Atmel introduced its second generation VoIP chip, designed for 802.11a/g wireless phones. The device a Session Initiation Protocol (SIP) stack, uCLinux operating system software, and firmware enabling 802.11a/g (Wi-Fi) and voice compression and decompression all on a single chip.
The chip design consists of an ARM946 processor for VoIP call control, authentication and signaling functions, and two subsystems — an ARM7 and 802.11a/g Media Access Controller (MAC) that implements the 802.11a/g protocols, and a TEAK TeakDSPCore and integrated voice codec for voice processing functions. Additionally, hardware security accelerators offer on-the-fly encryption, decryption and authentication support for AES, DES/3DES and TKIP, supporting WPA and WPA2 — Personal and Enterprise.
Atmel said its chip supports Wi-Fi Multimedia (WMM) and WMM Power Save modes. WMM adds QoS capabilities to Wi-Fi networks. WMM Power Save is an improvement to the 802.11e amendment adding advanced power management functionality to WMM.
WMM Power Save is based on Unscheduled Automatic Power Save Delivery (U-APSD), which, like WMM, is based on Enhanced Distributed Channel Access (EDCA). U-APSD is suited for dynamic environments where Wi-Fi is generally deployed and allows clients supporting U-APSD to download all or some of the frames buffered by the access point during unscheduled service periods.
Atmel said that by supporting U-APSD and Scheduled APSD (S-APSD), solutions based on its chip have talk times of over six hours and stand-by times of over 220 hours on a 900 mA battery. This is achieved even when the access point it is connected to does not support WMM APSD.
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