Tecnologie e Società


Public WiFi Network 2 Public Cable Network
Drazen Pantic


Experimental Broadcast: Public WiFi Network 2 Public Cable Network

What is the Experiment About?

The goal of the experiment is to establish procedure and criteria for broadcasting to the cable or satellite TV network from remote locations, using laptop, camera and any type of available broad-band Internet connections - preferably WiFi.

The motivation for such an exercise is the attempt to break away from classical TV production in a studio environment and enable immediate and on-the-fly transmission from remote locations to the TV network, ultimately leading toward creative production of program from within a P2P network.

How Was It Done?

Bryant Park in New York is one of the largest public WiFi access points, with enough bandwidth to carry Internet streaming at sufficiently high quality, acceptable for TV transmission. Prior to the experiment, the following quality threshold has been established:
* video quality: 320x240 pixels in size, with 8 frames per second, encoded by an open MPEG4 video codec (Xvid);
* audio quality: 128 kbps AAC or MP3 compression codec.

Hardware and software were deliberately composed in order to be within the reach of a mid-skilled Internet user: a standard IBook with OS X operating system and (publicly available) QuickTime Broadcaster as well as a digital camera. Alternative, and more preferable solution would be a fully Open Source solution: a PC laptop with Linux operating system and MPEG4IP software bundle.

The Internet broadcast was then unicast via WiFi network (installed in the Bryant park by to the computer at MNN ( and finally transformed to a video signal by a scan converter. The signal was then channeled into a video mixer and played in an experimental setting as a regular broadcast stream.

What Were the Results of the Experiment?

The most important result is that the concept is valid: the current consumer-level technology, coupled with broad-band Internet, offers viable framework for distributed TV production and distribution via the Internet.

Connectivity and bandwidth found in Bryant Park was sufficient enough for the Internet broadcast to the MNN headquarters. While we stayed in the range of 500-800 kbps range, we did not fined any significant bandwidth congestion.

Video quality and the smoothness of the video has varied, according to what compression codec or image quality we have used, but as general rule we concluded that the image quality is very good, but we would need additional resources (more efficient software or more powerful CPU) to archive a goal of of constant 8 frames per second rate.

It would be interesting to test x86/Linux/MPEG4IP combination in the same setup. Some preliminary tests from PC desktop show slightly better results.

What is the Road-Map for the Future?

* assemble a PC version of the remote broadcaster, based fully on Open Source software and conduct equivalent tests;
* compile easy plug-and-play software setup, convenient for standard mid-skilled users
* make a bootable Linux CD, with all the software needed, and as many WiFi, audio and video device drivers included, enabling immediate establishing of broadcast services upon boot.

Who and When has done the experiment?

Experiment was conducted on a particularly cold day in January 2003, by (in alphabetical order)

Kenyatta Cheese (MNN)
Martin Lucas (Hunter College)
Drazen Pantic (Location One)

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