diff --git a/prover_rclcpp/CMakeLists.txt b/prover_rclcpp/CMakeLists.txt
index 889c129..29bbb39 100644
--- a/prover_rclcpp/CMakeLists.txt
+++ b/prover_rclcpp/CMakeLists.txt
@@ -65,6 +65,9 @@ custom_executable(rclcpp_1566)
 #custom_executable(rclcpp_1580)
 custom_executable(rclcpp_1585)
 #custom_executable(rclcpp_1597)
+custom_executable(rclcpp_1611_client)
+custom_executable(rclcpp_1611_publisher)
+custom_executable(rclcpp_1611_server)
 
 #custom_executable(ros2_644)
 #custom_executable(ros2_946_pub)
diff --git a/prover_rclcpp/src/rclcpp_1611_client.cpp b/prover_rclcpp/src/rclcpp_1611_client.cpp
new file mode 100644
index 0000000..1aa566f
--- /dev/null
+++ b/prover_rclcpp/src/rclcpp_1611_client.cpp
@@ -0,0 +1,94 @@
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <rclcpp/rclcpp.hpp>
+#include <std_msgs/msg/bool.hpp>
+#include <std_srvs/srv/trigger.hpp>
+
+class CallbackGroupSrvClient: public rclcpp::Node {
+public:
+  // Constructor
+  CallbackGroupSrvClient()
+  : Node("callback_group_srv_client"){
+
+    // Init callback group
+    callback_group_ = this->create_callback_group(rclcpp::CallbackGroupType::MutuallyExclusive, false);
+    callback_group_executor_thread_ = std::thread([this]() {
+      callback_group_executor_.add_callback_group(callback_group_, this->get_node_base_interface());
+      callback_group_executor_.spin();
+    });
+
+    // Init subscription
+    subscription_ = this->create_subscription<std_msgs::msg::Bool>(
+          "topic_bool",
+          rclcpp::QoS(1),
+          std::bind(
+            &CallbackGroupSrvClient::sub_callback,
+            this,
+            std::placeholders::_1
+            )
+          );
+
+    // Create service client and link it to callback group
+    srv_client_ = this->create_client<std_srvs::srv::Trigger>(
+          "trigger_srv",
+          rmw_qos_profile_services_default,
+          callback_group_
+          );
+  }
+
+  // Destructor
+  ~CallbackGroupSrvClient(){
+    callback_group_executor_.cancel();
+    callback_group_executor_thread_.join();
+  }
+
+private:
+  // Methods
+  void sub_callback(const std_msgs::msg::Bool::SharedPtr ){
+    RCLCPP_INFO_STREAM(this->get_logger(), "Received new msg! ");
+
+    // Send request and wait for future
+    auto req = std::make_shared<std_srvs::srv::Trigger::Request>();
+    auto future = srv_client_->async_send_request(req);
+    RCLCPP_INFO_STREAM(this->get_logger(), "Sending request");
+    auto future_status = future.wait_for(std::chrono::seconds(10));
+
+    // Process result
+    if (future_status == std::future_status::ready) {
+      if (future.get()->success) {
+        RCLCPP_INFO_STREAM(this->get_logger(), "Srv suceeded");
+      }
+      else {
+        RCLCPP_INFO_STREAM(this->get_logger(), "Srv failed");
+      }
+    }
+    else if (future_status == std::future_status::timeout) {
+      RCLCPP_INFO_STREAM(this->get_logger(), "Response not received within timeout");
+    }
+    else if (future_status == std::future_status::deferred) {
+      RCLCPP_INFO_STREAM(this->get_logger(), "Srv deferred");
+    }
+
+    return;
+  }
+
+  // Attributes
+  rclcpp::Subscription<std_msgs::msg::Bool>::SharedPtr subscription_;
+  rclcpp::CallbackGroup::SharedPtr callback_group_;
+  rclcpp::executors::SingleThreadedExecutor callback_group_executor_;
+  std::thread callback_group_executor_thread_;
+  rclcpp::Client<std_srvs::srv::Trigger>::SharedPtr srv_client_;
+};
+
+
+
+int main(int argc, char * argv[]){
+  rclcpp::init(argc, argv);
+  auto client = std::make_shared<CallbackGroupSrvClient>();
+  rclcpp::spin(client);
+  rclcpp::shutdown();
+  return 0;
+}
\ No newline at end of file
diff --git a/prover_rclcpp/src/rclcpp_1611_publisher.cpp b/prover_rclcpp/src/rclcpp_1611_publisher.cpp
new file mode 100644
index 0000000..e046db9
--- /dev/null
+++ b/prover_rclcpp/src/rclcpp_1611_publisher.cpp
@@ -0,0 +1,46 @@
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <rclcpp/rclcpp.hpp>
+#include <std_msgs/msg/bool.hpp>
+
+
+class MinimalPublisher: public rclcpp::Node {
+public:
+  // constructor
+  MinimalPublisher()
+  : Node("minimal_publisher"){
+    publisher_ = this->create_publisher<std_msgs::msg::Bool>("topic_bool", rclcpp::QoS(1));
+    timer_ = this->create_wall_timer(
+          std::chrono::seconds(5),
+          std::bind(
+            &MinimalPublisher::timer_callback,
+            this
+            )
+          );
+  }
+
+private:
+  // method
+  void timer_callback(){
+    std_msgs::msg::Bool msg;
+    msg.data = false;
+    publisher_->publish(msg);
+    RCLCPP_INFO_STREAM(this->get_logger(), "Publishing data! ");
+    return;
+  }
+
+  // attributes
+  rclcpp::TimerBase::SharedPtr timer_;
+  rclcpp::Publisher<std_msgs::msg::Bool>::SharedPtr publisher_;
+};
+
+int main(int argc, char * argv[]){
+  rclcpp::init(argc, argv);
+  auto pub = std::make_shared<MinimalPublisher>();
+  rclcpp::spin(pub);
+  rclcpp::shutdown();
+  return 0;
+}
\ No newline at end of file
diff --git a/prover_rclcpp/src/rclcpp_1611_server.cpp b/prover_rclcpp/src/rclcpp_1611_server.cpp
new file mode 100644
index 0000000..51a4864
--- /dev/null
+++ b/prover_rclcpp/src/rclcpp_1611_server.cpp
@@ -0,0 +1,92 @@
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <rclcpp/rclcpp.hpp>
+#include <std_msgs/msg/bool.hpp>
+#include <std_srvs/srv/trigger.hpp>
+
+
+class CallbackGroupSrvServer: public rclcpp::Node {
+public:
+  // Constructor
+  CallbackGroupSrvServer()
+  : Node("callback_group_srv_server"){
+    // Init callback group and spin it
+    callback_group_ = this->create_callback_group(rclcpp::CallbackGroupType::MutuallyExclusive, false);
+    //callback_group_ = this->create_callback_group(rclcpp::CallbackGroupType::Reentrant, false);
+    callback_group_executor_thread_ = std::thread([this]() {
+      callback_group_executor_.add_callback_group(callback_group_, this->get_node_base_interface());
+      callback_group_executor_.spin();
+    });
+
+    // Init service server and link it to callback group
+    service_ = this->create_service<std_srvs::srv::Trigger>(
+          "trigger_srv",
+          std::bind(
+            &CallbackGroupSrvServer::srv_callback,
+            this,
+            std::placeholders::_1,
+            std::placeholders::_2)
+          );
+  }
+
+  // Destructor
+  ~CallbackGroupSrvServer(){
+    callback_group_executor_.cancel();
+    callback_group_executor_thread_.join();
+  }
+
+private:
+  // Methods
+  void sub_callback(const std_msgs::msg::Bool::SharedPtr ){
+    new_msg_ = true;
+    RCLCPP_INFO_STREAM(this->get_logger(), "Received new msg!");
+    return;
+  }
+
+  void srv_callback(const std_srvs::srv::Trigger::Request::SharedPtr, std_srvs::srv::Trigger::Response::SharedPtr res){
+    RCLCPP_INFO_STREAM(this->get_logger(), "Received request");
+    new_msg_ = false;
+
+    // Create subscription
+    auto sub_options_ = rclcpp::SubscriptionOptions();
+    sub_options_.callback_group = callback_group_;
+    auto subscription = this->create_subscription<std_msgs::msg::Bool>(
+          "topic_bool",
+          rclcpp::QoS(1),
+          std::bind(
+            &CallbackGroupSrvServer::sub_callback,
+            this,
+            std::placeholders::_1),
+          sub_options_
+          );
+
+    // Wait for new_msg
+    while (rclcpp::ok()
+           && new_msg_ == false) {
+      rclcpp::sleep_for(std::chrono::seconds(1));
+      RCLCPP_INFO_STREAM(this->get_logger(), "Sleep...");
+    }
+
+    res->message = "";
+    res->success = true;
+    return;
+  }
+
+  // Attributes
+  rclcpp::Service<std_srvs::srv::Trigger>::SharedPtr service_;
+  rclcpp::CallbackGroup::SharedPtr callback_group_;
+  rclcpp::executors::SingleThreadedExecutor callback_group_executor_;
+  std::thread callback_group_executor_thread_;
+  bool new_msg_;
+};
+
+int main(int argc, char * argv[]){
+  rclcpp::init(argc, argv);
+  auto srv_server = std::make_shared<CallbackGroupSrvServer>();
+  rclcpp::spin(srv_server);
+  rclcpp::shutdown();
+  return 0;
+}
\ No newline at end of file