diff --git a/simu/mec_database.py b/simu/mec_database.py
index 7a6cf232e2e97ed6c01d714f706bb8191e9314b3..9fb2cda0a7bc1f1e4aec53c1470717bd37aa08b9 100644
--- a/simu/mec_database.py
+++ b/simu/mec_database.py
@@ -153,6 +153,15 @@ class mec_database:
         return resp
     # End of method __to_transport_info__
 
+    def __to_rni_subscriptions__(self, p_subscription, p_subscription_type):
+        """ Build a RNI subscription Json message. """
+        print(">>> __to_rni_subscriptions__")
+        resp = "{\"CellChangeSubscription\": {\"subscriptionType\": \"" + p_subscription_type + "\",\"callbackReference\": \"http://meAppClient.example.com/rni/v2/notifications/cell_change/77777\", \"_links\": {\"self\": \"http://example.com/exampleAPI/rni/v2/subscriptions\"}, \"filterCriteria\": {\"appInsId\": \"01\", \"associateId\": [{\"type\": \"UE_IPV4_ADDRESS\", \"value\": 1}], \"plmn\": {\"mcc\": \"01\", \"mnc\": \"001\"}, \"cellId\": [\"0x800000A\"], \"hoStatus\": \"COMPLETED\"}, \"expiryDeadline\": {\"seconds\": 1577836800, \"nanoSeconds\": 0}}}"
+#        resp = "{\"CellChangeSubscription\": {\"callbackReference\": " + p_subscription['callbackReference'] + ", \"_links\": {\"self\": " + p_subscription['_links'] + "}, \"filterCriteria\": {\"appInsId\": " + p_subscription['filterCriteria']['appInsId'] + ", \"associateId\": [{\"type\": " + p_subscription['filterCriteria']['associateId']['type'] + ", \"value\": " + p_subscription['filterCriteria']['associateId']['value'] + "}], \"plmn\": {\"mcc\": " +  p_subscription['filterCriteria']['plmn']['mcc'] + ", \"mnc\": " + p_subscription['filterCriteria']['plmn']['mnc'] + "}, \"cellId\": [" + p_subscription['filterCriteria']['cellId'] + "], 'hoStatus': " + p_subscription['filterCriteria']['hoStatus'] + "}, \"expiryDeadline\": {\"seconds\": " + p_subscription['expiryDeadline']['seconds'] + ", \"nanoSeconds\": \"" + p_subscription['expiryDeadline']['nanoSeconds'] + "}}"
+        print("__to_rni_subscriptions__: ", resp)
+        return resp
+    # end of __to_rni_subscriptions__
+
     def getSubscriberList(self, p_uri):
         """ Build a SubscriberList Json message. """
         print(">>> getSubscriberList")
@@ -307,6 +316,14 @@ class mec_database:
         return resp
     # End of method getUEidentityTagInfo
 
+    def getBwAllocationAppInst(self, p_app_inst, p_ue_identity_tag):
+        print(">>> getBwAllocationAppInst: ", p_app_inst, ", ", p_ue_identity_tag)
+        resp = None
+        resp = "{\"bwInfo\": {\"timeStamp\": {\"seconds\": 0,\"nanoSeconds\": 0},\"appInsId\": \"string\",\"requestType\": \"APPLICATION_SPECIFIC_BW_ALLOCATION\",\"sessionFilter\": [{\"sourceIp\": \"string\",\"sourcePort\": [\"string\"],\"dstAddress\": \"string\",\"dstPort\": [\"string\"],\"protocol\": \"string\"}],\"fixedBWPriority\": \"not defined in the present document\",\"fixedAllocation\": \"string\",\"allocationDirection\": \"00 = Downlink (towards the UE)\"}}"
+        print("getBwAllocationAppInst: ", resp)
+        return resp
+    # End of method getBwAllocationAppInst
+
     def registerUEidentity(self, p_app_inst, p_json_msg):
         print(">>> registerUEidentity", p_json_msg)
         if p_json_msg["state"] != "REGISTERED" and p_json_msg["state"] != "UNREGISTERED":
@@ -363,12 +380,32 @@ class mec_database:
         return resp
     # End of unregisterSubscription
 
-    def getBwAllocationAppInst(self, p_app_inst, p_ue_identity_tag):
-        print(">>> getBwAllocationAppInst: ", p_app_inst, ", ", p_ue_identity_tag)
+    def registerRniSubscription(self, p_json_msg):
+        print(">>> registerRniSubscription: ", p_json_msg)
         resp = None
-        resp = "{\"bwInfo\": {\"timeStamp\": {\"seconds\": 0,\"nanoSeconds\": 0},\"appInsId\": \"string\",\"requestType\": \"APPLICATION_SPECIFIC_BW_ALLOCATION\",\"sessionFilter\": [{\"sourceIp\": \"string\",\"sourcePort\": [\"string\"],\"dstAddress\": \"string\",\"dstPort\": [\"string\"],\"protocol\": \"string\"}],\"fixedBWPriority\": \"not defined in the present document\",\"fixedAllocation\": \"string\",\"allocationDirection\": \"00 = Downlink (towards the UE)\"}}"
-        print("getBwAllocationAppInst: ", resp)
+        if p_json_msg['subscriptionType'] == 'CELL_CHANGE':
+            resp = self.__to_rni_subscriptions__(p_json_msg, 'CELL_CHANGE')
         return resp
-    # End of method getBwAllocationAppInst
+    # End of registerRniSubscription
+
+    def getRabInfo(self, p_cell_id):
+        print(">>> getRabInfo: ", p_cell_id)
+        resp = None
+        if p_cell_id == '0xFFFFFFFF':
+            resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+        else:
+            resp = "{ \"RabInfo\": { \"timeStamp\": { \"seconds\": 1577836800, \"nanoSeconds\": 0 }, \"appInsId\": \"01\", \"requestId\": \"01\", \"cellUserInfo\": { \"ecgi\": { \"plmn\": { \"mcc\": \"001\", \"mnc\": \"01\" }, \"cellId\": \"" + p_cell_id + "\" }, \"ueInfo\": { \"associateId\": null, \"type\": \"1\", \"value\": \"192.0.2.0\", \"erabInfo\": { \"erabId\": 10 }, \"erabQosParameters\": { \"qci\": 7, \"qosInformation\": { \"erabMbrDl\": 10, \"erabMbrUl\": 10, \"erabGbrDl\": 10, \"erabGbrUl\": 10 } } } } } }"
+        return resp
+    # End of getRabInfo
+
+    def getPlmnInfo(self, p_app_inst):
+        print(">>> getPlmnInfo: ", p_app_inst)
+        resp = None
+        if p_app_inst == '99':
+            resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+        else:
+            resp = "{ \"PlmnInfo\": { \"timeStamp\": { \"seconds\": 1577836800, \"nanoSeconds\": 0 }, \"appInsId\": \"" + p_app_inst + "\", \"ecgi\": { \"plmn\": { \"mcc\": \"001\", \"mnc\": \"01\" }, \"cellId\": \"0x800000A\" } } }"
+        return resp
+    # End of getPlmnInfo
 
 # End of class mec_database
diff --git a/simu/mec_http_server.py b/simu/mec_http_server.py
index 6cc35ef0b148b29421760c810b9bb39f0787f950..438871884bec4fbcc04a5c145725aa837ca36160 100644
--- a/simu/mec_http_server.py
+++ b/simu/mec_http_server.py
@@ -100,9 +100,8 @@ class myHandler(http.server.BaseHTTPRequestHandler):
             elif resp.find('Forbidden') != -1:
                 self.send_response(403, 'Forbidden')
                 resp = ""
-            elif resp.find('Bad Request') != -1:
+            elif resp.find('Bad Request') != -1 or resp.find('Wrong parameters') != -1:
                 self.send_response(400, 'Bad Request')
-                resp = ""
             elif resp.find('Precondition Failed') != -1:
                 self.send_response(412, 'Precondition Failed')
                 resp = "{\"problemDetails\": {\t\"type\": \"Precondition Failed\",\t\"title\": \"N/A\",\t\"status\": 412,\t\"detail\": \"Wrong preconditions\",\t\"instance\": \"N/A\"}}"
@@ -110,6 +109,8 @@ class myHandler(http.server.BaseHTTPRequestHandler):
             elif resp.find('userTrackingSubscription') != -1:
                 self.send_response(201, 'Created')
                 resp = ""
+            elif resp.find('CellChangeSubscription') != -1:
+                self.send_response(201, 'Created')
             else:
                 self.send_response(200, 'OK')
             self.send_header('Host', self.headers.get('Host')) # send_header() shall be after send_response()
@@ -172,9 +173,6 @@ class myHandler(http.server.BaseHTTPRequestHandler):
                 self.send_response(412, 'Precondition Failed')
                 resp = "{\"problemDetails\": {\t\"type\": \"Precondition Failed\",\t\"title\": \"N/A\",\t\"status\": 412,\t\"detail\": \"Wrong preconditions\",\t\"instance\": \"N/A\"}}"
                 content_type = 'application/problem+json'
-            elif resp.find('userTrackingSubscription') != -1:
-                self.send_response(201, 'Created')
-                resp = ""
             else:
                 self.send_response(200, 'OK')
             self.send_header('Host', self.headers.get('Host')) # send_header() shall be after send_response()
@@ -377,8 +375,7 @@ class myHandler(http.server.BaseHTTPRequestHandler):
                             content_type = 'application/problem+json'
         if (resp == None):
             resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"UEidentityAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
-            content_type = 'application/problem+json'
-        elif resp.find('problemDetails') != -1:
+        if resp.find('problemDetails') != -1:
             content_type = 'application/problem+json'
 
         print ("<<< __process__ue__identity__api__: ", resp, ", ", content_type)
@@ -393,24 +390,63 @@ class myHandler(http.server.BaseHTTPRequestHandler):
         if p_split[4].startswith('subscriptions'):
             if p_split.__len__() == 5:
                 s = p_split[4].split('?')
-                if s.__len__() == 1:
-                    resp = self.__db__.getSubscriptionLinkList(self.path)
+                if s.__len__() == 1: # Chek message body
+                    # Register/Unregister operation
+                    body = None
+                    # Extract the body if any
+                    content_len = int(self.headers.get('Content-Length'))
+                    if (content_len != 0):
+                        body = self.rfile.read(content_len)
+                        json_msg = self.__decode__json__body__(body)
+                        if (json_msg == None):
+                            resp = "{\"problemDetails\": {\t\"type\": \"Body processing not supported\",\t\"title\": \"UEidentityAPI\",\t\"status\": 400,\t\"detail\": \"Unknown request\",\t\"instance\": \"string\"}}"
+                        else:
+                            resp = self.__db__.registerRniSubscription(json_msg)
                 elif s[0] != 'subscriptions':
                     resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
-                    content_type = 'application/problem+json'
                 else:
                     s = s[1].split('=')
                     print('__process__rnis__api__: ', s)
                     if s[0] != 'subscription_type':
                         resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
-                        content_type = 'application/problem+json'
+                    elif s[1] == 'wrongSubscriptionType':
+                        resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
                     else:
                         resp = self.__db__.getSubscriptionLinkList(self.path)
             elif p_split.__len__() == 6:
                 if p_split[5] == '':
                     resp = self.__db__.getSubscriptionLinkList(self.path)
+                elif s[0] != 'subscriptions':
+                    resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+                else:
+                    s = s[1].split('=')
+                    print('__process__rnis__api__: ', s)
+                    if s[0] != 'subscription_type':
+                        resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+                    elif s[1] == 'wrongSubscriptionType':
+                        resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+                    else:
+                        resp = self.__db__.getSubscriptionLinkList(self.path)
+        elif p_split[4].startswith('queries'):
+            if p_split.__len__() == 5:
+                s = p_split[4].split('?')
+                if s.__len__() == 1: # Chek message body
+                    pass
+                else:
+                    if s[0] != 'queries':
+                        resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+                    else:
+                        s = s[1].split('=')
+                        print('__process__rnis__api__ (queries): ', s)
+                        if s[0] == 'cell_id':
+                            resp = self.__db__.getRabInfo(s[1])
+                        elif s[0] == 'plmn_info':
+                            resp = self.__db__.getPlmnInfo(s[1])
+                        else:
+                            resp = "{\"problemDetails\": {\t\"type\": \"Bad Request\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
         if (resp == None):
             resp = "{\"problemDetails\": {\t\"type\": \"Not supported\",\t\"title\": \"RnisAPI\",\t\"status\": 400,\t\"detail\": \"Wrong parameters\",\t\"instance\": \"string\"}}"
+        if resp.find('problemDetails') != -1:
             content_type = 'application/problem+json'
 
         print ("<<< __process__rnis__api__: ", resp, ", ", content_type)
@@ -481,6 +517,8 @@ class myHandler(http.server.BaseHTTPRequestHandler):
             return json_msg.get("ueIdentityTags")[0]
         elif ("userTrackingSubscription" in json_msg.keys()) == True:
             return json_msg.get("userTrackingSubscription")
+        elif ("CellChangeSubscription" in json_msg.keys()) == True:
+            return json_msg.get("CellChangeSubscription")
         return None
     # End of __decode__json__body__