Mobile network operators are in a tight spot. Their success in popularising 3G and 4G mobile services, while welcome for its upward influence on revenues, is leading to a rise in the bandwidth that needs to be provisioned to cell sites to handle backhaul.
While the intuitive solution might seem to lie in ramping up existing backhaul arrangements, this in reality is not an option. The sums don’t add up. The bandwidth sourced in future by MNOs needs to come in at a far lower cost per bit than it does now.
The problem is that existing backhaul strategies were formulated for networks engineered for a world of voice traffic: “The UK is just one example of mobile networks not built to cope with modern bandwidth demands,” says Emma Forrest, Ethernet product manager at Cable & Wireless Worldwide. “To cope with the data explosion, they are looking for a solution with easily upgradable bandwidth that’s also economical.” The answer, she says, is obvious: “With Ethernet, they get more for their money.”
Bob Walters, executive director of product marketing at AT&T Business Solutions, agrees: “The number of mobile customers is increasing, and so is the bandwidth needed per customer,” he says. “Wireless carriers need a solution for that, and to meet the data intensive world they find themselves in. All are tackling it differently, but all are agreed that the old DS1, DS3 world needs to make way for some sort of Ethernet solution, one that comes with the sort of SLAs they are looking for.”
Cost-effective solutions
Ethernet is not merely attractively cost-effective compared with alternative backhaul options, it is also more scaleable, allowing bandwidth to be provisioned in smaller increments without significant upheaval.
Furthermore it has a role to play in just about every part of a network, from cell tower to switching office or between switching offices, for customer access and mobile core. It works well with existing technologies, with Ethernet microwave one of the fast growing segments of the overall carrier Ethernet market. Fibre, copper and even cable also have their part to play in meeting backhaul needs.
Naturally one person’s problem is another person’s opportunity. There is a crucial role going forward for wholesale service providers, most of which are investing large sums in the sort of infrastructure that will offer relief to their mobile operator customers.
“We’re driving fibre to more and more cell sites, since with fibre-based facilities you can scale to where you want to go, right up to the 100Gb horizon, without a truck roll,” says AT&T’s Walters. “We’ve also expended a lot of energy on reinforcing our core network to make it resilient, strong and carrier-class, with redundancy and self-healing for the event of an outage.”
Equipment vendors too are mindful of the role they have to play in developing the hardware and software that will make a new generation of technologies, like LTE, work: “Lots of our customers are investing in network upgrades,” says Jay Greer, senior business development manager at ADC. “We’re talking, for example, to mobile operators about data-specific products that enable them to add value for their customers. There are very few technologies out there that can handle the level of traffic they’re talking about without being cost prohibitive. TDM is prohibitive when you’re looking at large volumes of data.”
Mobile data explosion
The mobile bandwidth challenge, says Greer, is set to grow even faster over the next few years: “By 2015, there are predicted to be five billion mobile subscriptions worldwide, with voice the least of operators’ concerns,” he says. “Carrier Ethernet is the backhaul method of choice here, unifying the control layer in a simple way, and enabling applications to be brought to market faster and at less cost. Where ARPU is an issue, you need to get applications out to market as quickly as possible to beat rivals. Look at the deluge of new applications that followed the iPhone, all of which demand manageability.”
“Everybody wants a slice of the mobile data explosion,” says Stephen Hateley, director of product marketing with Infovista, a developer of solutions for managing the performance of Ethernet services. “We’re talking to the carriers that are servicing the MNO. If you’re providing mobile operators with a wholesale service then you need to offer a service level that you can guarantee – and that’s about performance management. It’s about looking at the quality of service needed to support the next generation of traffic. It’s only going to increase – 2.5G, 3G, LTE.”
Standards
It’s not just carriers and vendors at work to resolve the pressure on mobile operators. The Metro Ethernet Forum has devised MEF 22, a standard specifically designed to explain how to apply existing MEF specifications to mobile backhaul. It provides a generic specification for Ethernet backhaul, including guidelines on architecture, equipment and operation.
“The new MEF standard for backhaul is tested and ready,” enthuses Jarrett Appleby, CMO at Ethernet exchange operator Equinix. “Meanwhile our role continues as an aggregation hub for the mobile operators.” Appleby agrees that carrier Ethernet is the only serious contender to resolve the mobile market’s future needs: “Ethernet is the great empowerer for backhaul,” he says.
