Motorola Inc. is introducing a family of voice-enabled cable modems that will use Session Initiation Protocol (SIP), a critical element of CableLabs' new PacketCable 2.0 standard, to support advanced multimedia services for cable VOIP users.

Motorola said the new SIP-equipped voice modems, known as the SBV5100 series, will let cable operators support such much-anticipated applications as dual-mode mobile phones that can switch between cellular and Wi-Fi networks. The integration of SIP into the voice modems will also enable cable operators to offer other new new services, such as instant messaging, multimedia streaming, interactive video, and more goodies.

Plus, the giant tech vendor said the new voice modems will provide cable operators with an easier "migration path" to the industry's still-evolving PacketCable 2.0 standard. The draft spec, released earlier this year by CableLabs, is designed to support wireless telephony and a wide range of other advanced, voice-related services.

Motorola said the SBV5100 series will support primary, multi-function VoIP service on up to two phone lines through links to RJ-11 connectors. The company aims to make the new product available by the end of the year.