Atheros speeds up cheaper wireless devices
Atheros has announced a series of Wi-Fi chipsets which it has dubbed "Align". Atheros says they operate in accordance with the IEEE draft 802.11n specification using a single spatial data stream ("1-stream"). This requires just a single transmitter/receiver and a single antenna (Single Input Single Output or SISO) and achieves a data transfer rate of up to 150 Mbps. Current draft-N components using MIMO use up to three antennae and currently achieve a maximum speed of 300 Mbps. Some laptops already use three streams to achieve speeds of up to 450 Mbps, but are hampered by the fact that there are no compatible base stations available yet.
According to Atheros, Align chips occupy the wireless channel for shorter intervals than comparable 802.11g products, preventing congestion and creating more capacity for additional wireless devices. Space Time Block Coding (STBC) and Enhanced Receiver Synchronization (ERS) should double transmission range compared to 802.11g. If device manufacturers include an extra receiving antenna, the Align series can use Signal Receive Combine (SRC). Atheros has also included a number of energy saving features, such as Efficient Power Amplifier (EPA), Wake-on-Wireless and Unscheduled Automatic Power Save Delivery.
Atheros is aiming the Align series at cheaper laptops and netbooks or multimedia devices such as media players. The single chip AR9285 (PCI-E) is intended for laptops. The AR9002AP-1S chipset is intended for driving wireless routers. It consists of a wireless "AR9285 1-stream" module (MAC/BB/Radio) and the AR7240 system-on-a-chip (SOC consisting of a network processor and 5 port switch). Its MIPS32 core runs at 400 MHz, which, according to the vendor, is sufficient for interacting with MIMO capable wireless modules. Finally, the AR9271 (SOC with USB) is intended for use in set-top boxes, games consoles and printers. Samples of the AR9002AP-1S and AR9285 are already available; mass production of the AR9271 should commence in late 2008.