Mid-band Ethernet is ready for its close up now, but that close up might not be where you were thinking. True, metro is the place to be these days, but mid-band Ethernet is also making a name for itself where it could be needed the most—cell tower backhaul.

With everyone and their Aunt Betty using their cell phones to not only make calls but also take and send photos, send emails, download from iTunes, organize their schedule, text message, take videos and watch their favorite TV shows, the cell phone is becoming a true multimedia device.
But this rapidly evolving technology is putting immense stress on the network, and many providers are finding that while there is a glut of fiber in the network core, they are left out in the cold with the lack of fiber available for cell tower backhaul. This lack of fiber to the tower results in dropped calls, packet loss, voice call quality degradation and more.

As a result, some wireless providers are turning back to copper for backhaul, using mid-band Ethernet to replace T-1s and getting more bang for the buck thanks to the technology’s affordability, resiliency and capacity with its ability to offer over seven times the speed of a T-1.

Despite this increasing demand for multimedia wireless services, the problem is that fiber only reaches 2% to 10% of cell towers today and the growth of fiber deployment in this area is just 2% per year. When faced with the increasing demand for cell phone multimedia services and the growing number of people who use their mobile phones as their main communications devices, service providers should be concerned.

Because pulling fiber to cell towers is cost-prohibitive and sometimes impossible based on geographical and climate barriers, carriers today are looking for a powerful, cost-effective means to leverage the existing copper backhaul infrastructure to achieve the expandability and bandwidth that was previously only available from plowing in fiber.

Currently, third-party tower operators and service providers place towers based on demand and proximity to a stable, growing population—not on their proximity to fiber or based on existing wireless technical backhaul capabilities. This presents an obvious challenge for the service provider. The good news, though, is that copper is everywhere, and service providers can take advantage of all its benefits if they look at mid-band Ethernet as a backhaul tool instead of traditional T-1s.

Today, backhaul is a major expense for service providers, and according to analyst firm Communications Network Architects, last year, wireless carriers were spending over $2 billion on cell tower backhaul because of video, mobile broadband service assurance and next-generation IP multimedia subsystem (IMS)-based IP applications.

One provider, MTS Allstream, found itself faced with the backhaul problem as it began to roll out its EV-DO services to its customers across Canada. The demand for EV-DO was so high that MTS Allstream soon found itself stuck with too much traffic and not enough backhaul capacity. T-1-based technology could not effectively address the increasing bandwidth demands and provide MTS Allstream with the service performance it needed to support its growing mobile data business.

After researching alternatives, MTS Allstream wanted to leverage their existing Ethernet gear already in the network and began using mid-band Ethernet for backhaul as well, even to reach their most remote towers located in Winnipeg, the harshest of Canadian wilderness environments.
Not only was mid-band Ethernet able to withstand -50ºC temperatures, but also the ice, wind, snow and rain without outages because mid-band Ethernet is inherently more resilient thanks to copper bonding technology. Mid-band Ethernet bonds up to 8 copper pairs together to form a high-bandwidth connection of up to 45 Mb/s. When a pair fails, that pair is detected and removed from the aggregate in just a few milliseconds. Established connections remain operational, and the callers don't even notice that a problem has occurred. Applications, and their users, will not be able to detect that one of the pairs has failed except by the loss of some available bandwidth. When that pair comes back online, it is seamlessly added to the aggregate, and that again goes unnoticed by the applications and users. With T-1s and NxT1 solutions, however, if any of the pairs go down, service goes down right along with it.

In the past, service providers have had valid concerns about copper based on their experience with unreliable T-1s, especially when it comes to meeting bandwidth requirements and network monitoring capabilities.

Today’s mobile operators are looking for approximately 6 Mb/s to 30 Mb/s of bandwidth to each site, which is the bandwidth equivalent of four to 16 T-1s. In addition, the access portion of the network is one of the weakest parts in mobile reliability. Towers also have a resynchronization phase—which can wreak havoc on voice calls and data and video if the backhaul facility goes down. To top it off, mobile operators have had limited visibility to access network problems when it comes to T-1s.
But with innovations in mid-band Ethernet and the new Ethernet OAM standards, service providers can kiss these concerns goodbye. The copper technologies available with mid-band Ethernet today have significantly improved over T-1s. Mid-band Ethernet can offer seven times the bandwidth and over 13 times the throughput of a T-1. Mid-band Ethernet is also significantly more cost-effective per Mb/s than T-1s, and the multiple pair bonding technique offers providers the reliability that they’ve been lacking with current T1 technology.

Network visibility is also improved with mid-band Ethernet thanks to the new Ethernet OAM standards, which enable service providers to proactively monitor and know service degradations and failures consistently across Ethernet access.

Mid-band Ethernet isn’t just for cell tower backhaul, though. Service providers can benefit from its resiliency and affordability for other backhaul applications, including DSLAM backhaul, WiFi/WiMAX backhaul and redundancy for fiber transport.

With the burgeoning deployment of public and private wireless data infrastructure, WiFi at 52 Mb/s with 802.11g, and WiMAX on the horizon, there exists an increasing need for backhaul of the data from rooftop to point of presence.

With 802.11 wireless mesh networks, there are typically two rooftop to point of presence terrestrial backhaul facilities required for every square mile. Mid-band Ethernet provides a bandwidth and cost-effective solution for broadband wireless data backhaul because a service provider can leverage existing copper in the riser to building rooftops and deploy an initial backhaul link over one or two existing copper pairs and then scale up the bandwidth as needed.

In the DSLAM backhaul area, residential triple-play services are driving carriers to deploy IP DSLAMs farther into the access network. While optical fiber deep into the access network is the ultimate goal, service providers need to be able to reach their customers quickly and efficiently. Here mid-band Ethernet Services are a natural complement to fiber-to-the-x (FTTx) deployments, delivering native broadband Ethernet links to IP DSLAMs without costly, long-lead-time fiber builds. Bonding pairs together to provide data rates up to over 200 Mb/s (bonding up to 40 pair) over a resilient link provides broader service area coverage, sooner, resulting in shorter time to revenue for broadband services.

Mid-band Ethernet is also beneficial for guaranteeing redundancy for fiber transport. Sonet/SDH rings, resilient packet rings and proprietary Ethernet protection switched ring protocols from various switch vendors are all means of providing redundancy and failover protection for the network core links. However, fiber access links to buildings are most frequently provisioned as spokes off the resilient core. Redundancy is limited to a parallel link provisioned along a second fiber pair in the same cable, perhaps not even that. For critical applications, with service level agreements (SLAs) allowing only minutes of downtime a month, this is not suitable. Mid-band Ethernet services offer an inexpensive means of providing electrical, physical and, perhaps, full-path diversity to the main fiber access facility with the guarantee of high-quality, end-to-end service.

Ethernet long ago won the office LAN and corporate campus environment, and now service providers are seeing the benefits of Ethernet in other areas such as backhaul, whether it be cell tower, DSLAM or WiFi/WiMAX backhaul. In our technologically advancing world, mid-band Ethernet services fill a huge gap in the service catalog today. They offer 2-45 Mb/s capacity at a price per bit below existing access services. They can be rapidly and cost effectively deployed over the existing copper access network, reaching over 95% of high value customers’ business locations. As a native Ethernet technology they are readily integrated into both enterprise networks and service provider metro networks, supporting end-to-end Ethernet switching, class of Service, quality of service and performance SLAs. Operational costs are contained through the use of existing Ethernet operational capabilities, training and support systems. Service providers can package high-margin mid-band Ethernet services for the last mile into high-value, end-to-end solutions that attract customers based on performance and price. Lastly, the flexibility to boost the speed of Mid-band Ethernet services in response to future customer requirements will result in incremental service revenues plus improvements in customer satisfaction and retention.