Are MNO backhaul plans broken?

22 November 2011 | Guy Matthews


Mobile operators will need to up their game if tomorrow’s increased traffic levels are to be handled. But is this a challenge they are in danger of underestimating, or one they are on top of? Guy Matthews reports.

   

A report from Juniper Research concludes that mobile network operators will need, cumulatively, to spend $840 billion globally over the next five years on optimising backhaul assets and adding capacity.

This is a far larger commitment than most will have budgeted for, fears the consultancy. It warns that operators need to revisit their plans for investment in backhaul networks if they are to have any chance of meeting fast developing customer needs, warns analyst firm Juniper Research.

Nitin Bhas, Juniper Research analyst and author of the report, says that rapid uptake of subscriber data services make it necessary for operators to immediately reassess their mobile backhaul requirements and ensure that future network infrastructure fulfills requirements.

So just how fixable is the problem? Even granted that next-generation standards like LTE are certain to add to network pressures, is backhaul really the mountainous challenge that Juniper suggests?

The key bottleneck
Mervyn Kelly, EMEA marketing director for equipment vendor Ciena, says that of all the capex commitments faced by MNOs, backhaul really does justify its reputation as the key bottleneck: "The backhaul network can be seen as the foundation for any successful mobile network strategy,” he says. “If you get it wrong, no matter what services you intend to offer, the network will not be able to cope.”

“The huge rise in data traffic is creating new challenges for mobile operators who must accommodate this explosion in demand,” agrees Gaby Junowicz, vice president of business development and marketing with Siklu, a vendor of backhaul solutions. “Meeting this in a way that creates revenues is a big hurdle to overcome. At present, revenues resulting from the data explosion are almost flat, offset by the cost of delivering the increased bandwidth needed for higher data throughput. As providers transition to new 4G and LTE sites, this conundrum – meeting demand for additional data services whilst protecting profit margins – will only become more serious.”

Carrier Ethernet-based mobile backhaul is, believes Ciena’s Kelly, the only viable solution currently on the table: “Ethernet is purpose-built to address this insatiable demand for more bandwidth, offering a cost-effective, flexible and scalable architecture that can be tailored according to customer needs. This means operators can control bandwidth growth costs while supporting next-generation services such as social networking, mobile internet and video streaming – opening the doors to the new revenue streams while proving the superior experience consumers demand."

But good backhaul, even good Ethernet-based backhaul, doesn’t come cheap, argues Tara Van Unen, senior manager of market development with vendor Ixia: “Mobile backhaul is one of the major contributors to the high costs of building out and running a mobile network – estimated to be approximately 25% to 30% of total operating expenses,” she claims. “As demands to support increased mobile data traffic grow, it is important that operators optimise their networks with the most cost efficient backhaul techniques. Operators are thus looking to move to packet-based backhaul techniques using IP and Ethernet to gain a lower cost per bit. Using Carrier Ethernet for wireless backhaul allows operators to support large bandwidth increases from cell sites, while keeping operational costs in check. Operators can significantly reduce their cost per connection by moving from TDM to Ethernet.”

Migration to LTE
Kamal Mokrani, global VP for sales and marketing for vendor InfiNet Wireless, agrees that migration from traditional TDM transport, adequate for a 2G and 3G network era, to packet transport for 4G LTE networks will have a significant impact on the backhaul transport segment: “[With LTE] the capacity bottleneck shifts from the air interface to the backhaul link between the base stations and the core network,” he claims. “LTE backhaul needs to be far more efficient and cost-effective whilst simultaneously satisfying operators and transport provider expectations for carrier performance, higher capacity demands, reliability and costs.”

Richard Brandon, head of strategy at backhaul specialist MLL Telecom agrees that the LTE era is set to make all the difference to the sheer scale of the problem: “It's safe to say that more mobile backhaul will be required at ever faster speeds to cope with the volume of data network traffic,” he suggests.

“LTE networks will require up to a gigabyte per second across microwave links. MLL Telecom is already conducting LTE backhaul trials with some of the network operators, based on their need to prove their networks’ readiness for LTE. But, it's not all about capacity. Throwing bandwidth at the problem is only part of the solution. Network operators also need to look at other ways to reduce congestion in the radio access network (RAN) caused by the increasing demand for internet video and other rich media mobile content. Mobile broadband optimization solutions which free up capacity in the RAN and maximise network performance, such as IQ Stream from Sycamore Networks, are needed.”

Richard Kinder, VP for technology and new business EMEA at vendor Red Bend Software, agrees that even with most MNOs still in LTE testing mode, now is the time for investment.

“According to Ofcom, the volume of data on mobile networks has increased by 104% in the last year,” says Kinder. “Whilst the majority of this traffic is driven by people with mobile broadband subscriptions, undoubtedly the new breed of data-intensive mobile devices contributes significantly to this rapid growth. This bandwidth consumption is stressing the edge of the network and backhaul, resulting in a potential field day for providers of optical and microwave infrastructure. I could successfully argue that the capacity crunch is already upon us. We cannot rely solely on network operators’ investments in infrastructure to address the capacity crunch. They need services and platforms that can help them manage their capacity concerns.”

Offloading mobile data
A frequently cited answer to congestion problems, says Kinder, is to off-load mobile data from the mobile core network. Various techniques may be deployed to achieve this, such as WiFi or femtocell offload, he says.

“The harsh reality is that meeting the needs of tomorrow’s mobile data user means getting greater access capacity into the network today and here there is a completely different backhaul issue that operators must address,” agrees Stephen Rayment, CTO at BelAir Networks. “In order to increase data capacity, many operators are looking at deploying small cell networks, where base stations are brought down from the rooftops onto the ground and mounted on street poles. However, in this scenario it can be difficult to get fibre or copper near all pole mounted small cell units.”

Hence, he says, it is small cells that really present the next backhaul issue operators must face in order to meet the needs of tomorrow’s data user: “Some vendors are proposing using a separate wireless or WiFi unit architected as either a P2P or mesh solution for small cell backhaul, whereby data is routed across access points until it reaches a conventional backhaul network,” claims Rayment. “The challenge here is that adding a separate backhaul unit for small cells means extra negotiation with the local council or utility for permission to place two boxes on a pole. This not only adds more time but more cost to small cell deployment.”

Ross Cassan, senior product marketing manager, Spirent Communications believes that addressing the infrastructure side of the backhaul problem is only part of any credible solution. He says testing of networks is key to understanding whether that can truly perform to a required level.

“Testing a network with a solution that reproduces anything less than a realistic environment is too risky,” he warns. “Mobile operators must minimise that risk by mirroring actual network scenarios and traffic patterns. By emulating high scale, realistic traffic, operators can ensure that networks and components are evaluated accurately and proven to perform. This approach ensures that IP and Ethernet-based mobile backhaul solutions offer the highest QoE while meeting continually increasing bandwidth demands and the associated synchronisation and timing requirements inherent to next-generation wireless networks.”

Bob Hockman, VP product management at Empirix, service quality assurance backs this claim, but adds that the all important factor of customer experience must also be working into the equation.

“One of the most difficult challenges operators face when optimising any portion of the mobile network is being able to truly understand its impact on customer experience,” he advises. “This requires an analysis of mobile communications not from a network performance point of view but from the perspective of the application as it is delivered to the customer. In other words, how well customers are able to watch YouTube videos, stream music or chat with friends. Obviously, a more holistic approach to service assurance is needed, one that correlates all services, network elements and protocols to provide a total picture of customer experience. Without complete visibility into customer experience, operators cannot effectively assess the effectiveness – and ROI – of any infrastructure investment.”

Steve Haines is chief operating officer with BT Wholesale, one of the big carrier names on hand to provide backhaul solutions for MNOs. Does he think that his mobile customers are on top of or behind the curve?

“Data growth will increase further, and all MNOs are getting ready for LTE,” he said. “We’re a key part of the journey for a lot of operators, having invested in high capacity Ethernet capabilities ourselves. Pure Ethernet especially will let them consolidate traffic at the level of the base station. We’ve got a lot of relevant experience of this sort of thing from the fixed network market. Data, after all, is data whether fixed or mobile. But have they underestimated what they need to do? Time, to be honest, will tell.”