Why is Diameter so important to LTE?

While the details are still somewhat shady, US-based mobile broadband company Tekelec has announced that a tier-one operator in the States has chosen it to provide a key component of its nationwide LTE network. This component is called Diameter: it’s vastly important, almost completely unheard of, and today we’re taking a quick look at it.

What’s the story?

You can’t be blamed if you’ve never heard of Diameter before – but it’s centrally important to the existence of LTE. In fact, it’s been incredibly important to the existence of IP networks and IMS as well. It’s a signalling protocol that allows all of the various systems within a mobile network to communicate with one another. Now, it used to be that the only time two systems needed to communicate was when you picked up your phone and made a call. But these days phones are constantly connected through the network – there is a never-ending stream of data between networks and smartphones. And it’s only going to get more complex as time goes by and more smartphones are activated. Diameter was chosen as the industry standard, because it’s the only protocol that can handle that degree of complexity, and scale up to deal with the unimaginable number of connections that are going to be active all the time in the future.

For more on Diameter, check out this excellent post: http://traffixsystems.blogspot.com/2011/06/diameter-for-technically-challenged.html

What’s the Tekelec deal?

We don’t know who the operator is, but we know what Tekelec will be doing with them. As this operator rolls out a nationwide LTE network across America, it will Tekelec’s job to deploy their Diameter Signaling Router (DSR). This will give the operator a signalling protocol that can manage hundreds of millions of subscribers at the same time – all of whom will be accessing data, roaming from network to network, and using advanced mobile features over their devices.

According to the release, ALL requests for apps and data will be routed through the DSR – which will be able to adjust network resources to support spikes in usage.

What we think?

The first time I wrote about Tekelec, I thought it was just an SMS company – but that was because during my interview with them, they happened to only talk about what they were currently doing with SMS.

Anyway, from the reading I’ve done on it, it seems that one of the big reasons for Diameter’s popularity is interoperability. Diameter adds a protocol layers that allows networks of many different types to communicate with one another. It allows 2G, 3G and 4G users to co-exist on the same network – and roam from one network to another without problem. Diameter exists at the very edges of the networks, and it seems that it will be the first point of contact between different mobile networks.