Canadian carriers prepare for the ‘backhaul bottleneck’

Mobile service providers have high hopes that novel applications and services will help drive up subscriber numbers and revenue, but some industry observers say a problem threatens to bite wireless carriers in the backhaul. In recent years, service providers have enticed users with rich and bandwidth-intensive applications, such as video calling, picture and video messaging in addition to email. But these interactive services could overpower the carriers' backhaul networks - the connections from network end points (cell towers) back to the network core, where calls and data streams are routed to their destinations. And with an increasing number of wireless subscribers sending email, photos and files from handheld devices, backhaul networks could be overwhelmed, causing slow service, interrupted communication, and unhappy customers. While the problem is more acute in other parts of the world where wireless penetration is higher and subscribers use their devices for more bandwidth-intensive applications, carriers in Canada are taking notice. Bell Canada is well aware of the potential problem. "It's the way you engineer the network that really counts," says Stephen Howe, senior VP of wireless networks. Bell uses a mix of T1s, fibre, and microwave connections to support backhaul traffic on its network. To avoid a single point of failure, the firm eschews series connectivity in favour of hub-and-spoke and star network topologies, so if one link in the backhaul failed, the disconnection wouldn't spell loss of service across the entire infrastructure. "All carriers do have to watch out for it," Howe says, explaining that new services such as the company's NHL Centre Ice Mobile spell new backhaul network pressures. Unveiled this month, the service lets hockey fans watch or listen to games live on their smartphones. Exclusive to Bell, the content could attract quite a following, and the resulting rush of requests for access to the games could cripple the backhaul network if it isn't engineered to withstand the onslaught. "The transport engineers have to stay a step ahead of that," Howe said. Rogers Communications also tries to be in front of network bottlenecks with smart network engineering, according to Arnold Abramowitz, senior director of network quality. Rogers uses a mix of fibre and microwave to meet the demands of services such as Rogers Vision, which includes video calling. While Vision is optimized for wireless, "the challenge will come from services that are much more data heavy than video calling," Abramowitz said. "You have movie clips, YouTube applications, straight downloads as well....They tend be heavier." But which network technologies make the best backhaul solution? While fibre is the bandwidth king, it's also relatively expensive to install, so it's not an option for less-populated parts of the country, where the return on investment would take forever. Copper connections are ubiquitous, but they don't provide enough capacity to satisfy future backhaul requirements. Companies like BTI Systems and DragonWave sell backhaul solutions based on microwave infrastructure. According to Alan Solheim, DragonWave's VP of product management, wireless systems such as those his company offers are particularly cost-effective for Canadian service providers, because carriers in this country don't yet require the multi-gigabit capacity of fibre-optics in the backhaul. "Base stations, even at the most, require a few hundred megabits," Solheim said, adding that microwave solutions offer a lower cost-per-megabit compared to fibre. But if the base stations do require gigabit-plus connectivity, microwave might not be the best answer. DragonWave's systems top out at 1.6 Gbps. And while the company continues to work on higher capacity products, Dragonwave isn't there yet. Duncan Stewart, director of technology, media and telecommunications research at business consulting firm Deloitte Canada tells Report on Wireless it's hard to tell if microwave or fibre will win the backhaul battle. "It's really too early. This wasn't a problem for years." Other factors come into play as well. For instance, consider femtocells. These miniature base stations designed to boost mobile connectivity in office buildings and homes could increase the pressure on the backhaul infrastructure even more, Stewart says. "You have the potential of people doing a lot more uploading. They're wonderful, but I'd be afraid to think about what they'll do to backhaul networks," he says. So what should carriers do? Stewart notes that in today's economy, "it's difficult to tell wireless carriers to go out and over-engineer a system by factor-X. Throwing money at the problem is definitely not the answer." Instead, service providers need to put a modern spin on an old adage: measure twice, cut once. "It's not about buying new technology," Stewart says. "It's about spending on incredibly thoughtful system engineering before you plug anything in."

Canadian carriers prepare for the ‘backhaul bottleneck’

News | 01/19/2009 2:56 pm EST

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