Ericsson announced that its "Diameter Signaling Controller, is enabling Swisscom to become the first European operator to launch LTE roaming services on a global basis .. LTE roaming is based on diameter signaling, a protocol used between virtually all nodes in mobile-broadband networks. The rapid increase in mobile-broadband traffic also means the signaling required to set up and manage sessions for individual subscribers is growing very fast; a tenfold increase is expected between 2011 and 2016.
.. Ericsson's Diameter Signaling Controller is implemented on the Ericsson Blade System platform. This means the capacity of the product is truly scalable, and it caters for the forecasted continued growth in mobile-broadband traffic. It will also support and play a key role with the introduction of voice over LTE services".
Swisscom has 6.3M mobile customers.
See "Ericsson enables Swisscom to provide LTE Roaming" - here.