Push Technology

[Ben Kim]

Hello all,

We are re-developing a software product that requires push technology
(wireless and hardwired). Microsoft used to support this technology in IE
but dropped it for whatever reason.

The system is a dispatch application. When a call comes in, the operator
will assign a vehicle(s) to the call and the system should push a message
out to each vehicle selected.

The connected vehicles should not have to have a persistent connection back
to the host since there are dead areas where they travel (of course they
will have a backup method - good ol' radio). The vehicle machine will
automatically post an acknowledgement back to the host system.

Host System (Server and Client)
Vehicle 1 (Server and Client)
Vehicle 2 (Server and Client)

We are considering using TCP again or maybe a protocol of our design riding
on UDP. We have considered using a polling method but have rejected the
idea due to "chatter" and several hundred users could be online at any one
time.

Has anyone else ventured down this path and have any input or know of any
third party add-on components specifically designed for this purpose?

Using VS2005 - VB.NET (Winforms and Webforms)

Thanks!

Ben Kim
Emergitech

 

[Rob R. Ainscough]

If anything within the message/data stream is deemed sensitive, I would
avoid TCP unless you encrypt which will tend to degrade complete packets or
increase the vehicles "out of service" range.

Polling would be ok with several hundred concurrent users (pretty easy to
setup a test situation to confirm this and you can determine your capacity
maximum).

I would avoid 3rd party for a system like this -- getting VS 2005 to work
well fully managed is hard enough with it's current level of bugs, tossing
in 3rd party elements is really pushing it and reducing your flexibility.

 

[Nick Malik [Microsoft]]

Hi Ben Kim,

Hello all,

We are re-developing a software product that requires push technology
(wireless and hardwired). Microsoft used to support this technology in IE
but dropped it for whatever reason.

The system is a dispatch application. When a call comes in, the operator
will assign a vehicle(s) to the call and the system should push a message
out to each vehicle selected.

The connected vehicles should not have to have a persistent connection
back to the host since there are dead areas where they travel (of course
they will have a backup method - good ol' radio). The vehicle machine
will automatically post an acknowledgement back to the host system.

Host System (Server and Client)
Vehicle 1 (Server and Client)
Vehicle 2 (Server and Client)

when you say that the vehicle has a server, are you also saying that it has
a fixed IP address? If so, you are OK. If not, UDP isn't going to work
any better than TCP.

Assuming you can't keep a single address: What you could do is that when a
vehicle is online and reachable, it acquires an IP address and transmits
information to the central machine: vehicle id and IP address. Then it sits
and waits. When the central system gets a message to pass on, you can
literally call a web service on the vehicle to pass the data.

We are considering using TCP again or maybe a protocol of our design
riding on UDP. We have considered using a polling method but have
rejected the idea due to "chatter" and several hundred users could be
online at any one time.

If the time between sending a message and receiving it can exceed 30
seconds, then polling is viable even for several thousand vehicles.
Problems arise if you are paying by the packet.

Has anyone else ventured down this path and have any input or know of any
third party add-on components specifically designed for this purpose?

I've seen apps like this that leverage the SMS network (cell phone text
message). There are third party controls in this space. You may want to
look into that.

Good luck,

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--

 

[Ben Kim]

Nick,

Thank you for the ideas. In most cases yes it will be a fixed IP but not
all which your suggestion of registering the vehicle's ID and IP are
wonderful.

Thank you to for the SMS idea. I could use SMS to inform the vehicle that a
new message has arrived in MSMQ or my own packet and it could dial up the
server and download it...

All wonderful ideas! Will MS ever bring back the push technology???

Ben

 

[Nick Malik [Microsoft]]

Hi Ben

Will MS ever bring back the push technology???

Don't know.. Can't say... I don't work with the product team... all that
stuff.

I wish you the best of luck.

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--