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Thursday, January 12, 2012

A Universal Chip for Cell Phones

A single chip for wireless devices that's multifunctional, more energy efficient, and space saving is in the works.

Research out of the University of California, Los Angeles (UCLA) has shown that a single wireless chip -- call it the "universal" chip -- could be in cell phones, as well as other wireless gadgets, in as few as three years, extending their battery life, allowing for sleeker designs, and permitting them to access features beyond Wi-Fi, GPS, global phone service, and Bluetooth.

A prototype for the "receiver" portion of a "universal" wireless chip that can receive radio frequencies ranging from 800 megahertz to 6 gigahertz -- which could eliminate the need for multiple chips inmobile devices, extend their battery life, and make them smaller. (Photo courtesy of Asad Abidi, UCLA.)

Today's cell phones can contain up to six wireless radio chips, which send and receive information in the form of electromagnetic waves. Each chip has a specific function: there's one designed to work at the frequency of the cellular carrier's signal and others for Wi-Fi, GPS, and Bluetooth frequencies.

Historically, engineers have designed these chips to work within only a small range of frequencies in the radio spectrum. For instance, in order to communicate with a cell-phone tower, a chip may be optimized to send and receive information at 900 megahertz (or another frequency depending on the service provider). To access a Wi-Fi signal, a separate chip must be added, to communicate in the 2.4 gigahertz band.

Although some chip makers (such as Texas Instruments) have built and deployed "triband" and "quadband" chips that can tune into three or four different bands, designing a truly universal chip that can access all frequencies has remained a challenge. But the incentive is there: a phone with a universal chip could access any service on the spectrum -- from local television and radio, to Wi-Fi and WiMax -- in addition to saving power and precious space within shrinking gadgets.

The wireless world doesn't need more "customized radios that you stuff into a handset," says Asad Abidi, professor of integrated circuits and systems at UCLA and lead researcher on the universal chip project. Instead, it needs "one versatile radio that is so general and so flexible that [it] can receive TV, Bluetooth connections, and wireless Internet."

This universal chip would provide flexibility similar to that of a car radio tuner, allowing most stations to be ignored, and zeroing in on just one frequency. The team's chip design, presented in February at the International Solid-State Circuits Conference in San Francisco, is work that moves toward making a "real tunable radio," says Bill Krenik, wireless advanced architectures manager at Texas Instruments. Abidi has designed a chip that is capable of accessing all the incoming radio signals, he says, over a spectrum from 800 megahertz to 5 gigahertz.

The UCLA team's work relies on a technological concept called "software-defined radio," or SDR. First proposed the early 1990s by Joe Mitola of Mitre Corporation, SDR is based on the concept of converting all incoming radio signals (which are electromagnetic waves and therefore analog) into digital 1s and 0s. This would enable a circuit's software to sort through different frequency bands, and pick out the one of interest. Using software bypasses the need to design and add a specific radio for each band.

 

Atheros Wireless N for Smartphones Actually Uses Less Power Than Slowass G

 

Wireless N in cellphones, it's happening next year: Atheros's AR6003 802.11n/Bluetooth chip for cellphones is tiny, has serious range and uses less power than their current wireless G chip, which is in the Zune HD. It'll hit phones around the second half of next year.

Atheros is not the first to claim an 802.11n chip for smartphones; Broadcom announced its BCM4329 months ago, and said it should begin shipping this quarter. Atheros will begin shipping its AR6003 in volume during the second quarter of 2010, giving Broadcom a substantial lead.

However, an Atheros spokesman claimed that its chip would offer dramatic power savings compared to its predecessor and the competition.

"It's true Broadcom has a nine-month lead with their mobile 11n solution for handsets," the Atheros spokesman said. "However, the Atheros AR6003 features the highest throughput performance, industry-leading energy-efficiency and is two to two-and-a-half times smaller than the Broadcom solution. The variable on the size depends on whether you include the Bluetooth and FM components as part of the solution; all three components comprise Broadcom's combo solution."

The AR6003 is Atheros' third-generation chip for mobile devices. Its second (the AR6002) which contained 802.11g functionality, was included in the Microsoft Zune HD, among others, according to Terry Ngo, senior manager of the consumer connectivity business for Atheros. The AR6002 was also included in roters from the top five networking vendors and notebooks and netbooks from seven of the top PC makers, Atheros said.

According to Ngo, the AR6003 consumes 20 percent less power than the 802.11g chip. The Zune HD's Wi-Fi chip also generated between 12 to 15 dBm, an estimate of the signal strength per miliwatt. The AR6003, by contrast, generates 19 dBm, enough to "provide four times the range extension of the Zune HD," Ngo said. "That's the same power as a wireless access point."

The AR6003 is a 1x1 802.11n chip, meaning it runs only a single channel across a single antenna. Most wall-powered access points run 2x2 arrays or higher, generating a stronger signal but requiring more power. The AR6003 achieves up to 48 Mbits/s in the 2.4-GHz band in 20 MHz mode, and 85 Mbits/s in 5 GHz in 40 MHz mode.

The AR6003 can connect simultaneously using both Bluetooth and Wi-Fi – intelligently prioritizing Wi-Fi traffic – and also includes support for the Atheros Direct Connect AP Mode, similar to the Wi-Fi Directad-hoc mode, originally known as Intel's My Wi-Fi. Using the Atheros Direct Connect AP Mode, users can tell the AR6003 to create a local Wi-Fi personal-area network that other wireless devices can connect to and use as a bridge, at the same time that the chip is actively communicating with another gateway.

Although Ngo declined to give an exact price for the chip, the total solution should cost OEMs about $10, although that price naturally varies with volume; the addition of Atheros as a second supplier will also help drive down prices. Atheros claims the AR6003's size is only 5 mm by 5 mm, 50 percent smaller than the AR6002.

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