diff --git a/doc/ConnectionGroups.md b/doc/ConnectionGroups.md
new file mode 100644
index 0000000..f9010d5
--- /dev/null
+++ b/doc/ConnectionGroups.md
@@ -0,0 +1,16 @@
+# ConnectionGroups
+
+Often websocket connections share a context. This could be a room for a chat, an URI for pushing updates, or anything else where one client need to be able to send messages directly or indirectly to other clients. This is the problem that *ConnectionGroups* solve.
+
+A `WebSocketConnection` can, but doesn't have to, be part of a group. The group is set using `WebSocketConnection::setGroup(string $name)` with groups being created and destroyed on the fly. Once part of a group, the other members of the group can be addressed:
+
+```php
+$websocket->setGroup("somename");
+
+// Note: use getGroupName() to get the group name
+foreach ($websocket->getGroup() as $other) {
+  $other->write("Hello");
+}
+```
+
+To remove a group from a connection, call `setGroup(null)`.
diff --git a/src/WebSocketConnection.php b/src/WebSocketConnection.php
index 075b5c7..e5586dd 100644
--- a/src/WebSocketConnection.php
+++ b/src/WebSocketConnection.php
@@ -214,25 +214,28 @@ class WebSocketConnection implements WebSocketInterface
     }
 
     public function write($data)
-    {
-        // Header; final, text frame, unmasked
-        $frame = chr(0x81) . chr(strlen($data)) . $data;
-
-        $this->outStream->write($frame);
+    {           
+        return $this->send(self::OP_FRAME_TEXT, $data);
     }
 
-    public function send(int $opcode, bool $final, string $data)
+    /**
+     * 
+     */
+    public function send(int $opcode, string $data, bool $final = true)
     {
         $frame = chr(($final?0x80:0x00) | ($opcode & 0xF));
         
         $len = strlen($data);
         if ($len > 126) {
             $frame .= chr(0x7E) . chr(($len >> 8) & 0xFF) . chr($len & 0xFF);
+        } else {
+            $frame .= chr($len);
         }
         $frame .= $data;
 
         $this->outStream->write($frame);
 
+        return true;
     }
 
     public function close()
@@ -245,5 +248,25 @@ class WebSocketConnection implements WebSocketInterface
     {
         
     }
-    
+
+    // private function hexdump($data): void
+    // {
+    //     printf("%4d .\n", strlen($data));
+    //     $rows = str_split($data, 16);
+    //     $offs = 0;
+    //     foreach ($rows as $row) {
+    //         $h = []; $a = [];
+    //         for ($n = 0; $n < 16; $n++) {
+    //             if ($n < strlen($row)) {
+    //                 $h[] = sprintf("%02x%s", ord($row[$n]), ($n==7)?"  ":" ");
+    //                 $a[] = sprintf("%s%s", (ctype_print($row[$n])?$row[$n]:"."), ($n==7)?" ":"");
+    //             } else {
+    //                 $h[] = (($n==7)?"    ":"   ");
+    //                 $a[] = (($n==7)?"  ":" ");
+    //             }
+    //         }
+    //         printf("%04x | %s | %s\n", 16 * $offs++, join("", $h), join("", $a));
+    //     }
+    // }
+
 }
\ No newline at end of file