Mobile Networks: Tutorial

The 3GPP standard of 3µs phase difference between two air interfaces is what keeps the network synchronised, and all the services that rely on it working as expected.

Today we do practically everything with our smart phones. We use them for shopping, banking and is our main source of communication. We use it for sharing everything and as a source of entertainment, plus other things that we now take for granted. In order to have these services, we rely upon the telecommunications networks to keep us connected and functioning no matter where we are. Reliance on wireless communication has become such an integral part of our lives, that some may hesitate, to the point of struggling, if it were ever to be suddenly restricted.

Well that’s what would happen if the networks were to experience a drop in Sync accuracy – if the 3GPP limit was breached, going beyond the 3µs requirement. This translates through the ITU-T standards (G.8271.1/2 specifically) as 1.5µs at the network output from a single Basestation. Considering the consequences of poor Sync, it emphasises the need to test. However the only place to test this performance is on the air interface - the customer interface.

With a more connected world, comes the need for 5G networks, bringing with it even tighter sync requirements to provide more advanced connected services to ever growing populations. The importance of accurate Sync becomes even greater, and with it the increased need to test on the air interface – the customer interface.