Chips Ahoy for Wi-Fi Phones

By Vikki Lipset

December 11, 2003

Chipmaker Atmel sets its sights on wireless VoIP.

A Wi-Fi semiconductor company has introduced a design that will make it easier for handset makers to create wireless voice over IP (VoIP) phones.

Atmel's AT76C901 allows original equipment manufacturers (OEM) and original design manufacturers (ODM) to implement an entire phone design with very few active components, said Richard Bisset, a product marketing director at the San Jose, Calif.-based company.

The system-on-a-chip (SoC) includes two 32-bit ARM-based RISC processors that run VoIP stacks and the 802.11b media access control (MAC) layer ; a DSP for voice compression and decompression; and an integrated voice codec. "The only main actives you would have outside of this are flash, SDRAM, battery, keypad, LCD and the radio subsystem," Bisset said.

Several manufacturers, including Cisco , have developed handsets using the chip. The Cisco phone, which the networking giant announced in April, is shipping now, and Bisset said some Asian OEMs are about to release their devices to production.

Voice is considered to be one of the most promising applications for wireless LANs, but so far voice over WLAN (VoWLAN) has only been embraced by vertical sectors such as health care and education. Two areas of concern that have thus far prevented more widespread adoption are quality of service (QoS) and battery life.

The AT76C901 supports enhanced distributed coordinated function (e-DCF), one of the proposed QoS specifications within the upcoming 802.11e standard. Bisset said that the chip can be upgraded through firmware to comply with the final standard when it is ratified.

As for battery life, he said the Atmel VoIP chip offers talk times of more than four hours. He wouldn't get specific about standby times, but said they were comparable to some of today's cell phones. He noted that the type and size of the battery that the OEM uses also impacts battery life.

Bisset hinted that Atmel will soon address another perceived barrier to VoWLAN deployment -- seamless roaming. He said the company is "on the verge of announcing a new wireless roaming protocol" for low-latency handoffs.

While the AT76C901 is designed for wireless VoIP handsets such as those offered by Cisco and SpectraLink, Bisset noted that some manufacturers are also looking at the chip for use in a dual-mode cellular and Wi-Fi phone. Such phones would allow users to roam from cellular wide area networks (WAN) to 802.11 networks.

The first dual-mode phones are expected to ship next year. Nokia, the world's largest handset maker, is rumored to have a dual-mode phone in the works that could hit the market in the first quarter of 2004. Rival Motorola plans to offer one next year using a chip from Texas Instruments. In addition, Japanese wireless operator NTT DoCoMo said last week that it will introduce a dual-mode phone in the spring.

Bisset said there are no definitive plans yet for a cellular handset that incorporates the Atmel chip, but that such a phone is "probably about a year away."

In order to speed development time, Atmel is also offering a reference design kit (RDK) that includes the VoIP chip; a baseband, transceiver and power amplifier from RF Micro Devices; schematics; software; and gerber files. The AT76C901 is available in a 217-pin micro-BGA package for around $22 in 50,000-unit quantities. The pricing for the RDK was not available.



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