Thursday, May 06, 2010

Why is AT&T's MicroCell Dropping Calls?

AT&T's Mini Home Cell Phone Tower

Apparently AT&T Microcell users are getting LOTS of dropped calls after installation of the AT&T Microcell / Femtocell after a proper installation.  Does there need to be more disclosure about which cable and wireline network the Microcell works best with?  Can Comcast, Cox, Time Warner, Cable Vision purposely sniff out AT&T Microcell packets and make the calls drop similar to Vonage and Skype?  It also appears that there is a not so friendly competition between the Microcell and the macro cell tower outside for domination. If the macro cell tower strenght is too strong, the microcell hands off the call. Once that happens it cannot go back. If your call is in macro and the signal starts to degrade, you end up with a dropped call.  Why does this happen?  Well RF engineers tell us it's because the cell tower outdoors doesn't know the Microcell exists on the network and thus your the signal will not be optimized.  Sometimes too many cell phone towers or Microcells in an area can cause dropped calls as well.

Here is are 3 examples of a users having problems:

San Francisco - All the lights are on and my iPhone reads AT&T M-CELL with 5 bars all over the house.  I've got a 50MBit down/10MBit up connection which passes all the VoIP online tests with flying colors (very little jitter, 0.0 packet loss etc..) It's hooked to a reasonably new dual channel Cisco wireless router.  The problem is that Calls are failing all the time - while the bars stay solid at 5. Occasionally, I'll go a day or two without a dropped call, but then I'll have 5 or 6 dropped calls in a row. I've had to disable 3G on the iPhone just to maintain a conference call for more than 10 minutes without dropping. I've restarted it a couple of times and that doesn't appear to do anything.

San Diego - I've had my MC for a couple of weeks now. Where I live in San Diego, it is very hilly. Macro cell coverage is very spotty. In the front of my house, I get absolutely no bar coverage. In fact it typically says "Searching for Network". In the back of my house approx 50' away I get 1-2 bar macro coverage. I have experimented with the location of the MC and here is what my very superficial testing has shown. It seems to be important to locate the MC in a location where you get the worst macro cell coverage. It somehow appears, that there is a not so friendly competition between the MicroCell and the cell tower for domination. If the macro cell strenght is too strong, the microcell hands off the call. Once that happens it cannot go back. If your call is in macro and the signal starts to degrade, you end up with a dropped call. So now with the MC located in the front of my house, I get 5 bar coverage and almost never drop a call throughout most of the house. However, if I start a call up front and start walking towards the rear, once the tower strength starts to exceed the MC strenth that appears to be the problem area. If it hands off to the cell tower I typically have no better than 50% chance of completing the call before it is dropped.

Salt Lake City - I just bought a MicroCell yesterday in Salt Lake City and had my first two calls dropped. So far, I'm less than impressed. Let me know if you or anyone has any suggestions. If not, this might be a short-lived purchase.

Is anyone else experiencing this kind of performance? Is there a firmware update of some kind?

Read more at the AT&T Wirless Forum

Related Posts:
Call Failed or Dropped Calls?


  1. AnonymousMay 20, 2010

    I'm having the same issue (in Massachusetts).

    Installed Microcell yesterday: I don't drop a call as long as I'm in the same room as Microcell, but as soon as I venture just 10 feet away, I will drop my calls within a minute or two.

    Doesn't seem to be related to my ISP, since it's dependent on distance from Microcell. And, my phone never hands off to the Macro.

  2. I'm having this issue as well (Portland, Oregon). Installed in about 20-30 minutes. I have had 3 dropped calls so far. Microcell is behind my Plasma TV. I have had two dropped calls up stairs, but with 5 bars, and I have had one dropped call downstairs, about 20 feet from the Microcell.

    At times the call quality is excellent and others it is very robotic. This seems to vary depending on where I stand in a room. I haven't done a lot of tests yet. My initial impression is not so good. I expected a rock-solid signal pretty much everywhere in my house.

  3. I installed my AT&T microcell last week (both options A and C). Call dropping rate exceeds 50%. We have Comcast cable, on which Skype and other VOIP work as well.

    There are LOTS of postings about this problem at the ATT wireless forum, and little suggestions for improvement.

  4. AnonymousJuly 08, 2010

    Having this same problem in San Francisco. Apple IPhone 3GS, 2 week old Microcell. 45M/sec up and down connection. Come on AT&T. So lame.

  5. AnonymousJuly 09, 2010

    Worked w/ ATT this AM. Reregisterd my microcell. No joy. Tech resent my SIM card settings and it fixed it. Said you can accomplish the same by removing your SIM for about 5 MIN and then reinstall. Should pull down your settings. Haven't tried to leave the microcell coverage area and come back to see if it still is resolved but for now, its working as advertised.

  6. AnonymousJuly 21, 2010

    I purchased a MC in San Mateo, CA in mid-June. The unit suffered from terrible call latency (noticeable delay in speech), and more times than not I could not make a call due to a "No Circuit/Channel Available" problem. After three weeks I took it back and got a replacement. I've had the new unit for a week now and it seems to work fine. I have separated the MC from my dsl modem and wifi router by about 15 feet. Also configured MC in priority mode.

  7. AnonymousJuly 23, 2010

    I had the microcell for about two weeks (colorado). I noticed one day that every call got dropped. I called AT&T, they opened a trouble ticket. I called back every day. They are still working on it. Called one day and they said that they were experiencing a microcell outage. Next day, outage over, my calls are still dropped. I finally called up an AT&T retail rep. He checked for me and gave me some vague info about IP conflict. A day later the calls started going through. Total outage 10 days.

  8. I have the very same trouble in downtown Anaheim ... I've had the m-cell for about 6 weeks as the new neighborhood I moved to has terrible AT&T coverage (Note I'm two blocks from a large AT&T service center :-/) I get full bars but calls just get dropped - usually the voice on my call gets hard to understand and somewhat garbled before the call is dropped - other times not. Sometimes I also don't get calls when connected to my m-cell and sometimes voice mail and text messages come in in groups much later than received.

    Pretty much terrible and not reliable ... unfortunately it's the only way I can get service here ...

  9. AnonymousJuly 24, 2010

    Same problem in New Jersey. Audio quality is generally higher with microcell, but drops calls furiously even though I have a Verizon FiOS 25 down 25 up.

    Anyone figure out what the problem is yet?

  10. I live in portland TN and I am also having the same problem with dropped calls. AT&T doesn't have a clue and they have been working on it for 30 plus days. I have comcast so I not my Internet is fast enough. Also I have forwared all my ports that are required for the microcell.

  11. I'm having the same problem with dropped calls both on a IPhone 4G, and Blackberry Bold, on Comcast with a new WNR3700 router. I've set up the Femtocell so that it has priority on the network, but calls are still dropped suddenly.

    On the other hand, my comcast voip work beautifully, and skype from my iphone works great too.

  12. Santa Clara, CA - never had good AT&T coverage in my house. Have AT&T DSL service at home. I typically have lots of long conference calls at home on my iPhone and usually have to sit right next to a window to get some coverage. Bought an AT&T MicroCell about a month ago and connected it just fine. Got five bars throughout my house, but the call quality was TERRIBLE. Much worse than before, even though I only had a single bar without the device. I could barely make out any of the conversation on the calls. If I moved to within 5 feet of the MicroCell, the call quality got a little better, but that's not a viable solution. I ended up returning the MicroCell three days later.

    So, very poor call quality even though:
    1. On an AT&T DSL line, so nothing to do with ISP
    2. Showing five bars everywhere in the house
    3. Has nothing to do with Internet bandwidth since call quality was good when I was sitting next to the device

  13. I've had the microcell since it was rolled out in Ohio and have still been dropping calls. I've spoken to technical support on multiple occasions, each time they promise to research the issue and get back to me. I wont hear back from them and when I call back, they tell me their notes show that the matter has been resolved because they tried to contact me and didn't get a hold of me. When I spoke to them this evening (after I first dropped a call while on hold) I told them I expected a solution by there promised date of this friday, or I expected to be permitted to get out of my contract at no charge. I was informed that because I have been under my now contract for too long they do not have the authority to let me out at no charge. I politely informed them that the only reason I stayed with them this long is that I was promised to microcell would solve my problems. Unbelievable. Any way, Ive run internet speed tests and everything is find; I have my modem going directly to the microcell before the router; and I get full bars in a number of places in my house, but as soon as I place a call, the voices soon sound like robots and I often times drop the call.

  14. I have a m-cell and I can only use my phone it that room. Either the other person sounds like they are talking under water or the call drops. I run a business from home and this is annoying. I live in West San Jose. Although I get reception in the one room it still drops calls. Do I need another m-cell or a new phone. I have a 3G iphone.

  15. Sunnyvale, CA...had microcell for 3-4 months. first month, not many dropped calls (5 bars always). now, constant dropped call with 5 bars. So, now it is turned off and living with 1-2 bars on regular tower. WHAT A JOKE. switching to Verizon/Sprint when my contract is up. Had sprint for 12 years prior and never had dropped call. only switched for iphone 4.

  16. Same problem in Connecticut. Now in addition to dropped calls, I'm unable to place or receive calls at times. Re-booted the Microcell. Sometimes it works, sometimes it doesn't. This is ridiculous and they should be fined for false advertising, charging for services not rendered, etc.

  17. I'm having the same issue in New Jersey.


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