diff --git a/src/signal_server.cpp b/src/signal_server.cpp
index 1091c61..dbde6ff 100644
--- a/src/signal_server.cpp
+++ b/src/signal_server.cpp
@@ -54,10 +54,31 @@ bool SignalServer::on_open(websocketpp::connection_hdl hdl) {
 }
 
 bool SignalServer::on_close(websocketpp::connection_hdl hdl) {
-  LOG_INFO("Websocket onnection [{}] closed", ws_connection_id_);
-  std::string user_id = transmission_manager_.GetUserId(hdl);
-  std::string transmission_id =
-      transmission_manager_.ReleaseGuestIdFromTransmission(hdl);
+  std::string user_id = transmission_manager_.ReleaseUserIdToWsHandle(hdl);
+  LOG_INFO("Websocket onnection [{}|{}] closed", ws_connections_[hdl], user_id);
+
+  bool is_host = false;
+  for (auto it = transmission_list_with_host_id_.begin();
+       it != transmission_list_with_host_id_.end(); it++) {
+    if (it->second == user_id) {
+      is_host = true;
+      break;
+    }
+  }
+
+  std::string transmission_id = "";
+
+  if (is_host) {
+    transmission_id =
+        transmission_manager_.ReleaseHostIdFromTransmission(user_id);
+
+    transmission_list_with_host_id_.erase(transmission_id);
+    transmission_manager_.ReleaseAllUserIdFromTransmission(transmission_id);
+    LOG_INFO("Release transmission [{}] due to host leaves", transmission_id);
+  } else {
+    transmission_id =
+        transmission_manager_.ReleaseGuestIdFromTransmission(user_id);
+  }
 
   if (!transmission_id.empty()) {
     json message = {{"type", "user_leave_transmission"},
@@ -67,22 +88,11 @@ bool SignalServer::on_close(websocketpp::connection_hdl hdl) {
     std::vector<std::string> user_id_list =
         transmission_manager_.GetAllUserIdOfTransmission(transmission_id);
 
-    if (user_id_list.empty()) {
-      transmission_list_.erase(transmission_id);
-      LOG_INFO("Release transmission [{}] due to no user in this transmission",
-               transmission_id);
-    }
-
-    if (transmission_manager_.IsHostOfTransmission(user_id, transmission_id)) {
-      transmission_list_.erase(transmission_id);
-      transmission_manager_.ReleaseAllUserIdFromTransmission(transmission_id);
-      LOG_INFO("Release transmission [{}] due to host leaves", transmission_id);
-    }
-
     for (const auto& user_id : user_id_list) {
       send_msg(transmission_manager_.GetWsHandle(user_id), message);
     }
   }
+
   ws_connections_.erase(hdl);
 
   return true;
@@ -129,12 +139,12 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
       std::string host_id = j["user_id"].get<std::string>();
       LOG_INFO("Receive host id [{}] create transmission request with id [{}]",
                host_id, transmission_id);
-      if (transmission_list_.find(transmission_id) ==
-          transmission_list_.end()) {
+      if (transmission_list_with_host_id_.find(transmission_id) ==
+          transmission_list_with_host_id_.end()) {
         if (transmission_id.empty()) {
           transmission_id = GenerateTransmissionId();
-          while (transmission_list_.find(transmission_id) !=
-                 transmission_list_.end()) {
+          while (transmission_list_with_host_id_.find(transmission_id) !=
+                 transmission_list_with_host_id_.end()) {
             transmission_id = GenerateTransmissionId();
           }
           LOG_INFO(
@@ -142,7 +152,7 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
               "[{}]",
               transmission_id);
         }
-        transmission_list_.insert(transmission_id);
+        transmission_list_with_host_id_[transmission_id] = host_id;
 
         transmission_manager_.BindHostIdToTransmission(host_id,
                                                        transmission_id);
@@ -183,11 +193,11 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
         send_msg(transmission_manager_.GetWsHandle(user_id), message);
       }
 
-      transmission_manager_.ReleaseGuestIdFromTransmission(hdl);
+      transmission_manager_.ReleaseGuestIdFromTransmission(user_id);
 
       if (transmission_manager_.IsHostOfTransmission(user_id,
                                                      transmission_id)) {
-        transmission_list_.erase(transmission_id);
+        transmission_list_with_host_id_.erase(transmission_id);
         transmission_manager_.ReleaseAllUserIdFromTransmission(transmission_id);
         LOG_INFO("Release transmission [{}] due to host leaves",
                  transmission_id);
diff --git a/src/signal_server.h b/src/signal_server.h
index b11f25c..7c37fe3 100644
--- a/src/signal_server.h
+++ b/src/signal_server.h
@@ -44,7 +44,7 @@ class SignalServer {
   std::map<room_id, connection_id> rooms_;
   unsigned int ws_connection_id_ = 0;
 
-  std::set<std::string> transmission_list_;
+  std::map<std::string, std::string> transmission_list_with_host_id_;
   TransmissionManager transmission_manager_;
 };
 
diff --git a/src/transmission_manager.cpp b/src/transmission_manager.cpp
index 5cf53fd..51007c9 100644
--- a/src/transmission_manager.cpp
+++ b/src/transmission_manager.cpp
@@ -97,6 +97,21 @@ bool TransmissionManager::BindUserIdToWsHandle(
   return true;
 }
 
+std::string TransmissionManager::ReleaseUserIdToWsHandle(
+    websocketpp::connection_hdl hdl) {
+  std::string user_id;
+  for (auto it = user_id_ws_hdl_list_.begin(); it != user_id_ws_hdl_list_.end();
+       ++it) {
+    if (it->second.lock().get() == hdl.lock().get()) {
+      user_id = it->first;
+      user_id_ws_hdl_list_.erase(it);
+      break;
+    }
+  }
+
+  return user_id;
+}
+
 bool TransmissionManager::IsHostOfTransmission(
     const std::string& user_id, const std::string& transmission_id) {
   if (transmission_host_id_list_.find(transmission_id) ==
@@ -106,26 +121,40 @@ bool TransmissionManager::IsHostOfTransmission(
   return transmission_host_id_list_[transmission_id] == user_id;
 }
 
-std::string TransmissionManager::ReleaseGuestIdFromTransmission(
-    websocketpp::connection_hdl hdl) {
-  for (auto it = user_id_ws_hdl_list_.begin(); it != user_id_ws_hdl_list_.end();
-       ++it) {
-    if (it->second.lock().get() == hdl.lock().get()) {
-      for (auto trans_it = transmission_guest_id_list_.begin();
-           trans_it != transmission_guest_id_list_.end(); ++trans_it) {
-        auto& guest_id_list = trans_it->second;
-        auto guest_id_it =
-            std::find(guest_id_list.begin(), guest_id_list.end(), it->first);
-        if (guest_id_it != guest_id_list.end()) {
-          guest_id_list.erase(guest_id_it);
-          LOG_INFO("Remove guest id [{}] from transmission [{}]", it->first,
-                   trans_it->first);
-          user_id_ws_hdl_list_.erase(it);
-          return trans_it->first;
-        }
-      }
+std::string TransmissionManager::ReleaseHostIdFromTransmission(
+    const std::string& host_id) {
+  std::string transmission_id;
+  for (auto trans_it = transmission_host_id_list_.begin();
+       trans_it != transmission_host_id_list_.end(); ++trans_it) {
+    if (trans_it->second == host_id) {
+      LOG_INFO("Remove host id [{}] from transmission [{}]", host_id,
+               trans_it->first);
+      transmission_id = trans_it->first;
+      transmission_host_id_list_.erase(trans_it);
+      return transmission_id;
     }
   }
+
+  return "";
+}
+
+std::string TransmissionManager::ReleaseGuestIdFromTransmission(
+    const std::string& guest_id) {
+  std::string transmission_id;
+  for (auto trans_it = transmission_guest_id_list_.begin();
+       trans_it != transmission_guest_id_list_.end(); ++trans_it) {
+    auto& guest_id_list = trans_it->second;
+    auto guest_id_it =
+        std::find(guest_id_list.begin(), guest_id_list.end(), guest_id);
+    if (guest_id_it != guest_id_list.end()) {
+      LOG_INFO("Remove guest id [{}] from transmission [{}]", guest_id,
+               trans_it->first);
+      transmission_id = trans_it->first;
+      guest_id_list.erase(guest_id_it);
+      return transmission_id;
+    }
+  }
+
   return "";
 }
 
diff --git a/src/transmission_manager.h b/src/transmission_manager.h
index d5e008a..38ab6e7 100644
--- a/src/transmission_manager.h
+++ b/src/transmission_manager.h
@@ -27,8 +27,10 @@ class TransmissionManager {
   bool IsHostOfTransmission(const std::string& user_id,
                             const std::string& transmission_id);
 
-  std::string ReleaseGuestIdFromTransmission(websocketpp::connection_hdl hdl);
+  std::string ReleaseHostIdFromTransmission(const std::string& host_id);
+  std::string ReleaseGuestIdFromTransmission(const std::string& guest_id);
 
+  std::string ReleaseUserIdToWsHandle(websocketpp::connection_hdl hdl);
   bool ReleaseAllUserIdFromTransmission(const std::string& transmission_id);
   bool ReleasePasswordFromTransmission(const std::string& transmission_id);