diff --git a/ogn/backend/__init__.py b/ogn/backend/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/ogn/backend/liveglidernet.py b/ogn/backend/liveglidernet.py
new file mode 100644
index 0000000..e4d4e11
--- /dev/null
+++ b/ogn/backend/liveglidernet.py
@@ -0,0 +1,93 @@
+from datetime import datetime, timedelta, date
+import os
+
+from sqlalchemy import func, and_, between, case, null
+
+from ogn.model import AircraftBeacon, DeviceInfo, Device, Receiver
+
+
+def rec(session):
+    last_10_minutes = datetime.utcnow() - timedelta(minutes=10)
+    receiver_query = session.query(Receiver,
+                                   case([(Receiver.lastseen > last_10_minutes, True)],
+                                        else_=False).label('is_online')) \
+        .order_by(Receiver.name)
+
+    lines = list()
+    lines.append('<?xml version="1.0" encoding="UTF-8"?>')
+    lines.append('<markers>')
+    lines.append('<m e="0"/>')
+    for [receiver, is_online] in receiver_query.all():
+        lines.append('<m a="{0}" b="{1:.7f}" c="{2:.7f}" d="{3:1d}"/>'
+                     .format(receiver.name, receiver.location.latitude, receiver.location.longitude, is_online))
+
+    lines.append('</markers>')
+    xml = '\n'.join(lines)
+
+    return xml
+
+
+def lxml(session, show_offline=False, lat_max=90, lat_min=-90, lon_max=180, lon_min=-180):
+
+    if show_offline:
+        observation_start = date.today()
+    else:
+        observation_start = datetime.utcnow() - timedelta(minutes=5)
+
+    position_query = session.query(Device, AircraftBeacon, DeviceInfo) \
+        .filter(and_(between(func.ST_Y(AircraftBeacon.location_wkt), lat_min, lat_max),
+                     between(func.ST_X(AircraftBeacon.location_wkt), lon_min, lon_max))) \
+        .filter(Device.lastseen > observation_start) \
+        .filter(Device.last_position_beacon_id == AircraftBeacon.id) \
+        .outerjoin(DeviceInfo, DeviceInfo.device_id == Device.id)
+
+    lines = list()
+    lines.append('<?xml version="1.0" encoding="UTF-8"?>')
+    lines.append('<markers>')
+
+    for [aircraft_beacon, device_info] in position_query.all():
+        if device_info and (not device_info.tracked or not device_info.identified):
+            continue
+
+        code = encode(aircraft_beacon.address)
+
+        if device_info is None:
+            competition = ('_' + code[-2:]).lower()
+            registration = code
+            address = 0
+        else:
+            if not device_info.competition:
+                competition = device_info.registration[-2:]
+            else:
+                competition = device_info.competition
+
+            if not device_info.registration:
+                registration = '???'
+            else:
+                registration = device_info.registration
+
+            address = device_info.address
+
+        elapsed_time = datetime.utcnow() - aircraft_beacon.timestamp
+        elapsed_seconds = int(elapsed_time.total_seconds())
+
+        lines.append('<m a="{0:.7f},{1:.7f},{2},{3},{4},{5},{6},{7},{8},{9},{10},{11},{12},{13}"/>'
+                     .format(aircraft_beacon.location.latitude,
+                             aircraft_beacon.location.longitude,
+                             competition,
+                             registration,
+                             aircraft_beacon.altitude,
+                             utc_to_local(aircraft_beacon.timestamp).strftime("%H:%M:%S"),
+                             elapsed_seconds,
+                             int(aircraft_beacon.track),
+                             int(aircraft_beacon.ground_speed),
+                             int(aircraft_beacon.climb_rate*10)/10,
+                             aircraft_beacon.aircraft_type,
+                             aircraft_beacon.receiver_name,
+                             address,
+                             code))
+
+    lines.append('</markers>')
+    xml = '\n'.join(lines)
+
+    return xml
diff --git a/ogn/backend/ognrange.py b/ogn/backend/ognrange.py
new file mode 100644
index 0000000..48c86ed
--- /dev/null
+++ b/ogn/backend/ognrange.py
@@ -0,0 +1,35 @@
+import json
+from datetime import datetime, timedelta
+
+from sqlalchemy import func, case
+from sqlalchemy.sql.expression import label
+from ogn.model import Receiver
+
+
+def alchemyencoder(obj):
+    import decimal
+    from datetime import datetime
+    """JSON encoder function for SQLAlchemy special classes."""
+    if isinstance(obj, datetime):
+        return obj.strftime('%Y-%m-%d %H:%M')
+    elif isinstance(obj, decimal.Decimal):
+        return float(obj)
+
+
+def stations2_filtered_pl(session):
+    last_10_minutes = datetime.utcnow() - timedelta(minutes=10)
+
+    query = session.query(
+        Receiver.name.label('s'),
+        label('lt', func.round(func.ST_Y(Receiver.location_wkt)*10000)/10000),
+        label('lg', func.round(func.ST_X(Receiver.location_wkt)*10000)/10000),
+        case([(Receiver.lastseen > last_10_minutes, "U")],
+            else_="D").label('u'),
+        Receiver.lastseen.label('ut'),
+        label('v', Receiver.version + '.' + Receiver.platform)) \
+        .order_by(Receiver.lastseen)
+
+    res = session.execute(query)
+    stations = json.dumps({"stations": [dict(r) for r in res]}, default=alchemyencoder)
+
+    return stations
diff --git a/setup.py b/setup.py
index 1c6ad32..79be068 100644
--- a/setup.py
+++ b/setup.py
@@ -47,7 +47,8 @@ setup(
         'dev': [
             'nose==1.3.7',
             'coveralls==1.2',
-            'flake8==3.5.0'
+            'flake8==3.5.0',
+            'xmlunittest==0.4.0'
         ]
     },
     zip_safe=False
diff --git a/tests/backend/test_backends.py b/tests/backend/test_backends.py
new file mode 100644
index 0000000..d3ed434
--- /dev/null
+++ b/tests/backend/test_backends.py
@@ -0,0 +1,131 @@
+import unittest
+from unittest import mock
+import os
+from datetime import datetime
+
+from xmlunittest import XmlTestMixin
+
+from ogn.model import Receiver, Device
+
+from ogn.backend.liveglidernet import rec, lxml
+from ogn.backend.ognrange import stations2_filtered_pl
+
+
+class TestDB(unittest.TestCase, XmlTestMixin):
+    session = None
+    engine = None
+    app = None
+
+    def setUp(self):
+        os.environ['OGN_CONFIG_MODULE'] = 'config.test'
+        from ogn.commands.dbutils import engine, session
+        self.session = session
+        self.engine = engine
+
+        from ogn.commands.database import init
+        init()
+
+        # Prepare Beacons
+        self.r01 = Receiver(name='Koenigsdf', location_wkt='0101000020E610000061E8FED7A6EE26407F20661C10EA4740', lastseen='2017-12-20 10:00:00', altitude=601, version='0.2.5', platform='ARM')
+        self.r02 = Receiver(name='Bene', location_wkt='0101000020E6100000D5E76A2BF6C72640D4063A6DA0DB4740', lastseen='2017-12-20 09:45:00', altitude=609, version='0.2.7', platform='x64')
+        self.r03 = Receiver(name='Ohlstadt', location_wkt='0101000020E6100000057E678EBF772640A142883E32D44740', lastseen='2017-12-20 10:05:00', altitude=655, version='0.2.6', platform='ARM')
+
+        self.d01 = Device(address='DD4711')
+        self.d02 = Device(address='DD0815')
+
+        session.add(self.r01)
+        session.add(self.r02)
+        session.add(self.r03)
+
+        session.add(self.d01)
+        session.add(self.d02)
+        session.commit()
+
+    def tearDown(self):
+        session = self.session
+        session.execute("DELETE FROM receiver")
+        session.commit()
+
+    @mock.patch('ogn.backend.liveglidernet.datetime')
+    def test_rec(self, datetime_mock):
+        session = self.session
+
+        datetime_mock.utcnow.return_value = datetime(2017, 12, 20, 10, 0)
+
+        data = rec(session).encode(encoding='utf-8')
+
+        # Check the document
+        root = self.assertXmlDocument(data)
+        self.assertXmlNode(root, tag='markers')
+        self.assertXpathsOnlyOne(root, ('./m[@a="Koenigsdf"]', './m[@a="Bene"]', './m[@a="Ohlstadt"]'))
+
+        expected = """<?xml version="1.0" encoding="UTF-8"?>
+        <markers>
+            <m e="0"/>
+            <m a="Bene" b="47.7158333" c="11.3905500" d="0"/>
+            <m a="Koenigsdf" b="47.8286167" c="11.4661167" d="1"/>
+            <m a="Ohlstadt" b="47.6577833" c="11.2338833" d="1"/>
+        </markers>
+        """.encode(encoding='utf-8')
+
+        # Check the complete document
+        self.assertXmlEquivalentOutputs(data, expected)
+
+        print(data)
+
+    @unittest.skip("not finished yet")
+    @mock.patch('ogn.backend.liveglidernet.datetime')
+    def test_lxml(self, datetime_mock):
+        session = self.session
+
+        datetime_mock.utcnow.return_value = datetime(2017, 12, 20, 10, 0)
+
+        data = lxml(session).encode(encoding='utf-8')
+
+        # Check the document
+        root = self.assertXmlDocument(data)
+        self.assertXmlNode(root, tag='markers')
+        self.assertXpathsOnlyOne(root, ('./m[@a="Koenigsdf"]', './m[@a="Bene"]', './m[@a="Ohlstadt"]'))
+
+        print(data)
+
+    @mock.patch('ogn.backend.ognrange.datetime')
+    def test_stations2_filtered_pl(self, datetime_mock):
+        session = self.session
+
+        datetime_mock.utcnow.return_value = datetime(2017, 12, 20, 10, 0)
+
+        import json
+
+        result = stations2_filtered_pl(session)
+        print(result)
+
+        data = json.loads(result)
+
+        stations = data["stations"]
+        self.assertEqual(len(stations), 3)
+        s1 = stations[0]
+        s2 = stations[1]
+        s3 = stations[2]
+
+        self.assertEqual(s1["s"], 'Bene')
+        self.assertEqual(s1["lt"], 47.7158)
+        self.assertEqual(s1["lg"], 11.3906)
+        self.assertEqual(s1["u"], "D")  # Down, because last beacon > 10min. ago
+        self.assertEqual(s1["ut"], "2017-12-20 09:45")
+        # self.assertEqual(s1["b"], 0)
+        self.assertEqual(s1["v"], "0.2.7.x64")
+
+        self.assertEqual(s2["s"], 'Koenigsdf')
+        self.assertEqual(s2["lt"], 47.8286)
+        self.assertEqual(s2["lg"], 11.4661)
+        self.assertEqual(s2["u"], "U")
+        self.assertEqual(s2["ut"], "2017-12-20 10:00")
+        # self.assertEqual(s2["b"], 0)
+        self.assertEqual(s2["v"], "0.2.5.ARM")
+
+        self.assertEqual(s3["s"], 'Ohlstadt')
+
+
+if __name__ == '__main__':
+    unittest.main()