diff --git a/pyproject.toml b/pyproject.toml
index 0fbc98b..8632d7c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,6 +9,7 @@ dependencies = [
     "sounddevice",
     "aioconsole",
     "quart == 0.20.0",
+    "pydantic"
 ]
 
 [project.optional-dependencies]
diff --git a/src/auracast/auracast_config.py b/src/auracast/auracast_config.py
index 63bc690..ad5ac03 100644
--- a/src/auracast/auracast_config.py
+++ b/src/auracast/auracast_config.py
@@ -1,40 +1,39 @@
-from bumble import hci
-from bumble.profiles import bap
-from dataclasses import dataclass
+from pydantic import BaseModel
 
-# Define some base dataclasses to hold the relevant parameters
-@dataclass
-class AuracastQoSConfig:
+# Define some base to hold the relevant parameters
+class AuracastQoSConfig(BaseModel):
+    iso_int_multiple_10ms: int
+    number_of_retransmissions: int
+    max_transport_latency_ms: int
+
+class AuracastQosHigh(AuracastQoSConfig):
     iso_int_multiple_10ms: int = 1
     number_of_retransmissions:int = 4 #4
     max_transport_latency_ms:int = 43 #varies from the default value in bumble (was 65)
 
-qos_config_mono_high_rel = AuracastQoSConfig() #highest rel + lowest latency
-qos_config_mono_medium_rel = AuracastQoSConfig( 
-    iso_int_multiple_10ms = 2,
-    number_of_retransmissions = 3,
-    max_transport_latency_ms = 65
-)
-qos_config_mono_low_rel = AuracastQoSConfig( #highest latency
-    iso_int_multiple_10ms = 3,
-    number_of_retransmissions = 2,
-    max_transport_latency_ms = 65
-)
+class AuracastQosMid(AuracastQoSConfig):
+    iso_int_multiple_10ms: int = 2
+    number_of_retransmissions:int = 3
+    max_transport_latency_ms:int = 65
 
-@dataclass
-class AuracastGlobalConfig:
-    qos_config: AuracastQoSConfig
+class AuracastQosLow(AuracastQoSConfig):
+    iso_int_multiple_10ms: int = 3
+    number_of_retransmissions:int = 2 #4
+    max_transport_latency_ms:int = 65 #varies from the default value in bumble (was 65)
+
+
+class AuracastGlobalConfig(BaseModel):
+    qos_config: AuracastQoSConfig =  AuracastQosHigh()
     debug: bool = False
     device_name: str = 'Auracaster'
     transport: str = ''
-    auracast_device_address: hci.Address = hci.Address('F0:F1:F2:F3:F4:F5')
+    auracast_device_address: str = 'F0:F1:F2:F3:F4:F5'
     auracast_sampling_rate_hz: int = 16000
     octets_per_frame: int = 40 #48kbps@24kHz # bitrate = octets_per_frame * 8 / frame len
     frame_duration_us: int = 10000
     presentation_delay_us: int = 40000
-    manufacturer_data: tuple[int, bytes] = None
+    manufacturer_data: tuple[int, bytes] |None = None # TODO:pydantic does not support bytes serialization
 
-global_base_config = AuracastGlobalConfig(qos_config=AuracastQoSConfig())
 
 # "Audio input. "
 # "'device' -> use the host's default sound input device, "
@@ -42,13 +41,10 @@ global_base_config = AuracastGlobalConfig(qos_config=AuracastQoSConfig())
 # "(specify 'device:?' to get a list of available sound input devices), "
 # "'stdin' -> receive audio from stdin as int16 PCM, "
 # "'file:<filename> -> read audio from a .wav or raw int16 PCM file. "
-
-
-@dataclass
-class AuracastBigConfig:
-    id: int = 123456,
-    random_address: hci.Address = hci.Address('F1:F1:F2:F3:F4:F5')
-    code: str = None # Broadcast_Code – a 16-octet parameter provided by the Host
+class AuracastBigConfig(BaseModel):
+    id: int = 123456
+    random_address: str = 'F1:F1:F2:F3:F4:F5'
+    code: str | None = None # Broadcast_Code – a 16-octet parameter provided by the Host
     language: str = 'eng' # See: https://en.wikipedia.org/wiki/List_of_ISO_639_language_codes
     name: str = 'Broadcast0'
     program_info: str = 'Some Announcements'
@@ -58,49 +54,45 @@ class AuracastBigConfig:
     precode_wav: bool = False
     iso_que_len: int = 64
 
+class AuracastBigConfigDe(AuracastBigConfig):
+    id: int = 12
+    random_address: str = 'F1:F1:F2:F3:F4:F5'
+    name: str = 'Broadcast0'
+    language: str ='deu'
+    program_info: str = 'Announcements German'
+    audio_source: str = 'file:./testdata/announcement_de.wav'
 
-# Instanciate some example configurations
-broadcast_de = AuracastBigConfig(
-    id=12,
-    random_address=hci.Address('F1:F1:F2:F3:F4:F5'),
-    name = 'Broadcast0',
-    language='deu',
-    program_info = 'Announcements German',
-    audio_source = 'file:./testdata/announcement_de.wav',
-)
+class AuracastBigConfigEn(AuracastBigConfig):
+    id: int = 123
+    random_address: str = 'F2:F1:F2:F3:F4:F5'
+    name: str  = 'Broadcast1'
+    language: str ='eng'
+    program_info: str  = 'Announcements English'
+    audio_source: str  = 'file:./testdata/announcement_en.wav'
 
-broadcast_en = AuracastBigConfig(
-    id=123,
-    random_address=hci.Address('F2:F1:F2:F3:F4:F5'),
-    name = 'Broadcast1',
-    language='eng',
-    program_info = 'Announcements English',
-    audio_source = 'file:./testdata/announcement_en.wav',
-)
+class AuracastBigConfigFr(AuracastBigConfig):
+    id: int = 1234
+    random_address: str = 'F3:F1:F2:F3:F4:F5'
+    name: str  = 'Broadcast2'
+    language: str ='fra'
+    program_info: str  = 'Announcements French'
+    audio_source: str  = 'file:./testdata/announcement_fr.wav'
 
-broadcast_fr = AuracastBigConfig(
-    id=1234,
-    random_address=hci.Address('F3:F1:F2:F3:F4:F5'),
-    name = 'Broadcast2',
-    language='fra',
-    program_info = 'Announcements French',
-    audio_source = 'file:./testdata/announcement_fr.wav',
-)
+class AuracastBigConfigEs(AuracastBigConfig):
+    id: int =12345
+    random_address: str = 'F4:F1:F2:F3:F4:F5'
+    name: str  = 'Broadcast3'
+    language: str ='spa'
+    program_info: str  = 'Announcements Spanish'
+    audio_source: str  = 'file:./testdata/announcement_es.wav'
 
-broadcast_es = AuracastBigConfig(
-    id=12345,
-    random_address=hci.Address('F4:F1:F2:F3:F4:F5'),
-    name = 'Broadcast3',
-    language='spa',
-    program_info = 'Announcements Spanish',
-    audio_source = 'file:./testdata/announcement_es.wav',
-)
+class AuracastBigConfigIt(AuracastBigConfig):
+    id: int =1234567
+    random_address: str = 'F5:F1:F2:F3:F4:F5'
+    name: str  = 'Broadcast4'
+    language: str ='ita'
+    program_info: str  = 'Announcements Italian'
+    audio_source: str  = 'file:./testdata/announcement_it.wav'
 
-broadcast_it = AuracastBigConfig(
-    id=123456,
-    random_address=hci.Address('F5:F1:F2:F3:F4:F5'),
-    name = 'Broadcast4',
-    language='ita',
-    program_info = 'Announcements Italian',
-    audio_source = 'file:./testdata/announcement_it.wav',
-)
\ No newline at end of file
+
+# TODO: could be best to merge all in just one CONFIG class and give every language an enable parameter
\ No newline at end of file
diff --git a/src/auracast/multicast.py b/src/auracast/multicast.py
index d1ce5de..67c041c 100644
--- a/src/auracast/multicast.py
+++ b/src/auracast/multicast.py
@@ -108,7 +108,7 @@ async def create_device(config: auracast_config.AuracastGlobalConfig) -> AsyncGe
     ):
         device_config = bumble.device.DeviceConfiguration(
             name=config.device_name,
-            address=config.auracast_device_address,
+            address= hci.Address(config.auracast_device_address),
             keystore='JsonKeyStore',
             #le_simultaneous_enabled=True #TODO: What is this doing ?
         )
@@ -201,7 +201,7 @@ async def init_broadcast(
     )
         bigs[f'big{i}']['broadcast_audio_announcement'] = bap.BroadcastAudioAnnouncement(conf.id)
         advertising_set = await device.create_advertising_set(
-            random_address=conf.random_address,
+            random_address=hci.Address(conf.random_address),
             advertising_parameters=bumble.device.AdvertisingParameters(
                 advertising_event_properties=bumble.device.AdvertisingEventProperties(
                     is_connectable=False
@@ -496,18 +496,15 @@ async def broadcast(global_conf: auracast_config.AuracastGlobalConfig, big_conf:
 if __name__ == "__main__":
     import os
     
-    if os.environ['LOG_LEVEL']:
-        log_level = getattr(logging, os.environ['LOG_LEVEL'])
-    else:
-        log_level = logging.DEBUG
-    log_level = os.environ['LOG_LEVEL']
-    logging.basicConfig(
-        level=log_level,
+    logging.basicConfig( #export LOG_LEVEL=INFO
+        level=os.environ.get('LOG_LEVEL', logging.DEBUG),
         format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
     )
     os.chdir(os.path.dirname(__file__))
 
-    global_conf = auracast_config.global_base_config
+    global_conf = auracast_config.AuracastGlobalConfig(
+        qos_config=auracast_config.AuracastQosHigh()
+    )
 
     #global_conf.transport='serial:/dev/serial/by-id/usb-ZEPHYR_Zephyr_HCI_UART_sample_81BD14B8D71B5662-if00,1000000,rtscts' # transport for nrf52 dongle
 
@@ -521,15 +518,13 @@ if __name__ == "__main__":
 
 
     # TODO: How can we use other iso interval than 10ms ?(medium or low rel) ? - nrf53audio receiver repports I2S tx underrun
-    #global_conf.qos_config = auracast_config.qos_config_mono_medium_rel
-    global_conf.qos_config = auracast_config.qos_config_mono_high_rel
 
     bigs = [
-        auracast_config.broadcast_de,
-        auracast_config.broadcast_en,
-        auracast_config.broadcast_fr,
-        #auracast_config.broadcast_es,
-        #auracast_config.broadcast_it,
+        auracast_config.AuracastBigConfigDe(),
+        auracast_config.AuracastBigConfigEn(),
+        auracast_config.AuracastBigConfigFr(),
+        #auracast_config.AuracastBigConfigEs(),
+        #auracast_config.AuracastBigConfigIt(),
         ]
     for big in bigs: # TODO: encrypted streams are not working
         #big.code = 'ff'*16 # returns hci/HCI_ENCRYPTION_MODE_NOT_ACCEPTABLE_ERROR
diff --git a/src/auracast/multicast_control_client.py b/src/auracast/multicast_client.py
similarity index 100%
rename from src/auracast/multicast_control_client.py
rename to src/auracast/multicast_client.py
diff --git a/src/auracast/multicast_control.py b/src/auracast/multicast_control.py
index 8bc3e4d..094268e 100644
--- a/src/auracast/multicast_control.py
+++ b/src/auracast/multicast_control.py
@@ -113,19 +113,24 @@ async def command_line_ui(caster: Multicaster):
             print("Invalid command.")
 
 async def main():
+    import os
+    
     logging.basicConfig(
-        level=logging.DEBUG,
+        level=os.environ.get('LOG_LEVEL', logging.DEBUG),
         format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
     )
+    os.chdir(os.path.dirname(__file__))
 
-    global_conf = auracast_config.global_base_config
+    global_conf = auracast_config.AuracastGlobalConfig(
+        qos_config=auracast_config.AuracastQosHigh()
+    )
     #global_conf.transport='serial:/dev/serial/by-id/usb-SEGGER_J-Link_001057705357-if02,1000000,rtscts' # transport for nrf54l15dk
     global_conf.transport='serial:/dev/serial/by-id/usb-ZEPHYR_Zephyr_HCI_UART_sample_81BD14B8D71B5662-if00,115200,rtscts' #nrf52dongle hci_uart usb cdc
 
     big_conf = [
-        auracast_config.broadcast_de,
-        auracast_config.broadcast_en,
-        auracast_config.broadcast_fr,
+        auracast_config.AuracastBigConfigDe(),
+        auracast_config.AuracastBigConfigEn(),
+        auracast_config.AuracastBigConfigFr(),
         #auracast_config.broadcast_es,
         #auracast_config.broadcast_it,
         ]
diff --git a/src/auracast/multicast_server.py b/src/auracast/multicast_server.py
index 05849ee..866b5c6 100644
--- a/src/auracast/multicast_server.py
+++ b/src/auracast/multicast_server.py
@@ -11,9 +11,9 @@ global_conf = auracast_config.global_base_config
 global_conf.transport='serial:/dev/serial/by-id/usb-ZEPHYR_Zephyr_HCI_UART_sample_81BD14B8D71B5662-if00,115200,rtscts' #nrf52dongle hci_uart usb cdc
 
 big_conf = { # TODO: use another dataclass for this to be able to iterate over the names
-    'broadcast_de': auracast_config.broadcast_de,
-    'broadcast_en': auracast_config.broadcast_en,
-    'broadcast_fr': auracast_config.broadcast_fr,
+    'broadcast_de': auracast_config.AuracastBigConfigDe(),
+    'broadcast_en': auracast_config.AuracastBigConfigEn(),
+    'broadcast_fr': auracast_config.AuracastBigConfigFr(),
     #auracast_config.broadcast_es,
     #auracast_config.broadcast_it,
 }