August 27-31, 2007, Kyoto, Japan | Sachin Katti, Shyamnath Gollakota, and Dina Katabi
Analog Network Coding (ANC) is a technique that leverages wireless interference to increase network capacity. Unlike traditional wireless networks that avoid interference, ANC encourages strategically chosen senders to interfere, allowing routers to forward the resulting signals. The destination then cancels the interference to recover the desired signal. This approach doubles the capacity of the canonical 2-way relay network, and is both theoretically and practically effective. The paper presents a novel algorithm for ANC that does not require synchronization, enabling it to exploit the lack of synchronization between interfering signals. By inserting random delays before transmission, ANC ensures that interference-free bits are present at the beginning and end of the signal, allowing receivers to estimate wireless channels and decode packets. The algorithm is implemented using software radios, demonstrating significant throughput improvements over traditional wireless routing and digital network coding. ANC is shown to reduce the number of time slots needed for packet transmission, doubling throughput in the Alice-Bob topology. The paper also addresses practical challenges, such as channel and hardware distortions, and provides a trigger protocol to encourage simultaneous transmissions from the right senders. Theoretical analysis shows that ANC can asymptotically double throughput as the signal-to-noise ratio (SNR) increases. The results demonstrate that ANC is a practical and effective method for increasing wireless network capacity.Analog Network Coding (ANC) is a technique that leverages wireless interference to increase network capacity. Unlike traditional wireless networks that avoid interference, ANC encourages strategically chosen senders to interfere, allowing routers to forward the resulting signals. The destination then cancels the interference to recover the desired signal. This approach doubles the capacity of the canonical 2-way relay network, and is both theoretically and practically effective. The paper presents a novel algorithm for ANC that does not require synchronization, enabling it to exploit the lack of synchronization between interfering signals. By inserting random delays before transmission, ANC ensures that interference-free bits are present at the beginning and end of the signal, allowing receivers to estimate wireless channels and decode packets. The algorithm is implemented using software radios, demonstrating significant throughput improvements over traditional wireless routing and digital network coding. ANC is shown to reduce the number of time slots needed for packet transmission, doubling throughput in the Alice-Bob topology. The paper also addresses practical challenges, such as channel and hardware distortions, and provides a trigger protocol to encourage simultaneous transmissions from the right senders. Theoretical analysis shows that ANC can asymptotically double throughput as the signal-to-noise ratio (SNR) increases. The results demonstrate that ANC is a practical and effective method for increasing wireless network capacity.