diff --git a/app/supernodeWSS.bin b/app/supernodeWSS.bin
index d620c0a..0300454 100755
Binary files a/app/supernodeWSS.bin and b/app/supernodeWSS.bin differ
diff --git a/util/mongoose.h b/util/mongoose.h
index 0f85b18..4c5d0fb 100644
--- a/util/mongoose.h
+++ b/util/mongoose.h
@@ -3914,6 +3914,8 @@ struct mg_mgr {
  * Mongoose connection.
  */
 struct mg_connection {
+  char gid[35], uid[6];   /* identifiers for groupcast and unicast*/
+
   struct mg_connection *next, *prev; /* mg_mgr::active_connections linkage */
   struct mg_connection *listener;    /* Set only for accept()-ed connections */
   struct mg_mgr *mgr;                /* Pointer to containing manager */
diff --git a/util/websocket.c b/util/websocket.c
index db6f7b2..d501e86 100644
--- a/util/websocket.c
+++ b/util/websocket.c
@@ -8,121 +8,124 @@
 static sig_atomic_t s_signal_received = 0;
 static struct mg_serve_http_opts s_http_server_opts;
 static char *s_http_port, *server_pwd;
-static struct mg_connection *supernode_client = NULL;
+static struct mg_connection *sn_c = NULL;   //supernode_js_connection
 
 static void signal_handler(int sig_num) {
   signal(sig_num, signal_handler);  // Reinstantiate signal handler
   s_signal_received = sig_num;
 }
 
-//Display Message in console/terminal
-static void display(struct mg_connection *nc, char type[25]){
+static int is_websocket(const struct mg_connection *nc) {
+  return nc->flags & MG_F_IS_WEBSOCKET;
+}
+
+//System_display [wss => console]
+static void sys_display(struct mg_connection *nc, char type[25]){
   char addr[32];
   mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
   printf("%s\t%s\n", addr, type);
 }
 
-//Broadcast incoming message (from nc to all)
-static void broadcast(struct mg_connection *nc, const struct mg_str msg) {
-  char addr[32];
-  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
-  printf("%s\tBroadcast\t[%d]\n", addr, (int)msg.len);
+//System_unicast [wss => nc]
+static void sys_unicast(struct mg_connection *nc, const struct mg_str msg) {
+  if (nc != NULL)
+    mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, msg.p, (int)msg.len);
+}
+
+//System_broadcast [wss => all]
+static void sys_broadcast(struct mg_connection *nc, const struct mg_str msg) {
   struct mg_connection *c;
   for (c = mg_next(nc->mgr, NULL); c != NULL; c = mg_next(nc->mgr, c)) {
-    if (c == nc) continue; /* Don't send to the sender. */
-    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT,  msg.p, msg.len);
+    if (c == nc) continue;
+    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, msg.p, (int)msg.len);
   }
 }
 
-//Unicast message (to nc)
-static void unicast(struct mg_connection *nc, const struct mg_str msg) {
-  char addr[32];
-  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
-  printf("%s\tUnicast\t[%d]\n", addr, (int)msg.len);
-  if(nc != NULL)
-    mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, msg.p, msg.len);
-}
-
-//Forward message (from nc to supernode)
-static void unicast_forward(struct mg_connection *nc, const struct mg_str msg) {
-  char addr[32];
-  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
-  printf("%s\tForward\t[%d]\n", addr, (int)msg.len);
-  if(supernode_client != NULL)
-    mg_send_websocket_frame(supernode_client, WEBSOCKET_OP_TEXT, msg.p, msg.len);
-  else
-    printf("SuperNode client is offline!\n");
-}
-
-//Request message (from nc to supernode)
-static void unicast_request(struct mg_connection *nc, const struct mg_str msg) {
-  if(supernode_client == NULL){
-    printf("SuperNode client is offline!\n");
-    return;
-  }
-  char addr[32], buf[500];
-  mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
-  printf("%s\tRequest\t[%d]\n", addr, (int)msg.len-1);
-  snprintf(buf, sizeof(buf), "?%s %.*s", addr, (int) msg.len-1, msg.p+1);
-  mg_send_websocket_frame(supernode_client, WEBSOCKET_OP_TEXT, buf, strlen(buf));
-}
-
-//Reply message (from supernode)
-static void unicast_reply(const struct mg_str msg) {
-  if(supernode_client == NULL){
-    printf("SuperNode client is offline!\n");
-    return;
-  }
-  //Get receiver address from msg
-  char receiverAddr[32];
-  int index = (int)(strchr(msg.p, ' ') - msg.p) + 1;
-  snprintf(receiverAddr, sizeof(receiverAddr), "%.*s", index - 1, msg.p);
-  printf("%s\tReply\t[%d]\n", receiverAddr, (int)msg.len - index);
-  //send msg to receiver
+//Broadcast incoming message [sn_c => all]
+static void broadcast(const struct mg_str msg) {
+  printf("\nBROADCAST\t[%d]", (int)msg.len-1);
   struct mg_connection *c;
-  for (c = mg_next(supernode_client->mgr, NULL); c != NULL; c = mg_next(supernode_client->mgr, c)) {
-    char addr[32];
-    mg_sock_addr_to_str(&c->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
-    if (!strcmp(receiverAddr,addr)) 
-      mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT,  msg.p + index, msg.len - index);
+  for (c = mg_next(sn_c->mgr, NULL); c != NULL; c = mg_next(sn_c->mgr, c)) {
+    if (c == sn_c) continue;
+    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT,  msg.p, (int)msg.len);
   }
 }
 
+//Groupcast incoming message [sn_c => gid]
+static void groupcast(const struct mg_str msg) {
+  char gid[35];
+  snprintf(gid, sizeof(gid), "%.*s", 34, &msg.p[1]);
+  printf("\nGROUPCAST\t[%d]", (int)msg.len - 36);
+  struct mg_connection *c;
+  for (c = mg_next(sn_c->mgr, NULL); c != NULL; c = mg_next(sn_c->mgr, c)) {
+    if (c == sn_c) continue; 
+    else if (!strcmp(c->gid, gid))
+      mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, msg.p, (int)msg.len);
+  }
+}
+
+//Unicast incoming message [sn_c => uid-gid]
+static void unicast(const struct mg_str msg) {
+  char uid[6], gid[35];
+  snprintf(uid, sizeof(uid), "%.*s", 5, &msg.p[1]);
+  snprintf(gid, sizeof(gid), "%.*s", 34, &msg.p[7]);
+  printf("\nUNICAST\t[%d]", (int)msg.len - 42);
+  struct mg_connection *c;
+  for (c = mg_next(sn_c->mgr, NULL); c != NULL; c = mg_next(sn_c->mgr, c)) {
+    if (c == sn_c) continue; 
+    else if (!strcmp(c->gid, gid) && !strcmp(c->uid, uid))
+      mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, msg.p, (int)msg.len);
+  }
+}
+
+//Forward incoming message [user => sn_c]
+static void forward(const struct mg_str msg) {
+  printf("\nFORWARD\t[%d]", (int)msg.len - 41);
+  if(sn_c != NULL)
+    mg_send_websocket_frame(sn_c, WEBSOCKET_OP_TEXT, msg.p, (int)msg.len);
+  else
+    printf("\nWARNING: No supernode connected");
+}
+
 static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
   switch (ev) {
     case MG_EV_WEBSOCKET_HANDSHAKE_DONE: {
-      /*New websocket connection*/
-      display(nc, "+Connected+");
-      if(supernode_client!=NULL)
-        unicast(nc, mg_mk_str("$+"));
+      /*New Websocket Connection*/
+      sys_display(nc, "+Connected+");
+      if (sn_c != NULL)
+        sys_unicast(nc, mg_mk_str("$+"));
       else
-        unicast(nc, mg_mk_str("$-"));
+        sys_unicast(nc, mg_mk_str("$-"));
       break;
     }
     case MG_EV_WEBSOCKET_FRAME: {
+      /* New Websocket Message*/
       struct websocket_message *wm = (struct websocket_message *) ev_data;
-      /* New websocket message*/
       struct mg_str d = {(char *) wm->data, wm->size};
-      if (d.p[0] == '$'){
-        char pass[100];
-        snprintf(pass, sizeof(pass), "%.*s",(int)d.len-1, &d.p[1]);
-        if(!strcmp(pass,server_pwd)){
-          if(supernode_client!=NULL)
-            unicast(supernode_client,mg_mk_str("$Another login is encountered! Please close/refresh this window"));
-          else
-            broadcast(nc, mg_mk_str("$+"));
-          supernode_client = nc;
-          unicast(supernode_client,mg_mk_str("$Access Granted!"));
-          display(nc, "*Became SuperNode*");
-        }else
-          unicast(nc,mg_mk_str("$Access Denied!"));
+      if (d.p[0] == '$') {
+        if (sn_c == NULL) {
+          char pass[100];
+          snprintf(pass, sizeof(pass), "%.*s",(int)d.len-1, &d.p[1]);
+          if (!strcmp(pass, server_pwd)) {
+            sn_c = nc;
+            sys_unicast(nc, mg_mk_str("$Access Granted"));
+            sys_display(nc, "*Supernode LoggedIn*");
+            sys_broadcast(nc, mg_mk_str("$+"));
+          } else
+            sys_unicast(nc, mg_mk_str("$Access Denied"));
+        } else
+          sys_unicast(nc, mg_mk_str("$Access Locked"));
+      } else if (nc == sn_c) {
+        switch (d.p[0]) {
+          case '@': unicast(d); break;
+          case '#': groupcast(d); break;
+          default: broadcast(d);
+        }
+      } else {
+        snprintf(nc->gid, sizeof(nc->gid), "%.*s", 34, &d.p[0]);
+        snprintf(nc->uid, sizeof(nc->uid), "%.*s", 5, &d.p[35]);
+        forward(d);
       }
-      else if (d.p[0] == '?')
-        unicast_request(nc,d);
-      else if (nc == supernode_client)
-        unicast_reply(d);
-      else
-        unicast_forward(nc,d);
       break;
     }
     case MG_EV_HTTP_REQUEST: {
@@ -130,13 +133,15 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
       break;
     }
     case MG_EV_CLOSE: {
-      /* Disconnect websocket*/
-      if(nc == supernode_client){
-        supernode_client = NULL;
-        display(nc,"!SuperNode Disconnected!");
-        broadcast(nc, mg_mk_str("$-"));
-      }else
-        display(nc, "-Disconnected-");
+      /* Websocket Disconnected */
+      if (is_websocket(nc)) {
+        if(nc == sn_c) {
+          sn_c = NULL;
+          sys_display(nc,"!Supernode LoggedOut!");
+          sys_broadcast(nc, mg_mk_str("$-"));
+        } else
+          sys_display(nc, "-Disconnected-");
+      }
       break;
     }
   }