/> As a leading vendor in the WiMAX arena, Airspan offers a complete family of base stations and end-user premises equipment. Its top-of-the-range product is the powerful HiperMAX base station, which today offers both fixed and mobile WiMAX capabilities including a software-only upgrade for carriers who have already deployed the former solution.
During the early development phase of HiperMAX, Airspan decided that the flexible, modular architecture of a standardised AdvancedTCA (ATCA) chassis would not only provide economies of scale but also ensure that the product reached the market as quickly as possible.

Airspan’s Vice President of Product Management, Paul Trubridge, takes up the story: “We knew that the customers we had in mind for HiperMAX would be familiar with ATCA technology and its ability to deliver high-availability, redundant solutions. So it made much more sense to go down that route, rather than starting from scratch and developing a totally proprietary system.”

Schroff’s electronics packaging capabilities were already well known to Airspan, since the company had previously supplied large quantities of its multipacPRO 19in. chassis for one of Airspan’s earlier base station models.

When Airspan enquired about possible ATCA systems, Schroff was able to offer a choice of fully assembled standard configurations consisting of subrack, guide rails, backplane, cooling units and power entry modules. In line with the requirements of the PICMG 3.0 Rev. 2.0 specification, these standard Schroff ATCA systems were all designed to accept rear I/O boards and therefore had a depth of around 400mm.

“However, WiMAX base stations are often located in secure telecoms equipment rooms where space can be restricted,” continued Trubridge, “and we actually had a customer requirement for a reduced depth with front access only.”

Reducing the depth would help to minimise the base station’s footprint, and having the back of the unit closed would mean that it could be installed without leaving space for rear access – for example, against a wall.

In the light of these requirements, Schroff’s engineers set about modifying the design of the 5-slot and 14-slot ATCA systems that Airspan had chosen for the two versions of its HiperMAX indoor carrier-grade base station. Working closely with Airspan’s development team, Schroff removed the rear I/O facility and transferred the power modules to the front of the units, thereby enabling the chassis depth to be reduced to the required depth. The redesigned systems were then subjected to thorough EMC and thermal testing to ensure that they complied with the relevant international standards.

Airspan’s Trubridge again: “Schroff was very responsive to our special requirements, and our decision to use the ATCA chassis certainly freed us to concentrate on the design of the baseband blades. This enabled us to launch HiperMAX considerably earlier than would have been possible if we had designed the whole system from scratch.”

The 5-slot HiperMAX base station typically has three baseband blades - one for each radio sector – while the 14-slot version can accommodate up to 12 baseband blades and includes the capability to deploy redundancy. Since its launch, the HiperMAX base station has been used in numerous deployments worldwide.