Wireless roaming(helicopter project)..

Hey everyone.
Im a part of a project where we are designing a robust communication
system for a model-helicopter with a combination of Wlan and radio
modem. The idea is to use Wlan when it is within range and switch to
radio modem otherwise. Both connections use tcp/ip(The radio modem via SLIP)

We have worked out how to write an application which can do this in an
applikation. However, the best solution would be to construct a layer
between the tcp-layer and the applikation-layer to manage the shifting
connection-availability. The theory is that in this way it would be
possible to connect to the helicopter via ssh or ftp and maintain those
connections even when the connection shifts from Wlan to radio-modem and
vice versa..

My question is this.. Is this even possible to write an application that
can facilitate continous connection from the ssh/ftp-client though? That
is without having to rewrite the tcp-protocol or something :-)

If anyone has some pointers regarding what is needed to do this i would
be very much appriciated.. Anyone know of any other similar projects?

Kind Regards
Martin Holm Pedersen
Group 736
Aalborg
Denmark

Martin Holm Pedersen wrote:
> Hey everyone.
> Im a part of a project where we are designing a robust communication
> system for a model-helicopter with a combination of Wlan and radio
> modem. The idea is to use Wlan when it is within range and switch to
> radio modem otherwise. Both connections use tcp/ip(The radio modem via
> SLIP)
>
> We have worked out how to write an application which can do this in an
> applikation. However, the best solution would be to construct a layer
> between the tcp-layer and the applikation-layer to manage the shifting
> connection-availability. The theory is that in this way it would be
> possible to connect to the helicopter via ssh or ftp and maintain those
> connections even when the connection shifts from Wlan to radio-modem and
> vice versa..
>
> My question is this.. Is this even possible to write an application that
> can facilitate continous connection from the ssh/ftp-client though? That
> is without having to rewrite the tcp-protocol or something :-)
>
> If anyone has some pointers regarding what is needed to do this i would
> be very much appriciated.. Anyone know of any other similar projects?
>
> Kind Regards
> Martin Holm Pedersen
> Group 736
> Aalborg
> Denmark
Do you familiar with router? I feel that you just want a fallback
operation for network link layer when a primary path is failed. You can
easily find information for redundancy of network connection over
internet. Good luck

root wrote:
> Martin Holm Pedersen wrote:
>
>>Hey everyone.
>>Im a part of a project where we are designing a robust communication
>>system for a model-helicopter with a combination of Wlan and radio
>>modem. The idea is to use Wlan when it is within range and switch to
>>radio modem otherwise. Both connections use tcp/ip(The radio modem via
>>SLIP)
>>
>>We have worked out how to write an application which can do this in an
>>applikation. However, the best solution would be to construct a layer
>>between the tcp-layer and the applikation-layer to manage the shifting
>>connection-availability. The theory is that in this way it would be
>>possible to connect to the helicopter via ssh or ftp and maintain those
>>connections even when the connection shifts from Wlan to radio-modem and
>>vice versa..
>>
>>My question is this.. Is this even possible to write an application that
>>can facilitate continous connection from the ssh/ftp-client though? That
>>is without having to rewrite the tcp-protocol or something :-)
>>
>>If anyone has some pointers regarding what is needed to do this i would
>>be very much appriciated.. Anyone know of any other similar projects?
>>
>>Kind Regards
>>Martin Holm Pedersen
>>Group 736
>>Aalborg
>>Denmark
>
> Do you familiar with router? I feel that you just want a fallback
> operation for network link layer when a primary path is failed. You can
> easily find information for redundancy of network connection over
> internet. Good luck

Thank you for your reply.
Yes, i am familiar with routing. Are you saying that, if i just have two
routes in my routing table, the other one will kick in if one failes
without loosing my ssh connection?
Do you have any good links? I feel like I'we searched the entire
net..twice:-)

Regards
Martin Holm Pedersen