How to get a JSON object in PHP sent by Jquery

Question

I don't think that my question is so difficult to answer. I haved try t search all over but I don't get a sucess answer.

I have a JSON Object shaped with severals Array like this:

{1:{7:["Ready","Pro","WAK", "2"],16:["Pausa","Contra","KAW"]},8:["Cleab","Pro","WAK", "1"],16:["Build","Contra","KAW"]}

This is very good running because I can se the structure of the Json in the console

I want to send this Json to PHP and there read the Content and print or send to the DB, ect. I haved read something about serializearray() but this is only working with Forms elements. Most of the examples very good explained are in the oposite direccion, sending a Json to the CLient with the uses of the PHP function json_encode . This is not my case, I want the oposite from Jquery to PHP. I also read something about json_decode, but I don't know how to use it. Here is my js code:

var Obj1= {}
var Obj2= {};
var key;

    $("table tr.data").each(function(i) {
        var row = [];

        key = $(this).find('td').eq(0).find('input').val();

            row.push($(this).find('td').eq(1).text());
            row.push($(this).find('td').eq(2).text());
                        Obj2[key] = row;
        });
        Obj1[select.val()] = Obj2;

        var DataJSON = JSON.stringify(Obj1);
        alert(DataJSON);


        $.ajax({
            data: DataJSON,
            url:   'process.php,
            type:  'POST',
            dataType: 'json',
            beforeSend: function (){
                alert('Information wird gespeichert');
            },
            success:  function () {
              alert('Information wurde gespeichert');
            },
            error: function(){
                alert('Server antwortet nicht. Fehler..');
            }
        });

And this my php code only to read what I received from the client:

header('Content-Type: application/json');

    $data1 = json_decode($data);
    foreach ($data1 as $name => $value) {
        echo $name . ':';
        foreach ($value as $entry) {
            echo '  ' . $entry;
        }
    }

Can PLEASE somebody tell me what I'm doing wrong? How is the correct procedure? Thx!!