Jump to content

Evo 4G LTE -> 3G issue?


bmoses

Recommended Posts

good morning everyone! so i got a new EVO 4G LTE last week and so far have been loving it, huge improvement over the original EVO that i had before!

 

However i have been noticing a small issue with the 3G connection. Using the CDMA field test app to look at the signal strengths of both CDMA and EVDO i can tell for the most part that both voice and data are either connected to the same tower or not. What i have noticed is that when i'm driving or going form one area to another voice will quickly switch to a new tower when the signal gets to low from the tower it was connected to, however 3G seems to stay connected to the previous tower until it doesn't have signal anymore.

 

i've seen it get as low as -118db for signal strength and then it finally loses connection. Then when it does lose connection to the old tower it seems like it takes a little bit to finally connect to the tower that is closer. and if it happens to pickup a signal from the old tower before it switches to the new it will connect back to that one again!

 

Has anyone else noticed this on their phones? I have another week for my 14 days and i'm just trying to figure out if its just how the phone is or if mine is having an issue and i need to go exchange it.

 

Thanks!

 

PS i'm in a third round market so no 4G for me for awhile :(

Link to comment
Share on other sites

This happens all the time if you are actively using 3G data. Phone doesn't want to hand off an active data session it is actively using until it has to, especially streaming. I bet if you stopped using data for a moment, 3G would switch sites.

 

Robert via CM9 Kindle Fire using Forum Runner

Link to comment
Share on other sites

hmmmmmm when i was watching it while driving this morning i wasn't actively using data, unless something was going on in the background. Was just watching the signal numbers between CDMA and EVDO waiting for EVDO to switch over to the tower that CDMA was connected too. I will watch for that though and see if thats the case. thanks!

Link to comment
Share on other sites

Whilst watching for those data signals to switch please don't neglect watching for those traffic signals to switch or for one of your fellow drivers to lane switch.

 

Maybe Sprint should make a version of those "this is the text I was sending" ads. "This is the speed test I was running when I slammed into those kids crossing the street. Their parents didn't understand that their children are dead because I just had to check out my data connectivity. Now I just get 1x on the phone my cell-mate smuggled in."

  • Like 2
Link to comment
Share on other sites

bmoses could be experiencing the EV-DO hashing issue that I describe in this paragraph of my recent article on The Wall:

 

Another benefit of rehashing to a different carrier channel is that you may be able to connect to a closer cell site. Because not all cell sites have the same number of deployed EV-DO carrier channels, carrier channel hashing is an imperfect process. To illustrate, the cell site (call it cell site "A") that I detailed above for this trial has three EV-DO carrier channels (F1, F2, F3), as duly noted. But the adjacent cell site to the north (call it cell site "B") has only two EV-DO carrier channels (F1, F2). A handset that hashes to F3 on cell site "A" will cling to carrier channel PCS 0175 even as it moves north well into the coverage area of cell site "B." Interference will not be a problem, as cell site "B" does not transmit PCS 0175, but signal strength (and data speeds) will diminish until cell site "A" drops below a network defined threshold, at which point the handset will handoff to cell site "B" and hash to PCS 0150. This can require substantial movement and/or time. So, if you always want the most crisp EV-DO handoffs, you can try to ensure that your handset always hashes to F1, the EV-DO carrier deployed on essentially every site in the market.

 

http://s4gru.com/index.php?/blog/1/entry-318-can-toggling-airplane-mode-actually-improve-your-3g-data-speeds/

 

AJ

  • Like 1
Link to comment
Share on other sites

bmoses could be experiencing the EV-DO hashing issue that I describe in this paragraph of my recent article on The Wall:

 

 

 

http://s4gru.com/ind...3g-data-speeds/

 

AJ

 

AJ i bet that is it, thanks! and i'm guessing that the original EVO didn't have this issue as much since it didn't have two antennas for SVDO, so whenever CDMA switched then EVDO switched?

 

and don't worry, was in an area with no traffic and no pedestrians, was on a mile long bridge going across a lake :)

Link to comment
Share on other sites

AJ i bet that is it, thanks! and i'm guessing that the original EVO didn't have this issue as much since it didn't have two antennas for SVDO, so whenever CDMA switched then EVDO switched?

 

I doubt that SVDO capability is related because even non SVDO handsets track CDMA1X and EV-DO PNs separately. While idle, non SVDO handsets just alternate back and forth between monitoring CDMA1X and EV-DO.

 

Does the idle EV-DO delay in switching PNs happen with every site all the time? If so, then you may have a defective handset. But if it happens with only some sites some of the time, then I would put my money on the EV-DO channel hashing lag that I detailed in the article.

 

AJ

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • large.unreadcontent.png.6ef00db54e758d06

  • gallery_1_23_9202.png

  • Posts

    • Fury Gran Coupe (My First Car - What a Boat...)
    • Definite usage quirks in hunting down these sites with a rainbow sim in a s24 ultra. Fell into a hole yesterday so sent off to T-Mobile purgatory. Try my various techniques. No Dish. Get within binocular range of former Sprint colocation and can see Dish equipment. Try to manually set network and everybody but no Dish is listed.  Airplane mode, restart, turn on and off sim, still no Dish. Pull upto 200ft from site straight on with antenna.  Still no Dish. Get to manual network hunting again on phone, power off phone for two minutes. Finally see Dish in manual network selection and choose it. Great signal as expected. I still think the 15 minute rule might work but lack patience. (With Sprint years ago, while roaming on AT&T, the phone would check for Sprint about every fifteen minutes. So at highway speed you could get to about the third Sprint site before roaming would end). Using both cellmapper and signalcheck.net maps to hunt down these sites. Cellmapper response is almost immediate these days (was taking weeks many months ago).  Their idea of where a site can be is often many miles apart. Of course not the same dataset. Also different ideas as how to label a site, but sector details can match with enough data (mimo makes this hard with its many sectors). Dish was using county spacing in a flat suburban area, but is now denser in a hilly richer suburban area.  Likely density of customers makes no difference as a poorer urban area with likely more Dish customers still has country spacing of sites.
    • Mike if you need more Dish data, I have been hunting down sites in western Columbus.  So far just n70 and n71 reporting although I CA all three.
    • Good catch! I meant 115932/119932. Edited my original post I've noticed the same thing lately and have just assumed that they're skipping it now because they're finally able to deploy mmWave small cells.
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...