUT_ELEVATION = 44;
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     * - two locations without elevation (42 Bytes)
+     * - 2+2 Byte for the first, empty Elevation (isNull=true)
+     * - 2+4 Bytes for the second, absolute Elevation value
+     */
+    private static final Integer SERIALIZED_SIZE_TWO_LOCATIONS_WITH_ONE_ELEVATION = 54;
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     * - first location without elevations (31 Bytes)
+     * - subsequent locations without elevations (+ 3599 * ~9.2 Bytes = ~33_110)
+     */
+    private static final int[] SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITHOUT_ELEVATIONS = new int[] {32_000, 34_000};
+    /**
+     * Number of bytes of a serialized measurement (1 Byte) which contains:
+     * - the format version (2 Bytes)
+     * - first location without elevations (31 Bytes)
+     * - subsequent locations without elevations (+ 3599 * ~9 Bytes = 33_110)
+     * - 2+4 Bytes for the first, absolute Elevation value (6 Bytes)
+     * - 2+2 Bytes for the second, relative Elevation value (+ 3599 * ~4.2 Bytes = ~15_115)
+     */
+    private static final int[] SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITH_ELEVATIONS = new int[] {48_000, 49_000};
+
+    @Test
+    void test_serializedSize_forEmptyMeasurement() throws InvalidProtocolBufferException {
+        // Arrange
+        final var measurement = Measurement.newBuilder().setFormatVersion(2).build();
+        Validate.isTrue(measurement.isInitialized());
+
+        // Act
+        final var serialized = measurement.toByteArray();
+
+        // Assert
+        assertThat(serialized.length, is(equalTo(SERIALIZED_SIZE_FORMAT_VERSION_ONLY)));
+        final var deserialized = Measurement.parseFrom(serialized);
+        assertThat(deserialized.getFormatVersion(), is(equalTo(measurement.getFormatVersion())));
+    }
+
+    @Test
+    void test_serializedSize_forOneLocation_withoutElevation() throws InvalidProtocolBufferException {
+        // Arrange
+        // noinspection SpellCheckingInspection
+        final var locations = LocationRecords.newBuilder()
+                .addTimestamp(1621582427000L)
+                .addLatitude(51_064590) // At "Hafenbrücke" in Dresden "Alberthafen"
+                .addLongitude(13_699045)
+                .addAccuracy(800) // 8 m
+                .addSpeed(1000) // 10 m/s
+                .build();
+        final var measurement = Measurement.newBuilder()
+                .setFormatVersion(2)
+                .setLocationRecords(locations)
+                .build();
+        Validate.isTrue(measurement.isInitialized());
+
+        // Act
+        final var serialized = measurement.toByteArray();
+
+        // Assert
+        assertThat(serialized.length, is(equalTo(SERIALIZED_SIZE_ONE_LOCATION_WITHOUT_ELEVATION)));
+        final var deserialized = Measurement.parseFrom(serialized);
+        assertThat(deserialized.getFormatVersion(), is(equalTo(measurement.getFormatVersion())));
+    }
+
+    @Test
+    void test_serializedSize_forTwoLocations_withoutElevations() throws InvalidProtocolBufferException {
+        // Arrange
+        // noinspection SpellCheckingInspection
+        final var locations = LocationRecords.newBuilder()
+                .addTimestamp(1621582427000L)
+                .addTimestamp(1000L) // 1 second later
+                .addLatitude(51_064590) // Crossing "Hafenbrücke" in Dresden "Alberthafen"
+                .addLatitude(190)
+                .addLongitude(13_699045)
+                .addLongitude(-700)
+                .addAccuracy(800) // 8 m
+                .addAccuracy(-300) // 5 m
+                .addSpeed(1000) // 10 m/s
+                .addSpeed(-1000) // 0 m/s
+                .build();
+        final var measurement = Measurement.newBuilder()
+                .setFormatVersion(2)
+                .setLocationRecords(locations)
+                .build();
+        Validate.isTrue(measurement.isInitialized());
+
+        // Act
+        final var serialized = measurement.toByteArray();
+
+        // Assert
+        assertThat(serialized.length, is(equalTo(SERIALIZED_SIZE_TWO_LOCATIONS_WITHOUT_ELEVATION)));
+        final var deserialized = Measurement.parseFrom(serialized);
+        assertThat(deserialized.getFormatVersion(), is(equalTo(measurement.getFormatVersion())));
+        assertThat(deserialized.getLocationRecords().getElevationCount(), is(equalTo(0)));
+    }
+
+    @Test
+    void test_serializedSize_forTwoLocations_withOneElevations() throws InvalidProtocolBufferException {
+        // Arrange
+        // noinspection SpellCheckingInspection
+        final var locations = LocationRecords.newBuilder()
+                .addTimestamp(1621582427000L)
+                .addTimestamp(1000L) // 1 second later
+                .addLatitude(51_064590) // Crossing "Hafenbrücke" in Dresden "Alberthafen"
+                .addLatitude(190)
+                .addLongitude(13_699045)
+                .addLongitude(-700)
+                .addAccuracy(800) // 8 m
+                .addAccuracy(-300) // 5 m
+                .addSpeed(1000) // 10 m/s
+                .addSpeed(-1000) // 0 m/s
+                // (!) If no elevation is present for some locations only, always set `isNull` or else elevation is 0!
+                .addElevation(LocationRecords.Elevation.newBuilder().setIsNull(true).build()) // no elevation value
+                .addElevation(LocationRecords.Elevation.newBuilder().setValue(480_00).build()) // 480 m
+                .build();
+        final var measurement = Measurement.newBuilder()
+                .setFormatVersion(2)
+                .setLocationRecords(locations)
+                .build();
+        Validate.isTrue(measurement.isInitialized());
+
+        // Act
+        final var serialized = measurement.toByteArray();
+
+        // Assert
+        assertThat(serialized.length, is(equalTo(SERIALIZED_SIZE_TWO_LOCATIONS_WITH_ONE_ELEVATION)));
+        final var deserialized = Measurement.parseFrom(serialized);
+        assertThat(deserialized.getFormatVersion(), is(equalTo(measurement.getFormatVersion())));
+        assertThat(deserialized.getLocationRecords().getElevationCount(), is(equalTo(2)));
+        assertThat(deserialized.getLocationRecords().getElevation(0).getIsNull(), is(equalTo(true)));
+        assertThat(deserialized.getLocationRecords().getElevation(1).getIsNull(), is(equalTo(false)));
+        assertThat(deserialized.getLocationRecords().getElevation(1).getValue(), is(equalTo(480_00)));
+    }
+
+    @Test
+    void test_serializedSize_one3600Locations() throws InvalidProtocolBufferException {
+        // Arrange
+        final var locationsWithoutElevations = generateLocations(3600, false);
+        final var locationsWithElevations = generateLocations(3600, true);
+        final var measurementWithoutElevations = Measurement.newBuilder()
+                .setFormatVersion(2)
+                .setLocationRecords(locationsWithoutElevations)
+                .build();
+        final var measurementWithElevations = Measurement.newBuilder()
+                .setFormatVersion(2)
+                .setLocationRecords(locationsWithElevations)
+                .build();
+        Validate.isTrue(measurementWithoutElevations.isInitialized());
+        Validate.isTrue(measurementWithElevations.isInitialized());
+
+        // Act
+        final var serializedWithoutElevations = measurementWithoutElevations.toByteArray();
+        final var serializedWithElevations = measurementWithElevations.toByteArray();
+
+        // Assert (byte range tested with 100.000 random generated measurements)
+        assertThat(serializedWithoutElevations.length,
+                is(greaterThan(SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITHOUT_ELEVATIONS[0])));
+        assertThat(serializedWithoutElevations.length,
+                is(lessThan(SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITHOUT_ELEVATIONS[1])));
+        assertThat(serializedWithElevations.length,
+                is(greaterThan(SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITH_ELEVATIONS[0])));
+        assertThat(serializedWithElevations.length,
+                is(lessThan(SERIALIZED_SIZE_RANGE_3600_LOCATIONS_WITH_ELEVATIONS[1])));
+        final var deserialized = Measurement.parseFrom(serializedWithoutElevations);
+        assertThat(deserialized.getFormatVersion(), is(equalTo(measurementWithoutElevations.getFormatVersion())));
+    }
+
+    @SuppressWarnings("SameParameterValue")
+    private LocationRecords generateLocations(@SuppressWarnings("SameParameterValue") final int amount,
+            final boolean withElevations) {
+        final var builder = LocationRecords.newBuilder();
+        for (var i = 0; i < amount; i++) {
+            if (i == 0) {
+                // noinspection SpellCheckingInspection
+                builder.addTimestamp(1621582427000L)
+                        .addLatitude(51_064590) // Crossing "Hafenbrücke" in Dresden "Alberthafen"
+                        .addLongitude(13_699045)
+                        .addAccuracy(800) // 8 m
+                        .addSpeed(1000); // 10 m/s
+                if (withElevations) {
+                    builder.addElevation(LocationRecords.Elevation.newBuilder().setValue(48000).build()); // 480 m
+                }
+            } else {
+                final var random = (int)(Math.random() * 20);
+                final var randomPlusMinus = random - 10;
+                builder.addTimestamp(1000L) // 1 second later
+                        .addLatitude(randomPlusMinus * 10)
+                        .addLongitude(randomPlusMinus * 100)
+                        .addAccuracy(randomPlusMinus * 100)
+                        .addSpeed(randomPlusMinus * 100);
+                if (withElevations) {
+                    builder.addElevation(LocationRecords.Elevation.newBuilder().setValue(randomPlusMinus * 10).build());
+                }
+            }
+        }
+        return builder.build();
+    }
+}