RAD Data Communications will showcase at the LTE World Summit 2013 (24-26 June, Amsterdam), a new Grand Master function, which can reduce the cost and complexity in LTE and LTE Advanced backhaul. Distributed GM expands the mobile backhaul solutions from the Service Assured Access portfolio of RAD and provides a precise clock signal for micro-or femto radio base stations. Thus, RAD offers a simple solution for one of the biggest challenges in the operation of LTE networks.
“Distributed GM drastically simplifies the entire architecture of synchronization in LTE backhaul networks. This novel approach is an elegant alternative to the two existing solutions, much more complex and uneconomical methods,” says Ilan Tevet, Service Provider Line of Business head at RAD.
One of the usual solution is to install at each base station comprises a GPS receiver. However, this is inefficient in LTE networks, which will see the number of cell sites increases exponentially – this is especially true for micro-cell networks that cover much less area than 2G/3G base station. In addition, LTE base stations are much more compact than their 2G/3G counterparts and often do not offer enough room for a GPS receiver, either because there is no room or because there is no clear sky view to a satellite, or both. Beyond that is the simple matter of economics: Purchasing, installing and maintaining a GPS receiver at every LTE base station will quickly become prohibitively expensive.
The second current option for network operators is the use of a reference clock (Grand Master Clock) with IEEE 1588 functionality from a central location to transfer the timing information of the entire network to all backhaul remote base stations. However, this requires an upgrade of a high number of intermediate network elements to facilitate IEEE 1588 message propagation (via capabilities such as Boundary or Transparent clocks) in order to minimize end-to-end Packet DelayVariation (PDV, or jitter) and guarantee the high quality of synchronization required by LTE base stations.
Complexity drops drastically
“Distributed GM is already integrated into RAD ETX-2 Advanced Carrier Ethernet device which supports 1588 Grandmaster and is also equipped with a built-in GPS receiver,” Tevet explains. “Since the ETX-2 is designed to be deployed at the first aggregation point, closest to the cell-site or a cluster of small cells, it will not overcrowd base stations, and since it will typically be situated much closer to base stations than a Grandmaster clock would be, it can provide an accurate reference clock for the base stations with no network upgrade.”
Two functions in one unit
“RAD is the only vendor to offer a combined, compact solution for aggregation and synchronization in a single LTE backhaul device,” said Tevet. “The small form-factor ETX-2 eliminates the need for two separate boxes that otherwise would be needed to provide the same dual functions, reducing both CapEx and OpEx and speeding up ROI in the process,” he concludes. “Operators will find that Distributed GM provides an ideal Service Assured Access solution for the challenges presented by LTE backhaul.”
Also decrease the cost of commissioning
“Although micro-cell architectures were in the forefront of the discussion so far, still did not find the requirements for extremely high clock synchronization accuracy and for a variety of small mobile cells have enough attention,” says Glenn Hunt, principal analyst at Current Analysis. “RAD distributed Grandmaster solution addressed in this context not only the technical requirements but also the cost optimization of the rollout.”
RAD customers include operators and service providers such as Bharti Airtel, British Telecom, CenturyLink, China Mobile, China Telecom, Deutsche Telekom/T-Mobile, Embratel, France Telecom/Orange, Hutchison, KDDI, KPN, SingTel, SoftBank, Telefónica, Telekom Austria, TeliaSonera, Telstra, Telus, Verizon, and Vodafone.