The TVM4 is a reliable and flexible peoplemeter, incorporating new technology to provide clients with a
peoplemeter capable of meeting the technological needs of today's broadcasting environment.
The primary guidelines followed by the design team were reliability, an unobtrusive profile and easy installation
and maintenance. The TVM4 incorporates innovation in unobtrusive data acquisition, requiring ‘plug-in’ installation
for all TV sets, VCRs and all receivers and decoders equipped with a serial port.
The TVM4 is capable of identifying all channels available on analogue and digital platforms, and has
the ability to recognise video recording and time-shifted viewing. It also measures all guest viewing, including basic demographic information.
Identifying Digital Broadcasts
Digital Broadcasts with Service Information
The TVM4 is capable of receiving any type of code or information passed from the broadcast signal to
the meter via the digital receiver. When these codes are present, the channel is identified by the unique broadcaster code.
Digital Broadcasts without Service Information
When Service Information is not provided, TVM4 uses the proprietary Content Tracking System (CTS) for channel identification.
CTS is based upon the comparison of digital signatures extracted from the audio signals, using specific algorithms
developed internally. The audio signal from the unknown content is converted in a continuous signature stream and then
compared to a set of reference streams, which identifies the original content and the channel viewed.
Time-Shifted Viewing
Although Content Tracking System (CTS) is used for the identification of digital broadcasters who do not provide any
form of service or banner information; it was developed primarily for the identification of time-shifted
viewing. When CTS is used during the playback of recorded material to identify the content and the channel the statement is recorded within the TVM4.
The TVM4 also has the ability to monitor the remote control’s infrared signals, providing another source of channel
identification for back-up purposes. CTS also allows the meter to register Teletext page viewing.
Each TV set in the home is monitored by its own meter (the Base Unit). Each meter communicates with
a central Transmission Unit, installed near the telephone, via a radio frequency link, thus eliminating the need for
ny additional cabling within the home. The production centre, via the telephone line, retrieves the data from the Transmission Unit daily.
The TVM4 can be equipped with a GSM modem which allows the production centre to retrieve data at any time of the day.
Using the SMS facility of the GSM modem, it is also possible to collect data in 'real-time'.
Identifying Analogue Broadcasts
Sync Comparison
The primary method for identifying channels is accomplished by a comparison between the sync of the channel viewed and the sync of
all channels available, through the broadcast source (antenna, cable connection, etc.). The meter is connected to the same source of
the broadcast signal and by means of an inductive pick-up to the outer casing of the TV set.
Video Signal Comparison
In the event that the TV set is equipped with a SCART or A/V plug, the meter identifies the channel viewed by
comparing the video signal of the channel with those of all channels available.
Audio Comparison
In the event that it is not possible to distinguish the sync or the video signal for comparison, the channel is identified
by means of an external audio comparison attached to the external casing of the TV set.
In all three instances, the meter is connected to the TV set externally, rendering the 'installation' completely unobtrusive.
