Non T-Mobile® Devices

[global-amd]

Me and my husband have a same problem with our Treo's 650 and 680. They are both factory unlocked. Problem started in mid August on both phones. First thing that went thru my mind was that problem is with my phone because it's 3 years old but than my husbands phone is new and has same problem. It is so frustrating when you have to say "hallo are you still there, can you hear me, hallo, hallo"million times in couple of minutes. It driving me crazy called TMO so many times and complained and they answer was always it is our phone, their network is fine and so on and on. I just found this forum and I am glad that I am not going crazy, that are other people to that have same problem. I hope they will found some fix because I love my Treo and I hate to think that I will have to change the phone.

[katyk1]

O.K. we switched to the Blackberry 8320 and have had no issues.  We are keeping the Palm in hopes that something is fixed as my husband just can't stop trying to touch the sreen of the Blackberry!  ha ha ha

[acastillo]

since my last post, I have not had it happen on my Centro.  Also, my wife broke her Razr, and has been using my old 650 for nearly a week, no complaints from her, and she talks a long time on the phone.

Has anyone had any improvement?

[gregorys]

I just did some testing, and I'm still having the exact same problem, in the Portland OR area. It certainly seems every bit as pronounced as before.

Several drops of 5-10 seconds each. (They're as long as before, perhaps longer...)

-Greg

[katyk1]

Our 680 and 650 are still experiencing the same issues as of last night.

[acastillo]

I guess I'm lucky then.  I've had long calls with clients today...one was 45m and no one mentioned not being able to hear me.  My wife broke her Razr, and has been using my old 650 for a week...she hasn't mentioned a problem either, and she talks for a long time to her friends. 

We did recently go out of state last Wed, which coincidentially is the length of time our phones have been behaving.  Didn't I read someone in FL also going out of his local network and seeing an improvement?

[carguy]

I drove from Tallahassee, FL to Tampa, FL via Gainesville, FL on Sunday morning. I took I-10 and I-75. I used my Centro during the drive and found that the problem with people not being able to hear me seemed to start once I was off of I-10 and on I-75 headed south toward Tampa. I did not have the problem a single time in Tallahassee, FL. I thought it might have something to do with T-mobile's 3G coverage roll out, but after looking at their coverage map, that doesn't seem to be the case. Does anyone know if they've added 3G coverage on I-75 without adding it to their coverage map? If you don't know if it's true for that area, does anyone know if it's true in general that T-mobile is expanding 3G onto major highways near cities with 3G? 

I'll probably call T-mobile sometime later tonight and complain a bunch. I'd switch to a T-mobile Android phone if T-mobile didn't require an expensive plan along with their smartphones. I'd even buy another unlocked phone, but I can't find anything I like that's compatible with T-mobile's 3G network. I'd hate to spend a bunch of money on an already outdated phone. 

[adanziger]

I've been doing a lot of reading and asking a lot of questions. There have been a great many changes made to what we just think of as GSM. This might bore you but read these following paragraphs and you'll see what I'm talking about:

In the 900 MHz band the uplink frequency band is 890–915 MHz, and the downlink frequency band is 935–960 MHz. This 25 MHz bandwidth is subdivided into 124 carrier frequency channels, each spaced 200 kHz apart. Time division multiplexing is used to allow eight full-rate or sixteen half-rate speech channels per radio frequency channel. There are eight radio timeslots (giving eight burst periods) grouped into what is called a TDMA frame. Half rate channels use alternate frames in the same timeslot. The channel data rate is 270.833 kbit/s, and the frame duration is 4.615 ms.

GSM has used a variety of voice codecs to squeeze 3.1 kHz audio into between 5.6 and 13 kbit/s. Originally, two codecs, named after the types of data channel they were allocated, were used, called Half Rate (5.6 kbit/s) and Full Rate (13 kbit/s). These used a system based upon linear predictive coding (LPC). In addition to being efficient with bitrates, these codecs also made it easier to identify more important parts of the audio, allowing the air interface layer to prioritize and better protect these parts of the signal. A codec is a device or program capable of encoding and/or decoding a digital data stream or signal. ... Half Rate or HR or GSM-HR is a speech encoding system for GSM developed in the early 1990s. ... Full Rate or FR or GSM-FR was the first digital speech coding standard used in GSM digital mobile phone system.

GSM was further enhanced in 1997 with the Enhanced Full Rate (EFR) codec, a 12.2 kbit/s codec that uses a full rate channel. Finally, with the development of UMTS, EFR was refactored into a variable-rate codec called AMR-Narrowband, which is high quality and robust against interference when used on full rate channels, and less robust but still relatively high quality when used in good radio conditions on half-rate channels.

I mention this so that you can understand that there are many different "implementations" of GSM. There are 124 channels available, there are 1/2 rate and full rate channels, and a bunch of different codecs. If T-Mobile has upgraded some of their towers to the new codecs and the phone your using doesn't support it, or if the tower, to avoid interference switches channels on you in the middle of a conversation, to a channel that your phone doesn't support, you will have silence on one end until it changes channels again to something that your phone supports. T-Mobile only supplies phones that it fully supports. Some of them causing trouble like Palm Centros and others may not have every codec or frequency available that T-Mobile is using.

You're not going to be able to get help if this is your problem from Customer Care, it's going to take someone in their engineering department and even then, I'm not sure that they'll ever be able to help you. I'm also not certain that this is the problem but I think I'm getting close.

[djkieras]

Thanks for the information.  One wonders, though, why only the Palm user's voice always is the one dropping.  Is your hypothesis that only the uplink channel that is switching on us?  Is that perhaps why my test of a constant sound source didn't exhibit the problem, but with speech (and the silence breaks between words) allowing an opportunity to switch channels?  And what's your hypothesis of why this problem does not occur on AT&T?  And why don't any other phones exhibit this issue, even older ones like the dinosaur Sidekick that my wife is using?  Perhaps Palm has some wonky implementation of GSM?  [So many questions, I know...]

I talked to T-Mo support yesterday and they pretty much explained to me that they know the network changes that caused the problem, and they claim it is only Palm devices.  (I referenced the support ticket in gregorys' post...they said it wasn't a trouble ticket but a support ticket or some such thing.)  They said they've reported it to Palm.  <sigh> 

Several on this thread are getting replacement Centro phones from Palm.  Gregorys was postulating that Treo and Centro were EOL products.  However, if Palm still is _selling_ the Centro and sending replacements, and since it still is featured on their web site, one hopes they _will_ release a software update...and quickly.  Treo users, probably not so much.  Unless, of course, it's a shortcoming of the hardware...which could explain why gregorys ultimately received a Treo Pro.

[adanziger]

I made a long post on the other thread running concerning this with the exception directly answering a couple of the questions you posed here. I won't repeat what I wrote there but will answer your specific questions.

As you have correctly deduced, the phone transmits and receives on different frequencies within the allotted spectrum. I believe that the uplink frequency that it's switching to is not supported on your Palm, but it's possible that it could switch to an unsupported downlink channel as well. I don't know what channels are and are not supported on your Palm. I don't know if it will switch channels in the middle of a sentence or if it waits for silence to do so.

The Sidekick is a T-Mobile device and was purposely designed for T-Mobile's system, supporting current and anticipated near term future upgrades to that system. Just the fact that network changes (which of course are upgrades, not downgrades) caused these problems supports my hypothesis.

[dessa]

Hey, adanzinger, can you post a link to that other thread please? 

I tried searching, but keep getting this thread.

thanks!

[gregorys]

It's here:

http://forums.t-mobile.com/tmbl/board/message?board.id=General&message.id=5176#M5176

[satelias]

I am so glad I found this thread, I thought I was going nuts, bought a new Centro and BT headset and its still a problem. 

One more testing question!   

I just realized that the problem happen today only on some calls I made and not calls that I received. 

Has anyone confirmed or disproved this?   

Thanks

Scott

[djkieras]

It happened to me with calls I both made and received.

[acastillo]

hmmm, it's interesting that while I was plagued with the problem before, it still has not reappeared since my post 2 days ago...

[gregorys]

First) Problem is still present in the Portland OR market.

More interesting

Just FYI:

I got a call from a nameless TMob employee...not exactly sure what his job title is...but

Paraphrase of the message he left.

Bad news) All the Treo's and Centro's evidently have the problem. Since TMob doesn't have much of a relationship with Palm, it's not likely Palm will issue a fix themselves.

Good new [at least potentially]) TMo is aware that the problem *is* occuring on TMo branded handsets now too. So, provided it's a big enough problem it might get addressed by further changes on the TMo network. These changes might "fix" the problem on the Palm phones.

No ETA for when this might actually get done etc, but interesting non-the-less.

Finally, I believe from some notes from my case that were read to me, that the "BTS-SW" upgrade caused the problem. It's my opinion that the only "upgrade" that was possible is one to TMo's network.

If anyone knows what the BTS-SW upgrade is/was - please tell!

-Greg

Message Edited by gregorys on 09-30-2009 06:50 PM

[adanziger]

Here's a link to more information than you ever wanted to kow about the BTW-S/W upgrade. It's very engineering oriented but to summarize it simply, it's related to 3G upgrades now and 4G down the road, and it's for improved efficiency in switching, data carrying and energy usage.

http://www.nokiasiemensnetworks.com/NR/rdonlyres/9DD8041D-DD13-424E-BDA2-6F034787D5D8/0/Flexi_multir...

[gregorys]

Ok, I now understand the problem. I spoke with an RF Engineer about it.

There was a BTS upgrade to the system - perhaps not in all markets - but in mine, and I would assume everywhere where the problem exists...that upgrade was applied by TMobile about five weeks ago. [This also explains why some users report that the problem ceases when they travel outside of their "normal" use area. Those areas may not have base-stations by Nokia / Siemens, or perhaps don't have the same software revision that exposes the problem.]

The real issue is due to a "feature" called DTX - or Discontinue Transmission. In essense it allows either end to "discontinue" transmitting when there's a silence. In short, the phone recognizes that you're not talking and enters DTX mode. This means it doesn't have to transmit on the radio during the time DTX is enabled, thus saving power. The phone is supposed to recognize when you start talking again, and signal the base station to discontinue DTX mode.

For some reason, DTX mode isn't discontinued when you start talking again and the uplink radio traffic is either lost or doesn't occur. Since DTX isn't new, one would assume that it worked properly before, and that some interaction in the new base station upgrade has revealed some interoperability problems.

Normally the carrier could release updates to a phones firmware - because they would have access through the vendor. This gets into a grey area, I expect, as to what's possible etc. But suffice it to say that I expect TMo isn't exactly excited about spending time and money on a fix to the handset they never sold or promised to support - even if Palm would allow them to modify the firmware (which Palm might well not agree to).

Palm doesn't want to spend any resources themselves on Palm OS when it's dead and gone and they're trying to get WebOS going and keep the company alive. [And I've been told as much by Palm.]

However, as I said before, this DTX problem does occur on some other handsets - ones TMo sold. Thus, they'll want to address these handsets.

The wrinkle is this. They can address the interoperability problem in either of two ways.

1) They can update the software in the handset so it doesn't end up in a faulty DTX mode in relation to the base-station.

2) They can pressure Nokia / Siemens (that page link above is now dead – go figure) to re-work the software in the base-station, also to improve the interoperability problem.

For those of us with Treos and Centros – the first solution will leave us out in the cold. The second has a good chance of fixing it for us.

But I don’t know how urgent TMo feels the problem is, and how they’re leaning to fix the problem. If they only have a few handsets with the problem – and they can get the problem to go away by making people upgrade etc – they’ll probably choose option 1. It would be a lot cheaper and easier I expect.

If they get a boat-load of problems, or Nokia/Siemens has a rash of problems with the base-station software – we may get option 2.

If I were a betting man, I think I’d put the odds right now of the fixes as 60-70% likelihood on option 1, and only 30-40% on option 2.

---

Also, to get the problem to go away – pause in taking a bit, and start talking again. The transition into and out of DTX mode on the handset again will likely cause it to reset the DTX state properly – and they’ll be able to hear you again.

---

The whole issue is rather fascinating and a rather stark lesson in interoperability issues.

I’m glad to follow-up as you have questions!

-Greg

Message Edited by gregorys on 10-02-2009 10:41 AM

[global-amd]

My and my husband still experience thisintermittent voice on our Treos 650 and 680. Couple of days ago it was little bit better(two days without problems) and I tough that TMO fix the problem but they did not. It is very bad and I have a feeling that dropouts are longer now. We live in Largo ( Tampa bay area ) and couple of my friends have a same problem with Treo. I use my phone(it has infrared port) for real estate and for unlocking electronic lock boxes on properties and it is very important for me that is working properly. No TMO phone supports infrared post that I desperately need. That is why I purchased Treo and I been using it for years and now this.......?????

[RALTMAN]

Ok, I just got off the phone with Palm corporate and they have told me that it is not palm. It has to do with the T-mobile upgrade that it going on with the 3G technology (if I got that technology phrase right). That it is a role out throughout the country and that some cities will have the total change over completed before others. The individual I spoke with at Palm said that he was experiencing the same problems with his Palm and T-mobile. A technician he was speaking with told him to have T-mobile issue him a 3G sim card and that should solve the problem. Has anyone tried a 3G sim card to solve this problem?