Stanford University researchers have developed an innovative technology for enabling the simultaneous transmission and reception of wireless signals over a single Wi-Fi channel. The goal is to help wireless service operators double the speed of their existing networks.
Until now, wireless communication over a single channel has been limited to sequential transmit and receive operations. Last September, however, Stanford researchers Jung Il Choi, Kannan Srinivasan, Mayank Jain, Philip Levis, and Sachin Katti reported on their development of an innovative technique called antenna cancellation that filters out self-interference on a single communications channel to such an extent that full duplex communications can take place.
When a radio is transmitting, its signal is millions or even “billions of times stronger than anything else it might hear — it’s [like] trying to hear a whisper while you yourself are shouting,” said Stanford Assistant Professor Philip Levis. However, a radio receiver can now be built that can filter out the substantial noise generated by its associated transmitter, “so you don’t hear your own shout and you can hear someone else’s whisper,” Levis explained.
Improving Wi-Fi Performance
Due to the more challenging real-time requirements of enabling voice communications to run over cellular networks, the researchers are currently focused on applying their breakthrough to Wi-Fi networks. However, the new antenna-cancellation technique is not Wi-Fi specific and so may eventually also be deployed by cellular networks and other wireless communication operators.
In the Wi-Fi space, Levis envisions some simple and basic applications for the new technology that could improve Wi-Fi performance and be backward compatible with existing 802.11 standards. To take advantage of the technology’s range of capabilities, however, the creation of a new standard or an extension of an existing standard may be required.
On the other hand, there is nothing to stop vendors from quickly moving to embrace…