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Axis Network Technology Launches MIMO Remote Radio Heads

Axis Network Technology (AxisNT) has announced the immediate availability of a family of MIMO Remote Radio Heads (RRH) for OEM deployment of WiMAX networks worldwide. The RRHs are available for both 2.5GHz and 3.5GHz networks, and can be customised to meet the specific interface and packaging requirements of the OEM. Designing WiMAX basestations using a distributed RRH approach with highly efficient digital-to-RF conversion and amplification considerably reduces both CAPEX and OPEX of the overall system as well as maintenance costs.

The use of an RRH allows the radio to be located alongside the antennas and physically separate from the basestation (BTS), removing the losses associated with long cable runs by replacing them with an optical fibre data interface. The AxisNT RRH presents flexible multi-gigabit BTS connections, communicating via OBSAI, CPRI or custom OEM fibre interfaces.

Axis RRH models are available for use in the 2.3 – 2.7GHz and 3.3 – 3.8GHz spectrum bands, and Axis radios are configurable for frequencies between 400MHz and 4GHz. Each of the models offers dual channel operation for MIMO, to comply with WiMAX and IEEE 802.16 d/e standards. They are also capable of 4-channel MIMO operation using 2-channel units driven separately from OBSAI/CPRI or daisy chained. Channel bandwidth is variable between 3.5MHz and 20MHz for TDD or FDD air interfaces.

Employing high efficiency advanced power amplifier technologies, the RRH units are available in several options with downlink output power levels of up to 28W . The advanced power amplifier design features include PowerDPD Digital Pre-Distortion, digitally controlled Doherty amplifiers and flexible wideband crest factor reduction (CFR).

The RRH also feature automatic calibration of transmit, receive and PA bias control loops, and are fitted with OBSAI RP3-01 or CPRI V2 digital baseband interfaces with either 1 or 2 optical connectors as required. They integrate an AxisIPR configurable IP radio processor, along with an AxisOS remote management and local craft interfaces. Support for Adaptive Antenna Systems (AAS) and AISG v2.0 antenna control is provided.

Superior receiver performance of better than -98dBm can be achieved with single channel operation, and better than -100dBm using MIMO. A distributed BTS using 2-channel RRH with 28W downlink power is the equivalent of transmitting 56W downlink power from a traditional ground based BTS (assuming 3dB cable losses). Power consumption is reduced to a fraction of a traditional base station, thus reducing OPEX.

A standard RRH implementation involves a close cooperation between the customer and the AxisNT engineering team, to perform interoperability on the OBSAI and/or CPRI digital interface implementation. Products are available with a variety of interface connector options, with a single or dual fibre optic interface for up to 10km of FO cables, a choice of compact and lightweight packaging, and they can also be fitted with an optional customised solar shield. The RRH are optimised for low power consumption and feature a wide input voltage range to provide flexibility in site installation. A built in handle and a variety of mounting brackets allow ease of installation. Additionally AxisNT will customise its RRH for the specific requirements of OEM customers, in respect of connectors, packaging and labels.



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