diff --git a/examples/sandbox/ble/client-as-source/communication-ble-client-send/communication-ble-client-send.ino b/examples/sandbox/ble/client-as-source/communication-ble-client-send/communication-ble-client-send.ino
new file mode 100644
index 0000000000..be766c7062
--- /dev/null
+++ b/examples/sandbox/ble/client-as-source/communication-ble-client-send/communication-ble-client-send.ino
@@ -0,0 +1,39 @@
+/**
+ * @file communications-ble-client-send.ino
+ * @author Phil Schatzmann
+ * @brief Sending audio via BLE: the client acts as audio source
+ * @version 0.1
+ * @date 2022-11-04
+ *
+ * @copyright Copyright (c) 2022
+ */
+
+
+#include "AudioTools.h"
+#include "AudioCodecs/CodecADPCM.h" // https://github.com/pschatzmann/adpcm
+#include "Sandbox/BLE/AudioBLE.h"
+
+AudioInfo info(16000, 1, 16);
+SineWaveGenerator<int16_t> sineWave( 32000);  // subclass of SoundGenerator with max amplitude of 32000
+GeneratedSoundStream<int16_t> sound( sineWave);  // Stream generated from sine wave
+Throttle throttle(sound);
+AudioBLEClient ble;
+ADPCMEncoder adpcm(AV_CODEC_ID_ADPCM_IMA_WAV);
+EncodedAudioStream encoder(&ble, &adpcm);
+StreamCopy copier(encoder, throttle);
+
+void setup() {
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial, AudioLogger::Info);
+
+  sineWave.begin(info, N_B4);
+  throttle.begin(info);
+  encoder.begin(info);
+  ble.begin("ble-send", 60*10);
+
+  Serial.println("started...");
+}
+
+void loop() {
+  copier.copy();
+}
\ No newline at end of file
diff --git a/examples/sandbox/ble/client-as-source/communication-ble-server-receive/communication-ble-server-receive.ino b/examples/sandbox/ble/client-as-source/communication-ble-server-receive/communication-ble-server-receive.ino
new file mode 100644
index 0000000000..63ab3185d5
--- /dev/null
+++ b/examples/sandbox/ble/client-as-source/communication-ble-server-receive/communication-ble-server-receive.ino
@@ -0,0 +1,38 @@
+/**
+ * @file communications-ble-server-receive.ino
+ * @author Phil Schatzmann
+ * @brief Receiving audio via BLE: the server acts as audio sink
+ * @version 0.1
+ * @date 2022-11-04
+ *
+ * @copyright Copyright (c) 2022
+ */
+
+#include "AudioTools.h"
+#include "AudioCodecs/CodecADPCM.h" // https://github.com/pschatzmann/adpcm
+#include "Sandbox/BLE/AudioBLE.h"
+//#include "AudioLibs/AudioKit.h"
+
+AudioInfo info(16000, 1, 16);
+ADPCMDecoder adpcm(AV_CODEC_ID_ADPCM_IMA_WAV);
+I2SStream i2s; // or AudioKitStream ...
+EncodedAudioStream decoder(&i2s, &adpcm);
+AudioBLEServer ble;
+StreamCopy copier(decoder, ble);
+
+void setup() {
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial, AudioLogger::Warning);
+ 
+  decoder.begin(info);
+  
+  auto cfg = i2s.defaultConfig();
+  cfg.copyFrom(info);
+  i2s.begin(cfg);
+
+  ble.begin("ble-receive");
+}
+
+void loop() { 
+  copier.copy();
+}
\ No newline at end of file
diff --git a/examples/sandbox/ble/communication-ble-client/communication-ble-client.ino b/examples/sandbox/ble/server-as-source/communication-ble-client-receive/communication-ble-client-receive.ino
similarity index 81%
rename from examples/sandbox/ble/communication-ble-client/communication-ble-client.ino
rename to examples/sandbox/ble/server-as-source/communication-ble-client-receive/communication-ble-client-receive.ino
index 3f2269e5d8..f4ef9cff92 100644
--- a/examples/sandbox/ble/communication-ble-client/communication-ble-client.ino
+++ b/examples/sandbox/ble/server-as-source/communication-ble-client-receive/communication-ble-client-receive.ino
@@ -1,11 +1,11 @@
 /**
- * @file example-serial-receive.ino
+ * @file communications-ble-client-receive.ino
  * @author Phil Schatzmann
- * @brief Receiving audio via BLE and writing to I2S
+ * @brief Receiving audio via BLE: The client acts as audio sink and is writing to I2S
  * @version 0.1
- * @date 2022-03-09
+ * @date 2022-11-04
  *
- * @copyright Copyright (c) 2022
+ * @copyright Copyright (c) 2023
  */
 
 
diff --git a/examples/sandbox/ble/communication-ble-server/communication-ble-server.ino b/examples/sandbox/ble/server-as-source/communication-ble-server-send/communication-ble-server-send.ino
similarity index 83%
rename from examples/sandbox/ble/communication-ble-server/communication-ble-server.ino
rename to examples/sandbox/ble/server-as-source/communication-ble-server-send/communication-ble-server-send.ino
index 1f3a1545dd..233b917cac 100644
--- a/examples/sandbox/ble/communication-ble-server/communication-ble-server.ino
+++ b/examples/sandbox/ble/server-as-source/communication-ble-server-send/communication-ble-server-send.ino
@@ -1,11 +1,11 @@
 /**
- * @file communications-ble-send.ino
+ * @file communications-ble-server-send.ino
  * @author Phil Schatzmann
- * @brief Sending audio via BLE
+ * @brief Sending audio via BLE: The server acts as audio source
  * @version 0.1
- * @date 2022-03-09
+ * @date 2022-11-04
  *
- * @copyright Copyright (c) 2022
+ * @copyright Copyright (c) 2023
  */
 
 #include "AudioTools.h"
diff --git a/examples/tests/performance/throttle/throttle.ino b/examples/tests/performance/throttle/throttle.ino
new file mode 100644
index 0000000000..0eb64d5f55
--- /dev/null
+++ b/examples/tests/performance/throttle/throttle.ino
@@ -0,0 +1,20 @@
+#include "AudioTools.h"
+
+AudioInfo info(44100, 2, 16);
+SilenceGenerator<int16_t> silence;
+GeneratedSoundStream<int16_t> sound(silence);
+Throttle throttle(sound);
+MeasuringStream out(200, &Serial);
+StreamCopy copier(out, throttle);
+
+void setup() {
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial, AudioLogger::Warning);
+
+  out.begin(info);
+  sound.begin(info);
+  throttle.begin(info);
+
+}
+
+void loop() { copier.copy(); }
\ No newline at end of file
diff --git a/src/AudioCodecs/AudioEncoded.h b/src/AudioCodecs/AudioEncoded.h
index 5fd15f96fd..9f76dbe9a9 100644
--- a/src/AudioCodecs/AudioEncoded.h
+++ b/src/AudioCodecs/AudioEncoded.h
@@ -374,7 +374,7 @@ class EncodedAudioOutput : public AudioStream {
       return 0;
     }
 
-    if(availableForWrite()==0){
+    if(check_available_for_write && availableForWrite()==0){
       return 0;
     }
 
@@ -400,6 +400,10 @@ class EncodedAudioOutput : public AudioStream {
   void setLogLevel(AudioLogger::LogLevel level){
     custom_log_level.set(level);
   }
+  /// Is Available for Write check activated ?
+  bool isCheckAvailableForWrite() {
+      return check_available_for_write;
+  }
 
  protected:
   //AudioInfo info;
@@ -407,7 +411,8 @@ class EncodedAudioOutput : public AudioStream {
   AudioEncoder *encoder_ptr = CodecNOP::instance();  // decoder
   AudioWriter *writer_ptr = nullptr;
   Print *ptr_out = nullptr;
-  bool active;
+  bool active = false;
+  bool check_available_for_write = false;
   CustomLogLevel custom_log_level;
 };
 
diff --git a/src/AudioTools/AudioOutput.h b/src/AudioTools/AudioOutput.h
index 3e03927413..288d9dc7ed 100644
--- a/src/AudioTools/AudioOutput.h
+++ b/src/AudioTools/AudioOutput.h
@@ -731,92 +731,4 @@ class ChannelSplitOutput : public AudioOutput {
   Vector<ChannelSelectionOutputDef> out_chanels;
 };
 
-
-/**
- * @brief Configure Throttle setting
- * @author Phil Schatzmann
- * @copyright GPLv3
- */
-struct ThrottleConfig : public AudioInfo {
-  ThrottleConfig() {
-    sample_rate = 44100;
-    bits_per_sample = 16;
-    channels = 2;
-  }
-  int correction_us = 0;
-};
-
-
-/**
- * @brief Throttle the sending of the audio data to limit it to the indicated
- * sample rate.
- * @author Phil Schatzmann
- * @copyright GPLv3
- */
-class Throttle : public AudioOutput {
- public:
-  Throttle() = default;
-  Throttle(Print &out) { p_out = &out; } 
-
-  ThrottleConfig defaultConfig() {
-    ThrottleConfig c;
-    return c;
-  }
-
-  bool begin(ThrottleConfig info) {
-    AudioOutput::begin(info);
-    this->info = info;
-    return begin();
-  }
-
-  bool begin(){ 
-    info.copyFrom(cfg);
-    bytesPerSample = info.bits_per_sample / 8 * info.channels;
-    startDelay();
-    return true;
-  }
-
-  // (re)starts the timing
-  void startDelay() { 
-    start_time = micros(); 
-    sum_samples = 0;
-  }
-
-  int availableForWrite() {
-    if (p_out){
-      return p_out->availableForWrite();
-    }
-    return DEFAULT_BUFFER_SIZE;
-  }
-
-  size_t write(const uint8_t* data, size_t len){
-    size_t result = p_out->write(data, len);
-    delayBytes(len);
-    return result;
-  }
-
-  // delay
-  void delayBytes(size_t bytes) { delaySamples(bytes / bytesPerSample); }
-
-  // delay
-  void delaySamples(size_t samples) {
-    sum_samples += samples;
-    int64_t durationUsEff = micros() - start_time;
-    int64_t durationUsToBe = (sum_samples * 1000000) / info.sample_rate;
-    int64_t waitUs = durationUsToBe - durationUsEff + info.correction_us;
-    LOGI("wait: %d", (int)waitUs);
-    if (waitUs > 0) {
-      delayMicroseconds(waitUs);
-    }
-  }
-
- protected:
-  uint32_t start_time = 0;
-  uint32_t sum_samples = 0;
-  ThrottleConfig info;
-  int bytesPerSample = 0;
-  Print *p_out = nullptr;
-};
-
-
 } // namespace audio_tools
\ No newline at end of file
diff --git a/src/AudioTools/AudioPlayer.h b/src/AudioTools/AudioPlayer.h
index 45439aa090..f82adb837c 100644
--- a/src/AudioTools/AudioPlayer.h
+++ b/src/AudioTools/AudioPlayer.h
@@ -169,9 +169,7 @@ namespace audio_tools {
             autonext = p_source->isAutoNext();
 
             // initial audio info for fade from output when not defined yet
-            if (fade.audioInfo().channels==0){
-                setupFade();
-            }
+            setupFade();
             
             // start dependent objects
             p_out_decoding->begin();
diff --git a/src/AudioTools/AudioStreams.h b/src/AudioTools/AudioStreams.h
index 9f37650e61..a143399c4b 100644
--- a/src/AudioTools/AudioStreams.h
+++ b/src/AudioTools/AudioStreams.h
@@ -1062,8 +1062,18 @@ class MeasuringStream : public AudioStream {
       return start_time;
     }
 
-    void setBytesPerSample(int size){
-      sample_div = size;
+    void setAudioInfo(AudioInfo info){
+      AudioStream::info = info;
+      setFrameSize(info.bits_per_sample / 8 *info.channels);
+    }
+
+    bool begin(AudioInfo info){
+      setAudioInfo(info);
+      return true;
+    }
+
+    void setFrameSize(int size){
+      frame_size = size;
     }
 
   protected:
@@ -1074,7 +1084,7 @@ class MeasuringStream : public AudioStream {
     uint32_t start_time;
     int total_bytes = 0;
     int bytes_per_second = 0;
-    int sample_div = 0;
+    int frame_size = 0;
     NullStream null;
     Print *p_logout=nullptr;
 
@@ -1098,10 +1108,10 @@ class MeasuringStream : public AudioStream {
 
     void printResult() {
         char msg[70];
-        if (sample_div==0){
+        if (frame_size==0){
           sprintf(msg, "==> Bytes per second: %d", bytes_per_second);
         } else {
-          sprintf(msg, "==> Samples per second: %d", bytes_per_second/sample_div);
+          sprintf(msg, "==> Samples per second: %d", bytes_per_second/frame_size);
         }
         if (p_logout!=nullptr){
           p_logout->println(msg);
@@ -1270,6 +1280,130 @@ class ProgressStream : public AudioStream {
 
 };
 
+/**
+ * @brief Configure Throttle setting
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ */
+struct ThrottleConfig : public AudioInfo {
+  ThrottleConfig() {
+    sample_rate = 44100;
+    bits_per_sample = 16;
+    channels = 2;
+  }
+  int correction_us = 0;
+};
+
+/**
+ * @brief Throttle the sending or receiving of the audio data to limit it to the indicated
+ * sample rate.
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ */
+class Throttle : public AudioStream {
+ public:
+  Throttle() = default;
+  Throttle(Print &out) { p_out = &out; } 
+  Throttle(Stream &out) { p_out = &out; p_in = &out; } 
+
+  ThrottleConfig defaultConfig() {
+    ThrottleConfig c;
+    return c;
+  }
+
+  bool begin(ThrottleConfig cfg) {
+    LOGI("begin sample_rate: %d, channels: %d, bits: %d", info.sample_rate, info.channels, info.bits_per_sample);
+    this->info = cfg;
+    this->cfg = cfg;
+    return begin();
+  }
+
+  bool begin(AudioInfo info) {
+    LOGI("begin sample_rate: %d, channels: %d, bits: %d", info.sample_rate, info.channels, info.bits_per_sample);
+    this->info = info;
+    this->cfg.copyFrom(info);
+    return begin();
+  }
+
+  bool begin(){ 
+    frame_size = cfg.bits_per_sample / 8 * cfg.channels;
+    startDelay();
+    return true;
+  }
+
+  // (re)starts the timing
+  void startDelay() { 
+    start_time = micros(); 
+    sum_frames = 0;
+  }
+
+  int availableForWrite() {
+    if (p_out){
+      return p_out->availableForWrite();
+    }
+    return DEFAULT_BUFFER_SIZE;
+  }
+
+  size_t write(const uint8_t* data, size_t len){
+    size_t result = p_out->write(data, len);
+    delayBytes(len);
+    return result;
+  }
+
+  int available() {
+    if (p_in==nullptr) return 0;
+    return p_in->available();
+  }
+
+  size_t readBytes(uint8_t* data, size_t len){
+    if (p_in==nullptr) {
+      delayBytes(len);
+      return 0;
+    } 
+    size_t result = p_in->readBytes(data, len);
+    delayBytes(len);
+    return result;
+  }
+
+  // delay
+  void delayBytes(size_t bytes) { delayFrames(bytes / frame_size); }
+
+  // delay
+  void delayFrames(size_t frames) {
+    sum_frames += frames;
+    uint64_t durationUsEff = micros() - start_time;
+    uint64_t durationUsToBe = getDelayUs(sum_frames);
+    int64_t waitUs = durationUsToBe - durationUsEff + cfg.correction_us;
+    LOGI("wait us: %ld", waitUs);
+    if (waitUs > 0) {
+      int64_t waitMs = waitUs / 1000;
+      if (waitMs > 0) delay(waitMs);
+      delayMicroseconds(waitUs - (waitMs * 1000));
+    } else {
+      LOGD("negative delay!")
+    }
+  }
+
+  inline int64_t getDelayUs(uint64_t frames){
+    return (frames * 1000000) / cfg.sample_rate;
+  }
+
+  inline int64_t getDelayMs(uint64_t frames){
+    return getDelayUs(frames) / 1000;
+  }
+
+  inline int64_t getDelaySec(uint64_t frames){
+    return getDelayUs(frames) / 1000000l;
+  }
+
+ protected:
+  uint32_t start_time = 0;
+  uint32_t sum_frames = 0;
+  ThrottleConfig cfg;
+  int frame_size = 0;
+  Print *p_out = nullptr;
+  Stream *p_in = nullptr;
+};
 
 
 /**
diff --git a/src/AudioTools/Fade.h b/src/AudioTools/Fade.h
index 8512e6e7da..62e18d89a3 100644
--- a/src/AudioTools/Fade.h
+++ b/src/AudioTools/Fade.h
@@ -253,6 +253,7 @@ class FadeStream : public AudioStream {
   /// same as setStream
   void setOutput(Stream &io) {
     p_io = &io;
+    p_out = &io;
   }
 
   /// same as setOutput
@@ -277,6 +278,7 @@ class FadeStream : public AudioStream {
   int available() override { return p_io == nullptr ? 0 : p_io->available(); }
 
   size_t write(const uint8_t *buffer, size_t size) override {
+    if (p_out==nullptr) return 0;
     if (!active) {
       LOGE("%s", error_msg);
       return 0;
diff --git a/src/Sandbox/BLE/AudioBLEClient.h b/src/Sandbox/BLE/AudioBLEClient.h
index 009971c7d3..89224e56bf 100644
--- a/src/Sandbox/BLE/AudioBLEClient.h
+++ b/src/Sandbox/BLE/AudioBLEClient.h
@@ -70,17 +70,31 @@ class AudioBLEClient : public AudioBLEStream,
   size_t write(const uint8_t *data, size_t dataSize) override {
     TRACED();
     setupBLEClient();
-    int result = 0;
     if (!is_client_connected || !is_client_set_up)
       return 0;
-    if (ch02_char->canWrite()) {
-      ch02_char->writeValue((uint8_t *)data, dataSize, false);
-      result = dataSize;
+    if (!ch02_char->canWrite()){
+      return 0;
+    }
+
+    if (is_framed){
+      writeChannel2Characteristic(data, dataSize);
+      delay(1);
+    } else {
+      // send only data with max mtu
+      for (int j=0; j<dataSize; j++){
+        write_buffer.write(data[j]);
+        if (write_buffer.isFull()){
+          writeChannel2Characteristic(write_buffer.data(), write_buffer.available());
+          write_buffer.reset();
+        }
+      }
     }
-    return result;
+    return dataSize;
   }
 
-  int availableForWrite() override { return BLE_MTU - BLE_MTU_OVERHEAD; }
+  int availableForWrite() override { 
+    return is_framed ? (BLE_MTU - BLE_MTU_OVERHEAD) : DEFAULT_BUFFER_SIZE; 
+  }
 
   bool connected() override {
     if (!setupBLEClient()) {
@@ -89,7 +103,13 @@ class AudioBLEClient : public AudioBLEStream,
     return is_client_connected;
   }
 
-  void doLoop() { setupBLEClient(); }
+  void setWriteThrottle(int ms){
+    write_throttle = ms;
+  }
+
+  void setConfirmWrite(bool flag){
+    write_confirmation_flag = flag;
+  }
 
 protected:
   // client
@@ -105,6 +125,9 @@ class AudioBLEClient : public AudioBLEStream,
   BLEUUID BLUEID_CH1_UUID{BLE_CH1_UUID};
   BLEUUID BLUEID_CH2_UUID{BLE_CH2_UUID};
   BLEUUID BLUEID_INFO_UUID{BLE_INFO_UUID};
+  SingleBuffer<uint8_t> write_buffer{0};
+  int write_throttle = 0;
+  bool write_confirmation_flag = false;
 
   volatile bool is_client_connected = false;
   bool is_client_set_up = false;
@@ -125,6 +148,13 @@ class AudioBLEClient : public AudioBLEStream,
     info_char->writeValue((uint8_t *)&info, sizeof(AudioInfo));
   }
 
+  void writeChannel2Characteristic(const uint8_t*data, size_t len){
+    if (ch02_char->canWrite()) {
+      ch02_char->writeValue((uint8_t *)data, len, write_confirmation_flag);
+      delay(write_throttle);
+    }
+  }
+
   bool readAudioInfoCharacteristic(){
     if (!info_char->canRead())
       return false;
@@ -166,6 +196,11 @@ class AudioBLEClient : public AudioBLEStream,
 
     TRACEI();
 
+    // setup buffer
+    if (write_buffer.size()==0){
+      write_buffer.resize(getMTU() - BLE_MTU_OVERHEAD);
+    }
+
     if (p_client == nullptr)
       p_client = BLEDevice::createClient();