LTE BackhaulTechnology, Requirements and Trends in 2012 & 2013

Expectations are high for the needs of LTE backhaul: high capacity, high speed, and high quality of service. Providers are building out their new LTE networks at a fast pace, necessitating investments in LTE backhaul as those networks are turned on across the country.

LTE Backhaul: Technology
Despite being expensive and taking longer to deploy because of physical installation, fiber continues to be carriers’ preferred physical LTE backhaul technology as they make investments in urban and suburban coverage. According to Eric Bozich, vice president of marketing for CenturyLink’s wholesale division, wireless carriers consider fiber-based backhaul with Ethernet services to be required for an area to have full 3G/4G coverage.
However, as LTE backhaul requirements are expected to change with the move toward Heterogeneous Networks (HetNets) with large numbers of micro-, pico- and femtocells helping macro towers handle capacity needs.
Stuart Little, marketing director for microwave backhaul provider Aviat Networks, estimated that microwave links are on track to increase from five to 10 percent of backhaul, to 20 to 25 percent of cell site backhaul as carriers experiment with different types of backhaul for new network topologies.
Both Carrier Ethernet and MPLS (Multi-Protocol Label Switching) are technologies at work for carrying and routing mobile backhaul traffic in the most efficient way possible.
LTE Backhaul: Small Cells will change the game
“There are different architectures and technologies and solutions that the carriers are deploying for their 4G networking services, but the thing they all have in common is it allows them to squeeze more data out of the existing spectrum that they have,” said Erin Bozich, vice president of CenturyLink’s wholesale division. “In the most aggressive forecasts, the demand for wireless data is going to outpace what they can deliver, even with 4G technology, within the next few years.
“They’ve managed to stay ahead of the curve by moving from 3G to 4G and a variety of other strategies, things like WiFi offload strategies, to preserve the macro towers’ ability to handle it by themselves,” he added. “But we’re going to reach a point in the next couple of years where, even with 4G, they’re going to need to start subdividing those macro towers.
“That either means, build more macro towers, acquire more spectrum so you can use the existing towers … or start to deploy small cells. I think the reality is, it’s probably going to be a little bit of all three,” Bozich said. “We may see some more things done from a spectrum standpoint, but we think the small cell technology is really going to be the main tool that these wireless carriers will use to try to increase the capacity of the existing spectrum they have, and maintain the ability to provide the speeds and fees that customers with this insatiable appetite for wireless applications are going to require from them.”
He said that cost competitiveness and swift deployment will be key in deploying small cells.
“It’s a little bit of a strain, because these wireless carriers have real costs associated with deploying the small cell technology – but it doesn’t necessarily give them new customers. It’s a cost to keep up with the demands of the customers you have,” Bozich said.
LTE Backhaul: Dealing with Legacy Networks
However quickly wireless carriers move to LTE, though, the legacy 2G and 3G networks are not likely to be turned off anytime soon. Both of those legacy technologies provide reliable fall-back service and coverage in areas where 4G is not yet available, or in areas where there isn’t a good business case for priority LTE buildout.
Those networks will still need to be backhauled, which means that carriers must continue to maintain the less-efficient technologies, and/or explore LTE backhaul and network options that work with multiple technologies. Operators have looked to technologies such as Ethernet over TDM, where network equipment can convert frame relay traffic to Ethernet so that it can be carried over a packet-based network.
“They’re going to be living with the old technology for awhile,” said Glen Hunt, principal analyst for transport and routing infrastructure at Current Analysis.