Mobility and AvailabilityThe call control protocol of the V660 is based on the SIP v2 (Session Initiation Protocol version 2, RFC 3261) standard that interoperates with major SIP-based call servers, IP PBXs and other standard SIP-based client devices. Compliant with the IEEE 802.11b/g standard, the V660 works with any existing 802.11b or 802.11g wireless AP and gateway, and it can be used as a cordless handset in home or office environments as well. The small form factor makes the handset easy to carry and allows users to place VoIP phone calls in public IEEE 802.11-based environments. SIP-based Windows Mobile 5.0® Dual-Mode HandsetThe V660 is a SIP-based dual-mode handset running the Windows Mobile 5.0® operating system. The highly integrated next-generation handset utilizes the proven GSM/Wi-Fi dual-mode voice technology, and takes advantage of the versatile Windows operating system for mobile devices to further expand its usability and functionality. Multimedia SupportWith the built-in 1.3-megapixel camera, MP3/MP4 player and camcorder/recorder functionalities on a Windows Mobile® platform, users can access the Internet, listen to music, as well as take and review pictures all with one compact handset that also serves as a mobile phone. Pocket MSN and E-mail MessagingChat with friends over Pocket MSN, or access E-mail, contacts, calendar and tasks while you're away from the desk. Using a V660 along with the same Outlook application on your PC, you can access emails from any location where Internet connectivity is available. Language SupportsFor the first time ever, ZyXEL built three languages (English, Chinese and Spanish) right into V660 for users to read mails or Web pages, as well as to compose and edit messages in these languages effortlessly.