Roaming between WWAN and WiFi

Team,

A few of my customers are asking how to roam between WWAN and WiFi automatically (and back again).

Eg: Whilst the courier trucks are out on the road they are WWAN connected and when they hit the depot/office they auto roam to the WiFi. 
I know you can do it by enabling one radio/disabling the other.
But I guess they would need both radio's always on and for it to select one over the other.

I guess this then extends to Fixed Mobile Convergence for a VoiP app. 

Let's take one at a time. Data first. 

Can anyone shed any light on how to do this. Product is the MC75

Cheers
Harry
Anonymous (not verified)
First, we'll ignore the issue


First, we'll ignore the issue of battery drain when you have both the WLAN and WWAN radios active at the same time.

In theory, Microsoft's Connection Manager component is supposed to handle this scenario.  In practice, it doesn't do a very good job.  Keeping only one radio active at a time is good practice.  Otherwise, I've seen the connection manager get confused and then bad things happen.  Microsoft does keep improving this component and it's possible that it will some day live up to its promise.

One problem is the issue of when to switch between networks.  Just because you can see an access point doesn't mean that you should connect to it.  The signal may be too weak to allow any meaningful data throughput.  Same goes for a WWAN connection.

Also, you can only switch between networks before you open a TCP/IP connection.  Once a TCP/IP Connection is established, it must continue to use the current radio until the connection is closed or it times out.

We were asked by a large trucking company based in Portland, OR to handle this scenario (we were replacing equivalent functionality on an Intermec unit).  The solution was a component that would periodically look to see if a WLAN network was available (i.e. the Truck was in the yard) and then shutdown the WWAN radio so that the WLAN radio would be used.  Once the Truck left the yard, we would go back to polling the WLAN radio and leave the WWAN radio active.

We also had code in the WWAN component to allow for call screening.  The company wanted the drivers to be able to communicate with the dispatcher, but not use the WWAN radio to call friends and family.  The target platform for this code with the MC70/MC75 using WM 5.0 and then WM6.1 OS's.
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Dilshan Perera
Harry, We are working on a

Harry,

We are working on a similar solution to conserve power known as a power profiles using GPS. So essentially a depot could be Geo fenced and once a device is within this Geo fence you could switch to a particular power profile and when it is out could change into another profile.

With this method
Profile 0 could have the WAN radio ON and WiFi OFF
Profile 1 could have the WAN radio OFF and WiFi ON

Switching between these two happen based on the GPS positions

Our solution is still in proof of concept stages so once we have a good prototype we could share this concept with you.

Thanks,
Dilshan Perera
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Harry Banias
Thanks for the input and

Thanks for the input and explanation Dave.

BTW, the our AM mentioned that Intermec were out there activilty promiting that this works on their device. I think it's a bit of FUD to through us off.

If the underlying component is MSoft's Connection Manager then I can only assume the same issues would be for Intermec.

regards
Harry
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Anonymous (not verified)
Intermec has written a


Intermec has written a component for their devices that essentially does this.

I've attached a power point presentation from Intermec's Web Site which describes their solution.

We looked into "productizing" the work that we did for the trucking company as a similar offering but couldn't obtain any support for the project at the time.

We do own the source for the component that we wrote for the trucking company and it could be used to provide a head start on another project.

Dave Mohnke
Applications Support for Strategic Customers (under ECRT).
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Don Khan
Harry,          This has

Harry,
         This has been a pet peeve of mine for some time now.

I have customers who have hard coded the controls within an applicaiton, manually or process driven by the application.  Others have utilized Geofencing rules once GPS bacame available.

As David Mohnke indicated in his reply, we do have the means but need support to get this to a product offering.  I currently have a GRIP (5173-5218) submitted, requesting a comprehensive offering to combat Intermec.

Lend support to this by adding your requirement to the GRIP.
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Anonymous (not verified)
Harry,  Another possible

Harry,

 Another possible option is the Moto SSL Mobile VPN (Airbeam Safe) which supports seamless WLAN/WAN roaming as part of it's feature set although it would be an expensive solution if the customer did not need the VPN encryption functionality.

Best Regards,
Ian Hatton
EMS EMEA
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Allan Herrod
One clarification of Ian's


One clarification of Ian's statement may be of note.  the Moto SSL Mobile VPN (Airbeam Safe) does NOT handle controlling which radios are powered on and off, as was being discussed in this thread.  What the Moto SSL Mobile VPN DOES do is allow a connection to stay active when the device "roams" amongst multiple physical adapters.

So, unless you plan to leave both radios on all the time, you would still need code like that being discussed.  When combined with code to switch radios, the Moto SSL Mobile VPN would allow an application to seamlessly continue to communicate across multiple switches back and forth between the two radios.

And of course if WWAN is used, even occausionally, an application should consider the secuity (or lack thereof) of sending data over the WWAN.  The encryption of the Moto SSL Mobile VPN is highly advisable unless some other method to secure the data over the WWAN is already being used by the application.

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Harry Banias
Team, thanks for the input.

Team,
thanks for the input.

I'm obviusly not alone in this area.
At least it clarifies things for me.

BTW. I don't think the customer wants to go down the Mobile VPN path.
As a side note, they are using a private apn, so isn't that just an extension of their network on the WWAN front?

I would have thought that's rather secure as opposed to just going out to the public internet via 3G 

regards
Harry
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Anonymous (not verified)
Reviving this old thread with

Reviving this old thread with the same question...

We've got a trucking company customer interested in some method of automating the MC75A decision to use WWAN vs. WiFi (data only - no voice).  Ideally, they'd like something that would check periodically (5-15min) and switch to WiFi (disabling cellular) if their WLAN is available.  A fallback solution would be to keep WiFi enabled (they are charging in the cab, but don't know yet what the battery hit would be there...)

Any thoughts on whether Microsoft Connection Manager is now (with WM 6.5.3) robust enough to handle this kind of hand-off?

Alternately, any recommendations on 3rd party sw that might handle something like this?

Thanks,
Mike
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Juan-Antonio Ma...
I guess we still sell Airbeam

I guess we still sell Airbeam Safe, do we not?

Among other features, this product provides a secure tunnel (NOT IPsec) to communicate, and this tunnel seamlessly switches from WAN to wifi, keeping internal IP address constant.
This obviously requires a special client on the terminal (actually a virtual NIC) and a server on the other side to terminate the tunnel.


I hope this helps!
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Allan Herrod
Yes, we DO still resell


Yes, we DO still resell AirBEAM Safe, although I don't think it is currently supported on WM6.5.  And keep in mind that while it CAN provide enhanced security and virtualization of the connection and hence can allow a single connection to span changes of underlying connectivity, it does NOT represent a complete roaming solution.  You will still need to manage the radios somehow and actively participate in the decision of which radios to turn on when in order to get a reasonable result.  The WM connection manager still cannot magically decide correctly 100% of the time which radio is the best choice if both are available.  If it chooses wrong, selecting an adapter from which it cannot reach the server, then the virtual connection provided by AirBEAM Safe will not work at those time, just as if you were in an area of no coverage at all.  If/when conditions change and the adapter selected by connection manager is one via which the server can be reached, the virtual connection will begin working again.  You can make this a lot more friendly and reliably by controlling power to the radios so that only the one with the best chance of working is on at any given time.  Then the WM connection manager won't be left to choose, perhaps incorrectly, which one to use.

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Daniel Teeters
Has anyone come up with a

Has anyone come up with a better solution?  I have an MC65 customer that wants his units to switch from cellular data to WiFi when he enters his Office Areas.
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