Backhaul for Mobile Networks Has a Place for Wireless Links

July 12, 2016

Part Four — Wireless backhaul holds promise for U.S. deployment to serve macrocell sites, small cells and the growing data traffic from small cells that will have to be aggregated at macrocell sites.

By Don Bishop

Executive Editor
Associate Publisher
AGL Magazine

July 12, 2016 — Capacity, speed of deployment and optimization are the key factors involved with wireless backhaul, according to Shai Yaniv, vice president of marketing at Ceragon Networks, a company that provides high-capacity microwave Ethernet and time-division multiplexing wireless backhaul to wireless service providers and private businesses.

Shai Yaniv, VP, marketing, Ceragon Networks, at the Tower & Small Cell Summit. Photo by Don Bishop

New spectrum and spectral efficiency affect capacity, and Yaniv said new technologies, including new radio technologies, enable spectral efficiency to rise. New spectrum provides wider radio channels, which he likened to real estate. “Real estate is important on the towers; otherwise, we’re just going to load them with tons of equipment and they’re going to fail,” he said. Yaniv spoke at the Tower & Small Cell Summit session “Macro Tower Backhaul Solutions” led by Jennifer P. Clark, vice president of research at 451 Research, a New York-based market research and consulting company. An electrical engineer, Yaniv has 20 years of experience in marketing, product management and business development.

Satisfying the expectations of those who purchase backhaul equipment and those who use backhaul service calls for speedy deployment, which in turn means equipment configurations that make it as easy as possible for field technicians to make installations quickly and cost-efficiently.

Network optimization involves self-defining networks and using network analytics to ensure awareness of capacity, congestion, shortages, and where optimization is necessary.

In Yaniv’s view, the use of long-lasting, adaptable backhaul is important because cellular networks evolve, and many technology developments are coming to market. Ecosystems need to be formed around small cells, self-defining networks and fifth-generation (5G) cellular. It makes backhaul complex because it’s uncertain which of the emerging technologies will dominate. This means mobile network operators need to have wireless and wireline infrastructure in place that they can count on, thus avoiding the need to replace it with the release of new services, which would impair network operational efficiency.

To take the infrastructure where it needs to be, Ceragon focuses on backhaul for 4G to 4.5G and 5G cellular networks. Its products serve radio access network (RAN) and long-range backhaul required in many U.S. locations and elsewhere for aggregation network backhaul. The company also is focusing on small cell backhaul. Its products are in use by 400 network operators in more than 130 countries.

Five years ago, backhaul capacity for cell sites was about 50 Mbps, Yaniv said. Today’s capacity requirements are approaching 1 Gbps. “The 1 Gbps capacity requirement does not need to be operational to serve today’s data traffic volume,” Yaniv said. “But when operators are looking to modernize the network, we look at the equipment at the cell site moving into 4G and improving the infrastructure on-site going full packet. That calls for a state of renovation of the sites that needs to be long-lasting to serve as the foundation for the network. So, carrying the backhaul infrastructure for 4G and 4.5G to 5G calls for multigigabits per second per site.”

One of the motivating factors for such high capacity is small cell development because the small cells extend the network further, and they require 100 Mbps to 200 Mbps of capacity per cell. Their traffic is aggregated to macrocells that eventually will have to have backhaul capacity of hundreds of Mbps, even 1 Gbps per site.

Yaniv said backhaul equipment providers must ensure that the infrastructure can adapt to the capacity and latency required. Latency is the interval between initiating a transmission and receiving or detecting the result. Sometimes they need to adapt for the number of carriers they aggregate, referring to carrier aggregation of the backhaul, not wireless service carrier aggregation.

Besides the growing demand from macrocell backhaul these days, Yaniv said another step of renovation and innovation injected into networks motivates operators’ decisions to deploy new, modernized equipment at new sites and to renovate existing sites.

Although his company provides wireless backhaul equipment, Yaniv yields to fiber-optic infrastructure as the superior backhaul technology. “If you have the fiber in place, go for it,” he said. “That’s the best alternative.”

Yaniv said the problem is that fiber is not available everywhere. He cited the alternative cost and the time to market or time to revenue that operators need to achieve. That’s where Ceragon sees market differences from one country to another as reflected in market research. Although the United States has more fiber, Yaniv said many places remain where fiber doesn’t reach. “This is where you need wireless solutions to get connectivity in place for speed of deployment because it’s so competitive for wireless service providers,” he said.

Around the world, backhaul is 40 percent wireless and 60 percent fiber, Yaniv said. Ceragon is seeing fiber take an increasingly larger share, but he said the differences are only a few percent here and there. Seven years ago, the ratio was 45 percent wireless to 55 percent fiber. Wireless backhaul continues for the simple reason that fiber cannot reach everywhere. Yaniv said for operators in some countries, backhaul is 100 percent wireless. Some European countries make 38-GHz spectrum available nationwide for wireless backhaul, and they are looking for new spectrum.

“In the United States, there is more fiber, but it goes primarily into the major cities,” Yaniv said. “In rural areas, the story changes.”

For the long term, Yaniv said the market probably would remain around 40 percent wireless and 60 percent fiber, in part because a lot of wireless backhaul would be used to serve small cells. “When the closest fiber is across the street, operators have to consider what it takes to obtain a certificate from the municipality and then stop the traffic and dig that part of the street, together with the cost involved in the time spent,” he said. “It’s better to install wireless backhaul. You get the site up and running much faster.”

The Future for Backhaul

Yaniv pointed out that, for all the talk about upcoming 5G cellular technology, 5G has not yet been defined. “Nevertheless, there’s a vision out there,” he said. “What’s important for the service providers with 5G network infrastructure is operational efficiency. How do you make sure that you obtain the required capacity and low latency in a smart way that doesn’t increase operational costs? That’s one point.

“The other point is subscriber experience. The 5G subscribers are not only humans, they’re going to include many smart nodes that will consume data traffic and that have to be connected with ultra-low latency. How do you make sure that you have an infrastructure that can support hundreds of millions or maybe a billion smart nodes? That’s the operator perspective.

“Take this into the infrastructure from a backhaul perspective. How does the network operator deliver capacity over the backhaul, whether it’s wireline or wireless, to the right places at the minimum price and minimum operational cost? How do I make sure the infrastructure is adaptive and can be integrated into the telco cloud? It means backhaul equipment providers have to make sure it is possible to perform optimizations using self-defining network protocols over the network, and we have to make sure we place the right resources in the right area in a dynamic way. The backhaul industry has a lot to say, when it comes to making sure that the 5G wireless networks are built in a highly efficient way.”

Yaniv said that some fiber backhaul providers would say that fiber scales better or more easily than wireless backhaul. He disputed that assertion, saying, “The wireless backhaul industry has shown time and time again that whatever the required capacity on the access part of the network, the wireless backhaul industry scaled in a way that supports these capacities and latencies. For example, Ceragon is working on solutions that support ultrawide, 10-gigahertz channels in frequency bands as high as 110 GHz and 140 GHz. Thus, the wireless microwave or millimeter-wave industry has a lot to scale to ensure that we meet future demand because, from the operator perspective, it always will be a wireline and wireless backhaul industry.”

In conclusion, Yaniv said the scale with 4G deployments in the United States is such that people are talking about it already and are implementing carrier aggregations that affect the backhaul and, therefore, capacity. A second point he made is the need to ensure that completing the migration to an all-IP infrastructure in which legacy wireless access equipment fades away is done in a seamless way with no outages.

“My last point is that small cells affect macrocell backhaul because they will introduce additional capacity requirements for macrocells,” he said. “That’s another aspect of development for the macrocells and for macrocell backhaul, in particular.”

This article originally ran in the July issue of AGL Magazine.