FaceTime 101
When Apple introduced the iPhone 4 in June of 2010, the
company was most proud to announce its impressive video calling application,
FaceTime. Although FaceTime is “far from the first mobile video calling
solution available”, the public was captivated with this technology. Apple,
Inc. is recognized as being highly innovative, “taking existing technologies
and making them smoother, more usable, and better understood”. [1]
Apple, in fact, promises to make FaceTime the standard for the industry in order to address the problem of interoperability. [2] Given this bold promise and Apple’s history of innovation, FaceTime is likely to turn video calling into a conventional means of communication. Thus, FaceTime stands out from its competition and is the one to watch out for.
Apple, in fact, promises to make FaceTime the standard for the industry in order to address the problem of interoperability. [2] Given this bold promise and Apple’s history of innovation, FaceTime is likely to turn video calling into a conventional means of communication. Thus, FaceTime stands out from its competition and is the one to watch out for.
Nuts and Bolts: How FaceTime Works
Steve Jobs explaining the technology behind FaceTime.
Photo Courtesy Apple Insider.
A number of technologies are involved in making FaceTime work:
This "core technology stack" is unique to FaceTime. [3] As discussed earlier, a problem of interoperability exists in the industry, which is explained by the fact that no single set of standards exists. Unlike its competitors, FaceTime is operating under open standards that any application can follow. This places FaceTime in a strong position to resolve the issue and emerge as the leader in the industry.
These technologies follow a sequence of events to make a FaceTime video call work. First, the sending device uses STUN to learn its IP address, and TURN to establish an auxiliary data path between the sending and receiving device. Next, SIP sends an invitation to the receiver, which contains the network information found by STUN and TURN. When the invitation is accepted, ICE determines which pairs of IP addresses can be used flow data between the devices. Once this is completed, the devices use RTP and SRTP to interact with each other. This complex sequence of events can be explained quite simply: Someone makes a FaceTime video call, and within a few seconds, someones answers. [4]
- H.264 video codec; ACC audio codec
- Session Initiation Protocol (SIP) - the Internet Engineering Task Force's (IETF) signaling protocol for VoIP
- Session Traversal Utilities for NAT (STUN); Traversal Using Relay NAT (TURN) - IETF technologies for dealing with network address translation
- Interactive Connectivity Establishment (ICE) - the IETF standard for traversing firewalls
- Real Time Protocol (RTP); Secure RTP (SRTP) - IETF standards for real time media streams and encrypted data streams
This "core technology stack" is unique to FaceTime. [3] As discussed earlier, a problem of interoperability exists in the industry, which is explained by the fact that no single set of standards exists. Unlike its competitors, FaceTime is operating under open standards that any application can follow. This places FaceTime in a strong position to resolve the issue and emerge as the leader in the industry.
These technologies follow a sequence of events to make a FaceTime video call work. First, the sending device uses STUN to learn its IP address, and TURN to establish an auxiliary data path between the sending and receiving device. Next, SIP sends an invitation to the receiver, which contains the network information found by STUN and TURN. When the invitation is accepted, ICE determines which pairs of IP addresses can be used flow data between the devices. Once this is completed, the devices use RTP and SRTP to interact with each other. This complex sequence of events can be explained quite simply: Someone makes a FaceTime video call, and within a few seconds, someones answers. [4]
Features and Limitations
Several features exist that are quite unique to FaceTime. First of all, it is available free of charge. Another feature that makes it appealing to consumers is its simplicity. There is no need to create an account or some sort of screen name; rather, FaceTime can be used "right out of the box". FaceTime also makes video calling quite "seamless". A user simply taps the FaceTime button to engage in a video chat session. Another popular feature is its flexibility. FaceTime can work in both portrait and landscape modes. The application can utilize either the front or the back camera to share video streams. [5]
One limitation of FaceTime is its interoperability. When it was debuted in 2010, FaceTime could only be used to make video calls from iPhone 4 to iPhone 4. This has been expanded to include most Apple products, namely the extremely popular iPad 2, iPod Touch, and Mac. [6] Nevertheless, FaceTime is still quite limited for consumers who do not own any of these products.
Another limitation is that FaceTime only works on WiFi, which is due to a number of reasons. First, the current 3G networks are "less reliable [and have] limited bandwidth". Second, prices over 3G networks are not feasible to make FaceTime (or any similar application) "fly in mass adoption". However, because most people have access to WiFi at home or work, this limitation is "less of an issue". [3]
One limitation of FaceTime is its interoperability. When it was debuted in 2010, FaceTime could only be used to make video calls from iPhone 4 to iPhone 4. This has been expanded to include most Apple products, namely the extremely popular iPad 2, iPod Touch, and Mac. [6] Nevertheless, FaceTime is still quite limited for consumers who do not own any of these products.
Another limitation is that FaceTime only works on WiFi, which is due to a number of reasons. First, the current 3G networks are "less reliable [and have] limited bandwidth". Second, prices over 3G networks are not feasible to make FaceTime (or any similar application) "fly in mass adoption". However, because most people have access to WiFi at home or work, this limitation is "less of an issue". [3]
Sources:
[1] Segan, Sascha. (2010). “iPHone 4’s FaceTime Video Calling Isn’t a First.” PC Magazine. Retrieved from http://www.pcmag.com/article2/0,2817,2364801,00.asp
[2] Aamoth, Doug. (2010). “Why Would Apple Open Up Its ‘FaceTime’ Video Standard?” Time Magazine. Retrieved from
http://techland.time.com/2010/06/07/why-would-apple-open-up-its-facetime-video-standard/
[3] Dilger, Daniel Eran. (2020). “Inside iPhone 4: FaceTime video calling.” Apple Insider. Retrieved from
http://www.appleinsider.com/articles/10/06/08/inside_iphone_4_facetime_video_calling.html
[4] Strowes, Steven D. (2010). iPhone 4, FaceTime, and open standards. [Web log article]. Retrieved from
http://youshottheinvisibleswordsman.co.uk/2010/06/25/iphone4-facetime-and-open-standards/
[5] iPhone 4.(2011). Apple, Inc. Retrieved from http://www.apple.com/iphone/features/facetime.html
[6] FaceTime for Mac. (2011). Apple, Inc. Retrieved from http://www.apple.com/mac/facetime/
[1] Segan, Sascha. (2010). “iPHone 4’s FaceTime Video Calling Isn’t a First.” PC Magazine. Retrieved from http://www.pcmag.com/article2/0,2817,2364801,00.asp
[2] Aamoth, Doug. (2010). “Why Would Apple Open Up Its ‘FaceTime’ Video Standard?” Time Magazine. Retrieved from
http://techland.time.com/2010/06/07/why-would-apple-open-up-its-facetime-video-standard/
[3] Dilger, Daniel Eran. (2020). “Inside iPhone 4: FaceTime video calling.” Apple Insider. Retrieved from
http://www.appleinsider.com/articles/10/06/08/inside_iphone_4_facetime_video_calling.html
[4] Strowes, Steven D. (2010). iPhone 4, FaceTime, and open standards. [Web log article]. Retrieved from
http://youshottheinvisibleswordsman.co.uk/2010/06/25/iphone4-facetime-and-open-standards/
[5] iPhone 4.(2011). Apple, Inc. Retrieved from http://www.apple.com/iphone/features/facetime.html
[6] FaceTime for Mac. (2011). Apple, Inc. Retrieved from http://www.apple.com/mac/facetime/
