Low Roundtrip

Low Roundtrip

Small waves

Ronja uses light waves which are very small and give Ronja property which is unique compared to most other wireless systems. As the waves are only 1/1500 of millimeter in size, they are very easy to separate and shield using a passive obstacle between the transmitter and receiver.

Self-jamming in radio systems

Radio systems work with big waves (like 12cm in case of 2.45GHz) which bend easily around any obstacle which is part of the transmitter and receiver. During transmission, part of the relatively very strong transmitted power always gets into the receiver and jams the reception of the delicate signal coming from the other side. Because of this problem, most existing radio system are half duplex.

Half duplex and full duplex

The difference between half duplex and full duplex is like between a stacked freeway interchange and a level crossing with traffic lights. On the freeway interchange the cars don't care what is happening in the other direction and just smoothly flow. On a level interchange a car has to wait until the other direction clears the crossing. This introduces extra delay, slows down the traffic and causes the delay not to be constant, but dependent at which time the car (or a packet) comes.

Ronja roundtrip performance

Because of it's full duplex nature, Ronja system has very low roundtrip time which doesn't depend on load. For example we tested a system of two Ronja datalinks connected in series. They were connected using three Linux routers (two at the ends plus one in the middle). The resulting roundtrip was still under 1ms.

Uses of low roundtrip

Low roundtrip can be used especially by gamers, who strive for the lowest roundtrip possible. Low roundtrip is also beneficial for multimedia and keeps fast response in remote access like SSH, VNC or X Window System. Low roundtrip also helps to keep fast response when loading WWW pages.