IBBT Tr@ins project Bart Jooris Fast WiFi Handover IBBT Tr@ins project Bart Jooris Goodafternoon In the next 5 minutes I will present a fast WiFi handover implementation which was developed within the framework of the IBBT trains project

Standard WiFi mobility support WiFi handovers imply “long” delays Suppose that we want to support wideband internet on a train then we will need a link in the order of 1Gbs To let the passengers enjoy the wideband experience they are familiar with A potential wireless technology to achieve this goal is WiFi if we want to cover a railway with WiFi we will need to install sufficient WiFi APs. With typical train speeds a train will pass a WiFi AP every 7 seconds Unfortunately, standard WiFi was not really developed to handle these frequent handovers. The weakness of WiFi is shown in this animation We have three AP working on their own channel Every channel is represented by a color. The train is represented by a user with his terminal. The terminal is red so is connected to the red AP When its moving and it leaves the reds zone it gets disconnected With standard WiFi the terminal must search for a new channel which can take up to 1 second. In this second the terminal is disconnected. the overlap zone is not utilized ? ?

How can we improve (fasten up) the handover We will utilize the overlap zone to solve the problem Here we see a more detailed topology with a piece of the wired network and the central switch The solution comes by installing an extra wireless interface on the APs which can listen to the channel of its neighbor

IBBT Tr@ins WiFi mobility support When we apply this solution to our scenario you will see that WiFi now can support seamless handovers.

Demo In the field the antenna’s will be a few hundred meters apart, To emulate this in this room we use our cosmotec units which are cages of faraday To accomplish this.