Handoff Native to Roaming?

[owensri2]

An interesting thing happened while I was leaving work today and heading home. I just recently moved to Charlotte, NC (Matthews, suburb). I started a call on the Sprint network in Hartsville, SC, and figured that it would drop once I drove out of Sprint native coverage and the call continued. I decided to look at the display, and it showed that I was roaming! I didn't know that it was possible.

 

The roaming area I drove into is US Cellular. Any ideas? This is the first time that I didn't drop a call while going from Native coverage to Roaming.

[Steven800]

I usually don't drop a call going from native to roaming.

[JeffDTD]

Are u positive you started the call in sprint coverage and were not roaming when rhe call started? Ive seen my galaxies roam and hang on to the roaming network even once they are back in native.

[owensri2]

Are u positive you started the call in sprint coverage and were not roaming when rhe call started? Ive seen my galaxies roam and hang on to the roaming network even once they are back in native.

 

I am 100% positive. I looked at the signal, and I was near the Sprint tower in Hartsville when I initiated the call.

[jefbal99]

I can't say I've ever had that happen, however, my roaming in MI is Verizon 850, so the switch from Sprint 1900 is most likely a hard handoff. Perhaps it is a soft handoff due to US Cellular using 1900 spectrum in your area?

 

We need AJ to chime in here

[S4GRU]

In my area, the only PCS roaming is Cricket and Commnet. I cannot ever handoff to Sprint or vice versa on these. If I start a conversation on any of these two, I will stay connected to that network, even if I drive into Sprint coverage.

 

It's extremely problematic on Commnet, as they have poor coverage inside Sprint coverage areas. They tend to place sites outside of Verizon/Sprint coverage to sell roaming to them. So I will get dropped when the roaming signal finally runs out, and then I have to wait for my device to scan and connect to Sprint native or another roaming carrier to call back and continue.

 

Also, in my area, we have old Alltel and Verizon roaming on 850 Cellular. These never hand off to anything.

 

When making an outgoing call when roaming, I have to check which carrier I'm on first. Then I have to decide if that carrier has continuous coverage along my route, knowing it will not handoff to another roaming carrier or to Sprint. In many instances while roaming, I will cycle airplane mode to get a better carrier. Because Commnet is really bad for me as none of their sites overlap. So I cannot keep a phone call from one site to the next. I try to get Verizon as much as possible so I can keep the conversation as long as I need to.

 

When I get an incoming call while roaming, there is nothing I can do. I just warn the caller that I may lose service and that I'll call them back. I pretty much know every roaming seam in all of Northern New Mexico.

 

Robert via Nexus 7 with Tapatalk HD

[WiWavelength]

I can't say I've ever had that happen, however, my roaming in MI is Verizon 850, so the switch from Sprint 1900 is most likely a hard handoff. Perhaps it is a soft handoff due to US Cellular using 1900 spectrum in your area?

 

We need AJ to chime in here

 

No, soft handoff is possible only on the very same carrier channel. Plus, USCC has substantial Cellular 850 MHz footprint in the Carolinas.

 

So, if this handoff really did happen as described, it was almost certainly an inter band, inter MSC hard handoff. I would like to see it demonstrated again to show that it is repeatable. Then, we could examine how it is possible.

 

AJ

[jefbal99]

When making an outgoing call when roaming, I have to check which carrier I'm on first. Then I have to decide if that carrier has continuous coverage along my route, knowing it will not handoff to another roaming carrier or to Sprint. In many instances while roaming, I will cycle airplane mode to get a better carrier. Because Commnet is really bad for me as none of their sites overlap. So I cannot keep a phone call from one site to the next. I try to get Verizon as much as possible so I can keep the conversation as long as I need to.

 

Robert via Nexus 7 with Tapatalk HD

 

How can you tell what carrier you are on before cycling airplane mode to another?

[S4GRU]

 

How can you tell what carrier you are on before cycling airplane mode to another?

 

I use NetMonitor. It's the fastest way to find out.

 

Robert via Nexus 7 with Tapatalk HD

[WiWavelength]

How can you tell what carrier you are on before cycling airplane mode to another?

 

Gotta know your local SIDs, baby. And that, appropriately enough, is going to be the focus of my next engineering screen article. I am thinking of calling it "SID and NIDsy." Anybody get this music reference?

 

AJ

[jefbal99]

Gotta know your local SIDs, baby. And that, appropriately enough, is going to be the focus of my next engineering screen article. I am thinking of calling it "SID and NIDsy." Anybody get this music reference?

 

AJ

 

I'm guessing its a Sid Vicious/Sex Pistols reference?

[owensri2]

Just reproduced the handoff again on my way home. I started the call on Sprint, and it handed off to US Cellular!

[jefbal99]

Just reproduced the handoff again on my way home. I started the call on Sprint, and it handed off to US Cellular!

 

I'd love to see engineering screenshots before, during, after handoff, and hangup

[WiWavelength]

Just reproduced the handoff again on my way home. I started the call on Sprint, and it handed off to US Cellular!

 

The only way that is possible is if their MSCs are harmonized. And I am not aware of that elsewhere, so it seems out of place here.

 

I suppose one possibility is that -- because this area outside of Charlotte is a former affiliate market -- AirGate PCS could have contracted to use USCC's MSC as its own. But even if that were the case, I would have expected Sprint to take that in house with its affiliate acquisitions several years back.

 

AJ

[owensri2]

Here's the Sprint coverage map of the subject area:

 

handoff by rrxingmtr, on Flickr

[Bob Newhart]

When Sprint 800 Mhz CDMA is launched for us to use, will the voice calls change from 800 to 1900 to 800 on the fly?

[jefbal99]

When Sprint 800 Mhz CDMA is launched for us to use' date=' will the voice calls change from 800 to 1900 to 800 on the fly?[/quote']

 

Robert observed this when doing his field testing in Austin

 

Sent from my cm_tenderloin using Forum Runner

[bigsnake49]

CDMA provides for intercarrier handoffs. The American CDMA carriers never implemented it.

[owensri2]

Happened again today.  Started on Sprint, 6 bars near the tower.  I initiated a call and it ended up on US Cellular.  I looked at the screen after I had figured the call would have dropped, and the little roaming triangle appeared as soon as the display turned on.  The SID before the call was 4376.  I checked SignalCheck during the call after it had switched to roaming and it was 1648.  Any ideas on who the SID's belong to?  I would assume 4376 is Sprint, but not sure about the 1648 (US Cellular). 

[WiWavelength]

Any ideas on who the SID's belong to?  I would assume 4376 is Sprint, but not sure about the 1648 (US Cellular). 

 

Are you sure that you did not read it incorrectly?  SID 1643 is USCC.

 

AJ

[owensri2]

Are you sure that you did not read it incorrectly?  SID 1643 is USCC.

 

AJ

 

Sorry, you're right.  1643 is correct.

[halcyoncmdr]

The only way that is possible is if their MSCs are harmonized. And I am not aware of that elsewhere, so it seems out of place here.

 

I suppose one possibility is that -- because this area outside of Charlotte is a former affiliate market -- AirGate PCS could have contracted to use USCC's MSC as its own. But even if that were the case, I would have expected Sprint to take that in house with its affiliate acquisitions several years back.

 

AJ

 

Perhaps related to the Sprint/USCC customer and spectrum transaction? Just throwing it out there as a possible reason, no idea myself.

[GonzoRocks]

In my area, the only PCS roaming is Cricket and Commnet. I cannot ever handoff to Sprint or vice versa on these. If I start a conversation on any of these two, I will stay connected to that network, even if I drive into Sprint coverage.

 

It's extremely problematic on Commnet, as they have poor coverage inside Sprint coverage areas. They tend to place sites outside of Verizon/Sprint coverage to sell roaming to them. So I will get dropped when the roaming signal finally runs out, and then I have to wait for my device to scan and connect to Sprint native or another roaming carrier to call back and continue.

 

Also, in my area, we have old Alltel and Verizon roaming on 850 Cellular. These never hand off to anything.

 

When making an outgoing call when roaming, I have to check which carrier I'm on first. Then I have to decide if that carrier has continuous coverage along my route, knowing it will not handoff to another roaming carrier or to Sprint. In many instances while roaming, I will cycle airplane mode to get a better carrier. Because Commnet is really bad for me as none of their sites overlap. So I cannot keep a phone call from one site to the next. I try to get Verizon as much as possible so I can keep the conversation as long as I need to.

 

When I get an incoming call while roaming, there is nothing I can do. I just warn the caller that I may lose service and that I'll call them back. I pretty much know every roaming seam in all of Northern New Mexico.

 

Robert via Nexus 7 with Tapatalk HD

Make a custom PRL that lowers priority or gets rid of the Commet towers altogether.

 

 

I might be making a quick tut on that soon.

 

 

[owensri2]

Well, since about the beginning of August, I am no longer able to handoff from native to roaming.  The call drops like it did before.  Strange...

[WiWavelength]

Well, since about the beginning of August, I am no longer able to handoff from native to roaming.  The call drops like it did before.  Strange...

 

The mysterious handoff over the summer must have been due to sunspots, a coronal mass ejection.

 

AJ