Why your 5G network needs 5G transport
Transport has always been the “middle child” of the network— an essential part of the family that’s often underappreciated and ignored. But as the next wave of mobile communications, with LTE Advanced and 5G, sweeps us forward, it’s time to take notice of the supporting RAN Transport.
To understand what to expect in the transition from 4G to 5G, let’s take a look back at what happened in the previous mobile network “G transitions.”
Want a quick guide to the key network design requirements behind 5G? Download our 5G Radio Access Network Architecture – Design Guidelines and Key Considerations paper.
The transport network buying cycle
This might date me, but do you remember the 2G days, way back in 1991 when the first GSM network went online? Voice was king, and the backhaul connectivity was on the order of 100Kbps, using such technologies as fractional DS1/E1 circuits over copper cables and PDH connections over microwave.
Then Ericsson introduced 3G. The availability of mobile data changed the game overnight . Service Providers jumped to deploy the 3G radios — only to learn that backhaul capacity demand increased by an order of magnitude. Suddenly, they realized that they needed 1Mbps transport. A complete transport buying cycle was sparked as operators refreshed the backhaul to 1Mbps using technologies like T1/E1 over copper and ATM-based OC-3/STM-1 over fiber optic connections.
The cycle repeated itself in the 4G evolution. Operators bought and deployed 4G/LTE radios, only to learn that the backhaul capacity demand increased by an order of magnitude … AGAIN!
The new benchmark for backhaul connectivity went to 1Gbps. And again, another transport buying cycle was created, as SPs upgraded their backhaul to Gigabit Ethernet.
And this is where we stand today.
What transport bandwidth can we expect for 5G?
The coming 5G wave will create yet another transport network buying cycle. As mobile carriers roll out their first Massive MIMO radios and 5G new radios, they will find that 1Gbps coming off the cell site will not be enough.
Transport dimensioning calculations show that implementing LTE-advanced technologies like carrier aggregation, CoMP, and LAA, along with 5G New Radio and new RAN architectures like Centralized RAN, will drive the transport bandwidth requirements significantly higher that 1Gbps. The new benchmark for transport in the 5G era is 10Gbps Ethernet, running over fiber optics or microwave radio links.
Ericsson’s early empirical data backs up the math.
During a recent Massive MIMO deployment with a Tier-1 U.S. service provider, the operator connected their new Massive MIMO radios to their already installed legacy cell site routers. After being on air for some time 62% of sites needed an upgrade to their current cell site routers from 1Gbps to 10Gbps.
In this case, the increase in traffic from rolling out Massive MIMO radios created a transport upgrade need for a majority of those sites.
A transport network for future generation requirements
As today’s operators consider their move to LTE-Advanced and 5G, it’s time they avoided the added costs and risks of retrofitting and began preparing Transport networks for future generations from day one.
Today’s major service providers are already announcing 5G rollouts and tests, which means they’re speeding ahead in developing RAN evolution plans. Now’s the perfect opportunity for providers to break inefficient old habits and plan ahead to make sure they’re out in front of the RAN transport buying cycle.