FAQ X-RAN

What evolutions will EBlink provide to its current CPRI compliant products in order to support the future fronthaul standards ?

The standards group are working on a new set of fronthaul specifications based on a so-called “7-2 functional split” that redefines the functions performed by BBUs and RRUs. One of the main difference is the format of the IQ samples carried over the interface in frequency domain as opposed to the time domain. In addition, those standards are also expected to be based on an Ethernet protocol.The working principle of the current products are not affected by this new interface: EBlink is therefore planning to adapt its existing CPRI interface products to support this new format.

What efficiency gain will EBlink’s future products provide compared to other solutions ?

EBlink’s FrontLink products have been demonstrated to offer an unsurpassed spectral efficiency for CPRI applications: for instance, a 45 MHz duplex is all that is required to support a LR5 CPRI channel in the 5.8 GHz band using both H and V polarities. Similarly, a pair of 50 MHz microwave channels could support two 20 MHz 4T4R MIMO LTE carrier using both H and V polarities equivalent to transport a CPRI 10 Gbps flow. In addition to ensure BBU-RRU interoperability, the new 7.2x functional division allows interfaces to reduce the bandwidth requirements of fronthaul signal transport by a ratio of 3. On this basis, EBlink’s technology offers an additional gain in spectral efficiency.

What about interoperability ?

The original CPRI standards were not designed as interoperable specifications. With the emphasis now being put on interoperability by the XRAN and ORAN organizations, EBlink anticipates a much smoother process and a richer ecosystem. EBlink’s upcoming wireless fronthaul solutions will reap the benefits of greater interoperability via quicker time to market and a richer set of interoperable equipment. Participation in XRAN/ORAN plugfests or PoCs could be a way to ascertain compliance with the new standards, without having to resort to private testing with other vendors. What capacity will upcoming EBlink product be able to support ? EBlink understands that the LTE industry requires more and more 10 Gbps CPRI interfaces (Line Rate 7) in order to support multiple LTE carriers up to 20 MHz and 4T4R and 8T8R MIMO (for instance a 10 MHz 4T4R carrier requires 2.5 Gbps and a 20 MHz 4T4R carrier requires 5 Gbps). Therefore, EBlink’s upcoming CPRI modules will provide support for those capabilities using a CPRI interface as a first step (he current generation of FrontLink products can support up to LR5 – 5 Gbps – capabilities). Support for CPRI LR7 will be offered in the future. As the new standards based on eCPRI and the new 7-2 functional split becomes accepted, EBlink will adapt its modules to support the new interface formats) and with similar RAN bandwidths (i.e. to support the same LTE/NR capacities in terms of MHz).

When will these products become available ?

EBlink has been selling its wireless fronthaul products and modules based on efficient fronthaul technology and is in the process of integrating this technology into other wireless vendors equipment.   EBlink plans on shifting its priority to developing its first module conforming to the new XRAN 7.2x after the publication of the 3GPP standards for this interface.  EBlink and its partners will continue to monitor the progress of standards development as well as, importantly the status of interoperability conditions for fronthaul and RAN products.