Vendors Dig In to Mobile Backhaul

With wireless networks evolving to support more, and more bandwidth-intensive, applications and the ongoing drive to control operational expenses, moving from T1/E1 to Ethernet connections for mobile backhaul has become a no-brainer. That helps explain why everybody and their brother at NXTcomm was hawking gear that addresses this application.

Wireless backhaul is one of the key applications addressed by Turin Networks’ new PDH-based Ethernet over Copper card for the Traverse Multiservice Transport Switch, which the company showcased at NXTcomm. The product allows service providers to migrate their base stations to Ethernet for the long term and enables cellcos to fill more efficiently the T1s they use for backhaul today (and may be locked into contracts for well into the future) by employing Ethernet muxing, explained Ralph Santitoro, director of Carrier Ethernet solutions at Turin.

Santitoro added that containing operational expenditures has become a key focus for wireless network operators such as Sprint and Verizon Wireless given they are shifting to flat-rate packages, and therefore need to maintain their margins. And, he added, better utilizing existing T1s can mean significant savings for a cellco. For example, Santitoro explained, a mid-sized mobile operator with 10,000 cell towers who pays $500 per month for a T1 per base station for backhaul can save $60 million if it defers investment in an additional T1 investment for each cell tower for just one year.

Mobile Factoids

Source: Actelis Networks

Meanwhile, Actelis Networks and RAD Data Communications at the show both unveiled pseudowire products for wireless backhaul.

Eric Vallone, Actelis Networks’ vice president of marketing, said that while legacy backhaul is inadequate for the new bandwidth-intensive needs of the wireless network, fiber deployments are limited and expensive to install. That’s why Actelis has tackled this service provider requirement with a copper-based Ethernet backhaul solution, which it calls the ML650 Ethernet Access Device for Mobile.

And while the ML650, which is compliant with MEF 8 and 18 standards, allows service providers to migrate to Ethernet-based backhaul, it retains the ability to support TDM circuits and delivers the highly reliable timing that wireless operators now rely on from their legacy backhaul connections, said Vallone.

RAD Data’s IPmux-216 supports a range of pseudowire flavors including TDMoIP (RFC5087), CESoPSN (RFC5086), SAToP (RFC4553), and HDLCoPSN (RFC4618). The product also converts up to 16 T1/E1 TDM data streams into packets for transport over Ethernet, IP and MPLS networks and provides SFP-based fiber or copper Ethernet interfaces that support Fast Ethernet and gigabit Ethernet.

Carrier Ethernet - Timing Is Everything

But it is the super accurate timing of the IPmux-216 that Eitan Schwartz, vice president of Carrier Ethernet technologies at RAD Data, emphasized in discussing the product with xchange. RAD engineered into its ASIC-guaranteed accurate timing and support for multiple clock domains over Ethernet. This allows transport providers to utilize their fiber by backhauling mobile traffic simultaneously from different cellular operators, with each one being able to rely on its own clock to guarantee synchronization.

Schwartz explained that base stations use the T1 clock from traditional backhaul solutions for RF references for cell phones. Now, with the IPmux-216, RAD Data enables base stations to do the same with Ethernet backhaul solutions.

“With pseudowires, you replace T1s, so you need to make sure timing looks and feels like traditional T1,” he said, adding that the IPmux-216 also allows for in-band facility loopbacks for circuit testing.

That said, it’s no surprise that timing company Symmetricom also is moving on the wireless backhaul opportunity.

T1 and new Ethernet backhaul connections need to have precise timing because the wireless network relies on that timing for handoffs, to prevent interference between base stations and just to deliver better signals in general, said Rajen Datta, Symmetricom’s senior director of product management.

Unlike some of the other wireless backhaul solutions on the market, Mike Vizzi, a Symmetricom product manager, said his company’s solutions are standards-based. They employ the IEEE’s PTP (Positioning Time Protocol), also known as 1588, he said.

Since the PTP standard was ratified in March, there has been a groundswell of announcements from various vendors, said Vizzi, but Symmetricom was the first to announce such a product, which is called the Grand Master. That product, which can serve dozens to thousands of client devices, was announced at CTIA. However, in early June, Symmetricom unveiled the TimeProviderT 500, a 1588-compliant access timing device that enables existing wireless base stations (GSM/UMTS) to use next-generation IP-based backhaul (such as Gigabit Ethernet), and not be tied to T1/E1 lines for their synchronization needs. The newer product will be generally available in August at a list price of approximately $1,000.

Datta said that while most wireless network operators still rely on T1s, he expects early deployments of Ethernet-based wireless backhaul to take off in the next six to 18 months.

But a few pioneers are doing Ethernet wireless backhaul today. In fact, wholesale provider FiberTower at NXTcomm received an EoS Award for its Ethernet Wireless Backhaul Service for 3G/4G (WiMAX/LTE). This new service was enabled by Accedian Network's Ethernet demarcation units.

Accedian Networks’ EtherNID Ethernet demarcation units establish MEF standards-based OAM over any network topology, while providing advanced service assurance functionality that includes Layer 1-4 loopbacks, continuous end-to-end SLA monitoring, in-service throughput testing and micro-second resolution one-way delay and jitter measurements. They are also cost efficient and highly scalable, capable of monitoring point-to-point, multipoint and mesh network topologies used in wireless backhaul applications.

Related Article:

NXTcomm Welcomes ‘Carrier Ethernet 2.0’

Related Webinar:

New Architectures to Drive Down Mobile Backhaul Costs -- sponsored by Ciena and xchange magazine

Share this article: Email, Slashdot, Digg, Del.icio.us, Yahoo!MyWeb, Windows Live Favorites, Furl
Add this article feed to: RSS, My Yahoo, Newsgator, Bloglines