Archive Index (1999-2012) | 2013-current at | About  

Linux powers 108Mbps MIMO OFDM Wi-Fi demo

May 31, 2005 — by Henry Kingman — from the LinuxDevices Archive — views

[Updated Jun. 1, 2005] — Cavium and Airgo are demonstrating a hardware/software reference design for 108Mbps wireless broadband gateways at the Computex tradeshow this week in Taipei, Taiwan. The design includes embedded Linux, Cavium's MIPS32 Nitrox Soho security processor, and “True MIMO” wireless cards from Airgo. It targets SOHO (small-office, home-office) and SME (small, medium enterprise) broadband wireless routers.

(Click for larger view of Cavium/Airgo Soho reference board)


Airgo claims to be the only company actually producing chipsets based on MIMO OFDM (multiple input, multiple output orthogonal frequency division multiplexing), which it says is a technique that has been “designed into all major proposals” for a next-generation 802.11n wireless LAN standard. The Cavium Soho reference board includes a mini-PCI slot that accepts an Airgo True MIMO card.

Airgo's True MIMO cards support multiple antennas, and use a technique known as “spatial multiplexing” to increase signal range and network throughput. “By leveraging multipath reflections of a radio signal, and transmitting multiple signals in a single 20MHz radio channel, Airgo's True MIMO multiplies both data rates and reliable coverage area without using additional frequency spectrum, and without causing interference with other Wi-Fi devices and networks,” the company claims.

Cavium's Nitrox Soho chips

The Cavium/Airgo reference design is based on one of the less expensive network processors in Cavium's extensive range of NPUs (network processor units). The design supports all five models in Cavium's “Nitrox Soho” line.

Cavium's Nitrox Soho chips are based on MIPS32 4Km cores, and support up to three Ethernet ports. They can process between 20 and 140Mbps of traffic, and are priced from $10 to $25, according to Product Manager Eric Dudley.

The Cavium/Airgo reference design includes a uClinux 2.4.20 kernel that Dudley says the company developed in-house, based on enhancements to the opensource 2.4.20 kernel for the NITROX Soho.

Cavium previously partnered with MontaVista on Linux support for the Nitrox Soho. Cavium also partnered previously with MontaVista and LinuxWorks on Linux support for other NPUs, including the multicore Octeon.

Nitrox Soho chips were used in a family of Linux-based wireless gateways launched by Sofaware in February.


The Cavium/Airgo reference design includes binary drivers for the Airgo cards, available with a source code license. Dudley declined to specify pricing.

This article was originally published on and has been donated to the open source community by QuinStreet Inc. Please visit for up-to-date news and articles about Linux and open source.

Comments are closed.