Remote radio heads ease WiMAX deployment

MIMO remote radio heads are available for both 2.5 and 3.5GHz networks, and can be customised to meet the specific OEM interface and packaging requirements.

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 2.5 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 multigigabit BTS connections, communicating via OBSAI, CPRI or custom OEM fibre interfaces.

Axis RRH models are available for use in the 2.3-2.7 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 IEEE802.16d/e standards.

They are also capable of four-channel MIMO operation using two-channel units driven separately from OBSAI/CPRI or daisychained.

Channel bandwidth is variable between 3.5 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 predistortion, 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 one or two 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 two-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 basestation, thus reducing opex.

"Using a distributed remote radio head design triples basestation efficiency, which not only makes them around 60% cheaper to run but also makes them a greener option", commented Simon Mellor, CEO of AxisNT.

"The flexibility in deployment that results from using fibre optic cables rather than RF cables reduces the basestation footprint too, meaning lower site rental costs for the operator and a further reduction in environmental impact".

A standard RRH implementation involves a close co-operation 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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