Fujitsu mobile WiMAX SoC supports femto, pico and micro base stations

Meeting the narrow cost constraints of a femto environment, while scaling one solution to pico and micro base stations was a challenge eluding system manufacturers and service providers. Fujitsu's mobile WiMAX base station SoC targets all three base-station platforms with a single SoC. This results in system manufacturers being able to leverage a single core solution across several small base station platforms.

"For the femto base station, we're targeting prices for the end user of under $100," says Dean Chang, Fujitsu senior product marketing manager. "And, it's scalable to pico and micro stations as well. The advantage for system manufacturers is that they can leverage this single platform as a single core across multiple base station platforms," Chang added.

What the SoC targets is widespread wireless churn based on poor coverage in homes and buildings. Approximately 70% of traffic is indoors, yet at 2.5GHz, a significant attenuation loss occurs through exterior walls. The frequencies for WiMAX and other 4G technologies are much higher, resulting in even more loss. Capacity is also growing--Internet traffic is doubling every 12-15 months even on mobile devices and IP TV and media downloads are consuming substantial bandwidth. High speed demand is great. The challenge is that at the micro base station, as signals go through an exterior wall, they operate at a lower modulation rate which effectively means lower bandwidth for everyone. Small base stations can actually add capacity to take on some of the burden and improve the voice and data results.

The SoC can be designed into femto base stations for indoor applications; into pico stations for indoor or outdoor applications by service providers or enterprise networks; and into micro base stations for outdoor use by service providers.

The Fujitsu solution incorporates all PHY and MAC features, analog and digital radio control, and analog circuits required to conform to Wave 2. A dual-integrated ARM core at up to 360MHz provides the processing power at a femto base station. For larger platforms, an additional processor can be connected by means of a PCI host interface to handle demands for more throughput and a bigger user base.

The SoC provides a 10/100/1000 Ethernet interface, along with a DDR-II and flash memory interface and a full range of peripherals including UART, DMAC, timer, GPIO, SPI, I2C, low-speed ADC/DACs and a network synchronization interface. The power requirements are approximately 2W, typically enabling a full femto base station to operate on less than 10W.

Fujitsu offers a femto base station reference design kit. Incorporated features include the Wave 2-compliant Mobile WiMAX PHY and MAC feature set, RF (2X/2X MIMO), Ethernet, GPS and IEEE 1588 for frequency and timing synchronization, and location ID. The reference design kit also includes an R6 interface to an ASN gateway.

The SoC comes in a 676-pin BGA package. The reference design includes all required software and hardware for ODMs or contract manufacturers to build a cost-effective system solution.