I created a bluetooth connection between nokia 6260 (Series 60) and GPS receiver over SPP. It trasfers to GPS some corrrection data from the Broadcaster using following:
bt_url = "btspp://" + bluetooth_address + ":1;

For testing I use bt dongle connected to PC. Data transfer works but it is sent within 512 bytes packets. For this kind of data it is too large. GPS receiver needs smaller packets to make better use of this correction data.
I tried to decrease this MTU size with something like this:
bt_url = "btspp://" + bluetooth_address + ":1;TransmitMTU=128;ReceiveMTU=128";
but without success.
I know that MTU params are used mainly in l2cap connection.

So questions are:
1. How can I decrease these packets within btssp?
2. What about using l2cap instead of spp? I don't know if GPS accepts this
3. What about use of time for sending packets? Is it possible to set e.x. transfer every 1 sec?

Thanks for help