Student makes cableless cable

Matthew DePetro ’05 earned top honors for his senior design project, “Wireless Cable Television.” The first-prize entry “untethers” standard cable TV and even eliminates the need for a wall outlet.

“All of the rooms that I have lived in at Harvard have such crummy standard TV reception that something as simple as watching the 11 o’clock news is an unfulfilling experience,” says DePetro. “Unfortunately, cable television service suffers from the inherent shackles of a cable for signal distribution. In a typical dorm residence that means television sets must be located near a cable outlet in the wall.”

Moreover, setting up cable for multiple sets in separate rooms requires adding extra wiring infrastructure within a building itself – no easy feat in older structures. This costly add-on hints at why residents in large living units, such as college dorms, typically huddle around a central set rather than watch shows from the comfort of their own pads.

The solution to gaining a greater variety of programming and better reception, was, bad pun intended, in the air. With the help of his adviser, Assistant Professor of Electrical Engineering Donhee Ham, DePetro exploited the same wi-fi technology that allows laptop users to instantly go online indoors or out. He transmitted the cable TV signal from a single wall point to free-roaming locations within a residence.

“Wirelessly broadcasting the cable television spectrum in its entirety, however, is not feasible because there’s not enough free bandwidth in the air,” explains DePetro. He overcame that obstacle by tuning an individual channel at a base transmitter and then broadcasting only that channel to a special receiver device.

To change a channel a separate signal is sent from the receiver module to the base transmitter to control the tuner. The result: the entire cable spectrum is available for viewing, wirelessly, one channel at a time. With broadcasts no longer wall- or wire-bound, individual rooms could one day be made cable-ready cheaply and quickly.

“I would actually love to commercialize this device, but it would require a partnership with an industry presence and further development and advancement to polish it off and prepare it for the consumer market,” says DePetro.