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2013 Predictions: The addition of timing to mobile backhaul services

Editor’s Note: With 2013 now upon us, RCR Wireless News has gathered predictions from leading industry analysts and executives on what they expect to see in the new year.

As 2013 dawns, the unprecedented growth in mobile data traffic shows no sign of relenting. The rapid spread of lower-cost smartphones, the continuing “4G” build out and the consumer trends such as “life-logging” are a perfect storm that will continue to push networks to the breaking point. However, where some see angst, others see opportunity.

Shrewd network providers are rapidly leveraging the latest technologies to tap into this disruptive opportunity. It’s already a foregone conclusion that the only way to deliver enough mobile bandwidth, at acceptable price points, is through carrier Ethernet.
Yet, the migration of 2G and 3G mobile backhaul networks to carrier Ethernet has been, up until now, half-hearted at best. When a network is already running smoothly today, it takes a lot of willpower to change it to something you know will be needed tomorrow. Operators have finally hit the point to where the migration to carrier Ethernet is no longer a future-looking “nice to have.” It is now an imperative.

While a lot of the public and media attention goes to the tier-one mobile network operators, there is actually an entire ecosystem of vendors that all work together to deliver a mobile service. An MNO will seldom own all the networks between its core network and a tower site. This connection is provided by mobile backhaul providers, using carrier Ethernet to keep track of the end-to-end connection. The well-publicized MNOs’ “4G” build outs have quietly initiated an even larger expansion in mobile backhaul networks.

However, there are key differences in “4G” services that are challenging these mobile backhaul providers, the most prominent being the need for providing high-quality timing information. LTE needs accurate frequency and phase synchronization to work, and there are now far too many antennas for it to be economically viable to put a GPS clock source at each site. The solution is to simultaneously provide both phase and frequency information over the packet infrastructure, and there are two standards that tell how to do it. IEEE 1588v2 defines a precision time protocol (PTP) that embeds timing in packets and specifies how each node in line should handle the information. ITU-T G.8261/2/4 synchronous Ethernet (SyncE) defines how input and output signals can remain in frequency and phase lock when passing through an Ethernet device. While PTP requires only intermediate network nodes to be transparent to the information being passed, SyncE needs every node in the path to remain in a locked state. PTP and SyncE may be combined to yield even tighter timing. Implementing PTP and SyncE is fairly straightforward, as where legacy customer premises equipment does not support them, SyncProbes may be added in series or parallel with the existing network. With their move to carrier Ethernet, it appears that MNOs and mobile backhaul providers will also be relegating their legacy, synchronous-based timing and local GPS antennas to backup duty.

There is more to timing than simply delivering it, though. The quality of the timing must be assured. Service assurance refers to not simply selling a service, but monitoring it in real time to make sure that the service is meeting the customers’ expectations.

In this case, if mobile backhaul providers want to carry an MNO’s important customer traffic, they need to meet a mutually agreed upon service-level agreement. The same holds true for timing. A mobile backhaul provider cannot expect to sell timing to an MNO’s tower site unless it is able to write, monitor and meet a timing SLA.

2013 looks to be a good year for those mobile backhaul operators who have invested the time and resources to be ready for the challenge that “4G” backhaul brings.

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