Seamless Collaboration brings some new usage models to Intel^® Centrino^® mobile technology 2006 platforms with the focus on enhancements for integrated communication devices. These new usage models allow the notebook to become an effective communication device for voice anytime/anywhere. There are several hardware/firmware, software/drivers, and optimization components that support the Seamless Collaboration architecture.

There are three key usage scenarios that will be enabled by Seamless Collaboration: "Office on the Go," "Multi-party VoIP conferencing," and "Integrated communication experience."

Office on the Go

This enables users to use their Intel Centrino mobile technology notebooks as a central communication device for voice anytime/anywhere. The user can make and receive voice calls anywhere as long as he/she has IP network connectivity to his/her enterprise network, as if he/she were physically present at the office. Many users will be connecting to their respective IP networks via WLAN and will use wireless headsets/handsets using Bluetooth*. This usage model also allows the user's calls to be automatically routed to the user's current location. For example, the user could have incoming calls to both his/her desk and cell phone be automatically forwarded to his/her notebook softphone, whenever connected to the enterprise network. The user would be able to configure which phones and calls are automatically forwarded to his/her current location. This way the user can effectively create a virtual office experience.

Figure 1: Office-on-the-Go scenarios
 

Multi-Party VoIP Conferencing

This feature enables users to use VoIP softphones for multi-party audio conferencing (including adhoc and bridge-based conferences) with optimized narrow-band and wide-band audio codecs and Intel Microphone Array open audio technology. This usage scenario allows a user to conference in more than two parties using the softphone application on the notebook, thus saving on expensive conference bridges. Dual core and other platform ingredient technologies enable hosting N multi-party conferencing sessions on Intel Centrino mobile technology, where N is greater than 8.

Integrated Communication Experience

One instance of this usage scenario provides users the facility to receive their voice messages as e-mail in their Outlook? inbox. This allows users to access their voice mail stored as e-mail in their inboxes and to listen to them in any order. Users can also choose to reply to the voice mail via a text message. Other instances of this usage scenario include integrated optimized softphones with productivity and e-business enterprise applications (Click-to-Dial scenarios). For example, if an employee in the company's Enterprise Resource Planning (ERP) system has a question or inquiry about a transaction, he/she can click to dial customer support and instantly talk with a support representative.

Key VoIP Client Components

Softphone Application

A softphone is a software VoIP application that provides a phone-like user interface to a notebook user complete with a dialing pad on the screen that can be clicked with a mouse. The softphone application may interface with external peripheral devices such as Bluetooth or a USB microphone and/or headset. Some softphone applications may also allow a user to configure VoIP parameters such as voice codec, call characteristics, or data rate.

Most softphone applications require a call manager on the network that authenticates softphone users, maps phone extensions to IP addresses, and routes VoIP call signaling messages between softphone users. A call manager can run on a server for PC-to-PC calling. Alternatively, a call manager can be integrated with a hybrid PBX, in which case it can also provide a connection to the enterprise and external PSTNs.

Audio Peripherals

A softphone application uses notebook audio peripherals such as codecs, built-in speakers, and microphones to convert user speech into VoIP packets and vice versa. Alternatively, USB or Bluetooth peripherals, such as handsets, headsets, speakers, and microphones, can also be used as audio peripherals.

Audio Codecs

A software audio coder-decoder (codec) is needed to sample and encode audio from a microphone to bits that can be sent in a VoIP packet and to decode bits from incoming VoIP packets to audio signals that can be played through the speakers or headphones. A variety of codecs is available for different conditions such as available bandwidth, audio quality, protection from lost packets, etc. Most audio codecs developed in the last few years were either designed to provide quality comparable to PSTNs (e.g., G.711 [8]) or to allow the use of VoIP with low-bandwidth networks such as dial-up (e.g., G.729 [8]). These codecs typically sample human voice signals at 8 kHz to allow representation of audio frequencies up to 4 kHz. Codecs with sampling rates up to 8 kHz are known as narrowband codecs. More recently, wideband codecs have been developed with sampling rates as high as 16 kHz, which typically result in better perceived audio quality than is possible with narrowband codecs, because audio frequencies up to 7-8 kHz can be adequately represented. The use of such codecs is however limited to PC-to-PC VoIP calls, because a PSTN typically cannot transport or reproduce audio frequencies higher than 4 kHz.

Each codec can work with one or more frame rates, e.g., 20 ms, 30 ms, etc. A frame rate represents the time interval for which converted audio bits are encapsulated in an RTP packet to be sent to the other VoIP endpoint. Depending on the encoding algorithm, a codec produces either a fixed size or a variable size (in bits) audio sample. The data packet transmitted over a LAN or WLAN also consists of a User Datagram Protocol (UDP), an Internet Protocol (IP), a Logical Link Control (LLC), and Media Access Control (MAC) headers.