diff --git a/constants.go b/constants.go
index 3203973..7856fc6 100644
--- a/constants.go
+++ b/constants.go
@@ -46,6 +46,9 @@ const (
 	FileResponseTopicName string = "FileUploadResultTopic"
 	FileResponseTopic     string = "$oc/devices/{device_id}/sys/events/down"
 
-	FILE_ACTION_UPLOAD   string = "upload"
-	FILE_ACTION_DOWNLOAD string = "download"
+	FileActionUpload   string = "upload"
+	FileActionDownload string = "download"
+
+	// 设备或网关向平台发送请求
+	DeviceToPlatformTopic string = "$oc/devices/{device_id}/sys/events/up"
 )
diff --git a/handlers.go b/handlers.go
index 8bd4c79..5fc9da1 100644
--- a/handlers.go
+++ b/handlers.go
@@ -137,10 +137,10 @@ func CreateFileUploadDownLoadResultResponse(filename, action string, result bool
 		Paras: paras,
 	}
 	serviceEvent.ServiceId = "$file_manager"
-	if action == FILE_ACTION_DOWNLOAD {
+	if action == FileActionDownload {
 		serviceEvent.EventType = "download_result_report"
 	}
-	if action == FILE_ACTION_UPLOAD {
+	if action == FileActionUpload {
 		serviceEvent.EventType = "upload_result_report"
 	}
 	serviceEvent.EventTime = GetEventTimeStamp()
diff --git a/iot_http_client.go b/iot_http_client.go
index f264983..e836825 100644
--- a/iot_http_client.go
+++ b/iot_http_client.go
@@ -2,7 +2,6 @@ package iot
 
 import (
 	"bytes"
-	"fmt"
 	"github.com/golang/glog"
 	"io"
 	"io/ioutil"
@@ -24,7 +23,7 @@ type httpClient struct {
 }
 
 func (client *httpClient) DownloadFile(fileName, downloadUrl string) bool {
-	fmt.Println(downloadUrl)
+	glog.Infof("begin to download file %s, url = %s", fileName, downloadUrl)
 	fileName = SmartFileName(fileName)
 	out, err := os.Create(fileName)
 	if err != nil {
diff --git a/iotdevice.go b/iotdevice.go
index d0aedf6..cc1b26d 100644
--- a/iotdevice.go
+++ b/iotdevice.go
@@ -2,7 +2,6 @@ package iot
 
 import (
 	"encoding/json"
-	"fmt"
 	mqtt "github.com/eclipse/paho.mqtt.golang"
 	"github.com/golang/glog"
 	"github.com/satori/go.uuid"
@@ -10,7 +9,12 @@ import (
 	"time"
 )
 
+type Gateway interface {
+	UpdateSubDeviceState(subDevicesStatus SubDevicesStatus) bool
+}
+
 type Device interface {
+	Gateway
 	Init() bool
 	IsConnected() bool
 	SendMessage(message Message) bool
@@ -39,6 +43,31 @@ type iotDevice struct {
 	fileUrls                       map[string]string
 }
 
+func (device *iotDevice) UpdateSubDeviceState(subDevicesStatus SubDevicesStatus) bool {
+	glog.Infof("begin to update sub-devices status")
+
+	requestEventService := RequestEventService{
+		ServiceId: "$sub_device_manager",
+		EventType: "sub_device_update_status",
+		EventTime: GetEventTimeStamp(),
+		Paras:     subDevicesStatus,
+	}
+
+	request := Request{
+		ObjectDeviceId: device.Id,
+		Services:       []RequestEventService{requestEventService},
+	}
+
+	if token := device.client.Publish(FormatTopic(DeviceToPlatformTopic, device.Id), 1, false, Interface2JsonString(request));
+		token.Wait() && token.Error() != nil {
+		glog.Warningf("gateway %s update sub devices status failed", device.Id)
+		return false
+	}
+
+	glog.Info("gateway %s update sub devices status failed", device.Id)
+	return true
+}
+
 func (device *iotDevice) DownloadFile(filename string) bool {
 	// 构造获取文件上传URL的请求
 	requestParas := FileRequestServiceEventParas{
@@ -68,30 +97,28 @@ func (device *iotDevice) DownloadFile(filename string) bool {
 	for {
 		select {
 		case <-ticker:
-			_, ok := device.fileUrls[filename+FILE_ACTION_DOWNLOAD]
+			_, ok := device.fileUrls[filename+FileActionDownload]
 			if ok {
 				glog.Infof("platform send file upload url success")
 				goto ENDFOR
-			} else {
-				fmt.Println("get url failed")
 			}
 
 		}
 	}
 ENDFOR:
 
-	if len(device.fileUrls[filename+FILE_ACTION_DOWNLOAD]) == 0 {
+	if len(device.fileUrls[filename+FileActionDownload]) == 0 {
 		glog.Errorf("get file download url failed")
 		return false
 	}
 
-	downloadFlag := CreateHttpClient().DownloadFile(filename, device.fileUrls[filename+FILE_ACTION_DOWNLOAD])
+	downloadFlag := CreateHttpClient().DownloadFile(filename, device.fileUrls[filename+FileActionDownload])
 	if downloadFlag {
 		glog.Errorf("down load file { %s } failed", filename)
 		return false
 	}
 
-	response := CreateFileUploadDownLoadResultResponse(filename, FILE_ACTION_DOWNLOAD, downloadFlag)
+	response := CreateFileUploadDownLoadResultResponse(filename, FileActionDownload, downloadFlag)
 
 	token := device.client.Publish(device.topics[FileResponseTopicName], 1, false, Interface2JsonString(response))
 	if token.Wait() && token.Error() != nil {
@@ -125,40 +152,37 @@ func (device *iotDevice) UploadFile(filename string) bool {
 		token.Wait() && token.Error() != nil {
 		glog.Warningf("publish file upload request url failed")
 		return false
-	} else {
-		fmt.Println("send request success")
 	}
+	glog.Info("publish file upload request url success")
 
 	ticker := time.Tick(time.Second)
 	for {
 		select {
 		case <-ticker:
-			_, ok := device.fileUrls[filename+FILE_ACTION_UPLOAD]
+			_, ok := device.fileUrls[filename+FileActionUpload]
 			if ok {
 				glog.Infof("platform send file upload url success")
 				goto ENDFOR
-			} else {
-				fmt.Println("get url failed")
 			}
 
 		}
 	}
 ENDFOR:
 
-	if len(device.fileUrls[filename+FILE_ACTION_UPLOAD]) == 0 {
+	if len(device.fileUrls[filename+FileActionUpload]) == 0 {
 		glog.Errorf("get file upload url failed")
 		return false
 	}
-	glog.Infof("file upload url is %s", device.fileUrls[filename+FILE_ACTION_UPLOAD])
+	glog.Infof("file upload url is %s", device.fileUrls[filename+FileActionUpload])
 
 	//filename = SmartFileName(filename)
-	uploadFlag := CreateHttpClient().UploadFile(filename, device.fileUrls[filename+FILE_ACTION_UPLOAD])
+	uploadFlag := CreateHttpClient().UploadFile(filename, device.fileUrls[filename+FileActionUpload])
 	if !uploadFlag {
 		glog.Errorf("upload file failed")
 		return false
 	}
 
-	response := CreateFileUploadDownLoadResultResponse(filename, FILE_ACTION_UPLOAD, uploadFlag)
+	response := CreateFileUploadDownLoadResultResponse(filename, FileActionUpload, uploadFlag)
 
 	token := device.client.Publish(device.topics[FileResponseTopicName], 1, false, Interface2JsonString(response))
 	if token.Wait() && token.Error() != nil {
@@ -248,10 +272,10 @@ func (device *iotDevice) createFileUrlResponseMqttHandler() func(client mqtt.Cli
 
 		fileName := response.Services[0].Paras.ObjectName
 		eventType := response.Services[0].EventType
-		if strings.Contains(eventType, FILE_ACTION_UPLOAD) {
-			device.fileUrls[fileName+FILE_ACTION_UPLOAD] = response.Services[0].Paras.Url
+		if strings.Contains(eventType, FileActionUpload) {
+			device.fileUrls[fileName+FileActionUpload] = response.Services[0].Paras.Url
 		} else {
-			device.fileUrls[fileName+FILE_ACTION_DOWNLOAD] = response.Services[0].Paras.Url
+			device.fileUrls[fileName+FileActionDownload] = response.Services[0].Paras.Url
 		}
 
 	}
@@ -295,8 +319,6 @@ func (device *iotDevice) Init() bool {
 	options.SetClientID(assembleClientId(device))
 	options.SetUsername(device.Id)
 	options.SetPassword(HmacSha256(device.Password, TimeStamp()))
-	fmt.Println(assembleClientId(device))
-	fmt.Println(HmacSha256(device.Password, TimeStamp()))
 
 	device.client = mqtt.NewClient(options)
 
diff --git a/request.go b/request.go
new file mode 100644
index 0000000..3a0d832
--- /dev/null
+++ b/request.go
@@ -0,0 +1,24 @@
+package iot
+
+//设备或网关请求的通用消息体
+type Request struct {
+	ObjectDeviceId string                `json:"object_device_id"`
+	Services       []RequestEventService `json:"services"`
+}
+type RequestEventService struct {
+	ServiceId string      `json:"service_id"`
+	EventType string      `json:"event_type"`
+	EventTime string      `json:"event_time"`
+	Paras     interface{} `json:"paras"` // 不同类型的请求paras使用的结构体不同
+}
+
+// 1 网关更新子设备状态
+
+type SubDevicesStatus struct {
+	DeviceStatuses []DeviceStatus `json:"device_statuses"`
+}
+
+type DeviceStatus struct {
+	DeviceId string `json:"device_id"`
+	Status   string `json:"status"` // 子设备状态。 OFFLINE：设备离线 ONLINE：设备上线
+}
diff --git a/samples/gateway/gateway_demo.go b/samples/gateway/gateway_demo.go
new file mode 100644
index 0000000..9b648b6
--- /dev/null
+++ b/samples/gateway/gateway_demo.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	iot "github.com/ctlove0523/huaweicloud-iot-device-sdk-go"
+)
+
+func main() {
+	device := iot.CreateIotDevice("5fdb75cccbfe2f02ce81d4bf_go-mqtt", "123456789", "tcp://iot-mqtts.cn-north-4.myhuaweicloud.com:1883")
+	device.Init()
+
+	subDevice1 := iot.DeviceStatus{
+		DeviceId: "5fdb75cccbfe2f02ce81d4bf_sub-device-1",
+		Status:   "ONLINE",
+	}
+	subDevice2 := iot.DeviceStatus{
+		DeviceId: "5fdb75cccbfe2f02ce81d4bf_sub-device-2",
+		Status:   "ONLINE",
+	}
+
+	subDevice3 := iot.DeviceStatus{
+		DeviceId: "5fdb75cccbfe2f02ce81d4bf_sub-device-3",
+		Status:   "ONLINE",
+	}
+
+	devicesStatus := []iot.DeviceStatus{subDevice1, subDevice2, subDevice3}
+
+	ok := device.UpdateSubDeviceState(iot.SubDevicesStatus{
+		DeviceStatuses: devicesStatus,
+	})
+	if ok {
+		fmt.Println("gateway update sub devices status success")
+	} else {
+		fmt.Println("gateway update sub devices status failed")
+	}
+}