02-18-2013 8:49 AM
While I didn't encounter this problem initially when I started up my Mcell a few months ago, it has now become a daily ritual that I hope someone here can help me with.
Motorola SB 6120 modem -> Netgear WNR3500L router -> Mcell
The Mcell is connected to the router with a pair of Netgear Powerline 200 Nano Adapters because my modem and router are located in the basement with no exposure to window for the Mcell to see a GPS satellite. The connection is good.
My Charter ISP connection is 30 mbps down and 4 mbps and is rock solid.
What's happening and what I've done so far:
Usually once a day I will no longer see the AT&T Mcell indication at the top of my iPhone 5. When I check my wife's iPhone 4S she has also lost the AT&T Mcell indication.
Turning the phones off and then on does not bring back the Mcell connection. Switching Airplane Mode off and then on does not bring back the Mcell connection.
The Mcell has all solid green lights when I go to check it after seeing the lost connection. If I power cycle the Mcell, the phones will then show an Mcell connection again until the next time they lose the connection which is usually once/day but not at any particular time.
I have the latest firmware on all devices.
When I check my router's admin page after a lost connection, the router indicates that the Mcell's IP address has not changed and it remains the same after power cycling the Mcell.
On the WAN page for my router, I have set the MTU size to 1492 and set the NAT Filtering to "Open" instead of "Secured". No improvement after doing so.
Suspicious of the Powerline Adapters, I tried disconnecting and reconnecting the Ethernet cable from the Mcell to the Powerline Adapter to mimic a temporary loss of connection to the router to see if that affected the Mcell connection. The Mcell connection was not lost.
I have not set any open ports or a static IP address for the Mcell yet. Is what I'm experiencing indicative of this solution? Does anyone have any other thoughts as to what try next?
I don't want to waste my time with an AT&T Level 1 tech support person because their suggestions are almost always worthless. I have better luck contacting user forums and that is why I'm posting here.
Thank God I was able to convince AT&T to give me a Mcell for free because if I paid $200 for it, I'd be very upset right now.
Thanks In Advance!
07-23-2013 8:54 AM
PowerLine Adapters are #3 on the list of items to discuss with support tonight on our conference call. It will be interesting to see what they have to say. Thanks for the timely update. I always felt that your issue was related to the PowerLine Adapters but unfortunately it took a lot of troubleshooting on your part to determine that. The MicroCell must be very sensitive to line fluctuations that otherwise doesn't noticeably affect the rest of the internet connnection.
- edited 07-23-2013 10:51 AM
You might trying pressing the "experts" for a reason why this is the case. I'd sure like to know what their answer is...if they even have one.
I've been pondering this for a bit and I can think of a few things. I know enough electrical engineering to be dangerous but after doing a little research, one thing that I can think of off the bat is the fact that U.S. homes are provided with 240 VAC...with two 120 VAC phases coming into the house. The two phases are combined to provide 240 VAC where needed (dryers, ranges, etc.) and the two 120 VAC phases provide 120 VAC power to various parts of the house. I think a potential problem could be if one Powerline adapter is on one node (or phase), while the second adapter is on the other. Communicating between the two phases shouldn't be an issue unless there is a problem back at the power company's transformer. I've read that this can be overcome by installing a .1mfd 400v capacitor across the two phases but I'm not about to mess with something of that nature.
Ultimately, I think the problem most likely centers on the fact that using a 60 Hz sine wave as a carrier and superimposing higher frequency data packets on it to transfer information around your home's wiring system is susceptible to a variety of interferences. In a perfect world, the Powerline technology should work and does for most people. However, the uniqueness of our home's wiring and the host of AC power consumers we plug into it is fraught with potential problems.
The power grid was never meant to be used for digital networking as it is a harsh environment for data packets to exist in. Powerline adapters have been designed with all sorts of error correction and retransmission of packets protocols to counteract that environment. Even with those enhancements, they are not going to be able to counteract all the problems inherent to digital communications on a power grid.
First and foremost, every AC powered device that turns on and off creates a voltage dip or surge and while this can be a problem, this occasional disruption is usually handled by the Powerline adapters with packet retransmission or error correction. It's the other things on our electrical system that create a constant stream of high frequency noise that can give Powerline adapters fits. Just off the top of my head: refrigerator compressor motors, vacuum cleaners, hair dryers, washers and dryers, furnaces and air conditioners to name just a few. Even compact florescent lamps can create noise on a home's electrical system. Such devices' noise patterns can destructively interfere with one or multiple channels' worth of powerline networking data and overcome any sort of error correction or packet retransmission.
Next is the issue of networking signal attenuation, which is first and foremost caused by old or otherwise low-quality electrical wiring and the lack of proper grounding (like my house).
Finally, in addition to potential problems of data packets transitioning across 120 VAC phases as I previously mentioned even something as simple as one Powerline adapter having to talk to another adapter on a different circuit breaker can cause packet corruption. In fact, I've read that having a GFCI outlet on the same circuit breaker wiring spur as a Powerline adapter can cause problems even if the adapter isn't plugged into the GFCI.
Add all this to a Microcell that most likely wasn't designed to deal with all this and you can have problems. AT&T should reconsider their blanket recommendation to use Powerline adapters in the Microcell User Guide or at least include warnings about the potential issues I've listed above. This could save a lot of troubleshooting headaches and needless returns of Mcells as was my case.
07-23-2013 11:15 AM
Excellent summary! I'm only alotted about 15 minutes I think to discuss my list of questions but I will certainly make it a point to get to the PowerLine Adapter issue. I already have a feeling on how this is going to go but hopefully I'll be pleasantly surprised.
I really feel that AT&T needs to seriously review the MicroCell and decide on where they want to, or need to, go with the device. This was developed years ago, and technology along with home networks has dramatically changed in that time so AT&T needs to step up their game with the MicroCell. In fact, that's question # 6 on my list (along with HD Voice, 4G/LTE, and 8 other questions). I hope I'm allowed to report back what is discussed.
07-23-2013 12:35 PM
I think one of the biggest improvements to the Microcell would be to eliminate the necessity of the hard-wire (or Powerline) connection to a router. I don't see why it couldn't be wireless. That is essentially what I'm doing right now by plugging the Mcell into my repeater which then wirelessly connects to my router. Put it all in one device.
Removing this tether would solve GPS reception problems due to limited Mcell placement opportunities near a router or having to add an external GPS antenna. It would also eliminate the use of Powerline adapters or messy runs of Ethernet cabling.
Certainly the adaptation of 4G/LTE into the Microcell would be nice but if I'm in my house, I'll be connecting my iPhone to WiFi if I'm doing any heavy lifting of data, so I don't see it as being as high a priority as a Mcell having wireless capability.
One can list many other improvements like reliability, univeral plug and play and so on but those go without saying.
07-23-2013 12:43 PM
- edited 07-25-2013 9:53 AM
The call was.... interesting. There were two folks on the call who were from the MicroCell divison (senior product/marketing development, something like that), but they hadn't had a chance to look over and respond to my list of questions that was submitted to them via the forum admin that I work with. My feeling is that they are still formulating a reponse to my questions because some of them were very specific. We only had about 15 minutes to discuss the MicroCell and then it moved onto upcoming product releases for U-Verse, etc. They are supposed to get back to me so we'll see how that works out.
They did seem reluctant to recommend the use of PowerLine Adapters (even though the original documentation I believe mentioned that you could use them) because the in-home wiring can be too variable unless you have a way of testing the lines. Using a PowerLine Adapter on the same circuit that say your refrigerator is on, wouldn't be a good idea. I told them that if that's the case , then they should remove that from the product literature and they seemed to think that might be a good idea.
The new (at least to me) product literature seems to have a little more information under Key Features, How to Buy, and Requirements but I think it's basically the same. What they presented was marketing stuff without any meat to it, but I think that was more for the other participants beause they don't know a lot about the MicroCell like I don't know a lot about U-Verse. It was a mixed group of ACEs.
They did say that HD Voice (VoLTE) will not be supported by the MicroCell because the unit is still limited to 3G data speeds.
Free MicroCells was an interesting discussion. Basically, that was a targeted marketing campaign aimed at some users who were known to live in an area of very limited or no coverage. Hence the randomness of who got a free unit. If you lived in an area of known bad coverage, and didn't get an offer of a free one, and had a documented history of poor or no in-home coverage, you may have been able to get a free one as well. But that was on a case-by-case basis if you weren't originally offered one. They do not have any current plans to institute the program again, but that could change.
One of the requirements stated: "The AT&T 3G MicroCell must reside within the AT&T 3G MicroCell coverage area." It doesn't specifically address the tower question (which recently came up in another thread) but I think that means tower coverage. Even if you don't have a mobile signal at all in your home, the unit still needs a tower somewhere to move your calls. That's a key question that I'm waiting to get an answer to.
The machine moves very slowly. I am working on a FAQ that hopefully will include answers to some of my questions as well as setup techniques and tricks that have worked for other users, common trouble-shooting procedures, etc.
07-25-2013 11:03 AM
With regard to free Mcells, I had no documentation of poor cell tower signal strength nor did AT&T indicate that I was in an area of poor coverage, yet I was given a free Mcell. I called ATT and specifically listed the problems I was having and insisted that they provide a Mcell to me at no cost or I would be forced to take my business elsewhere.
They capitulated rather quickly, no doubt considering the fact that I had been a customer for the last 10 years, had purchased many cellphones over that time period, and currently was operating 4 iPhones with data plans and unlimited text messaging under one of their family plans. My monthly AT&T bill is $225. I'm sure they considered the fact that for less than one month's billing, they would keep me as a customer and that resulted in a free Mcell.
I've had similiar experiences with other monthly service providers like Dish and Charter. If you believe that you should be compensated for some problem with their service and approach the provider with a firm position backed by facts, a composed demeanor and the willingness to take your business elsewhere, almost always they will forward you to their customer retention group and you will be made whole.
You also mentioned, "Even if you don't have a mobile signal at all in your home, the unit still needs a tower somewhere to move your calls."
By "the unit", are you referring to the Mcell? My understanding is that no towers are involved and that the Mcell communicates to a security gateway, then through a switching gateway to the carrier's mobile switching center all by using the internet. This essentially replicates the radio network subsystem of cell towers and a radio network controller, which then communicates with the mobile switching center.
Am I missing something here?
07-25-2013 11:44 AM
I just repeated what was told to us in the meeting yesterday. But, as with other things that AT&T has said in the past, you need to take that with a grain of salt. I'm sure there are quite a few folks that got free MicroCells that way but the higher ups aren't aware of it (or want to acknowledge it) and are just repeating company policy. Nothing is quite as it seems with AT&T and the MicroCell.
It has always been my understanding that a local tower was necessary for GPS confirmation of service area, 9-1-1, and calls. The calls were eventually routed from the internet and sent thru a local tower (depending on location, condition, etc). At least that's how it was explained to me way back when, but now I'm not so sure. Hence my question(s) to support. That's one of the items I want to include in the FAQ but need definitive answers. This seems to be an area that AT&T is a bit cagey about. The MicroCell (unit) is not supposed to be VOIP, but......
07-25-2013 5:47 PM
No doubt they aren't going to publicize or acknowledge that they are giving people free Mcells but they will give you one if you squawk loud enough, especially if you tell them you are going to walk. It's simple economics. Someone like me who is paying AT&T $2,700 a year tells them their service sucks in my area and I want a Mcell or I'm gone. I'd pay $200 to keep to keep a cash flow like that going. I'm sure they see it the same way.
I'm not sure why a local tower would be necessary for GPS confirmation. The Mcell has its own GPS antenna so it knows where it is and certainly is transmitting that location information to HQ. That information is compared to the listed account address to make sure the Mcell is where it's suppose to be. The same account address is provided to emergency responders if I call E911. Everything I've read about femtocells says that there is no cell tower in the network path.
Besides compensating for weak cell tower signals, another big reason carriers like femtocells is because they can off-load cell towers in areas where their tower networks are being pushed hard. If the Mcell network path included cell towers then it wouldn't help much.
I'd be curious to know how many Mcells AT&T has on their network these days. I read in an article dated May, 2011 that at that time AT&T had 256,000 cell towers while it had grown its Mcell population to 350,000. That's pretty impressive considering the Mcell was rolled out in April, 2010. No doubt the Mcell population is growing faster than their tower infrastructure. I've also read about rumors where Mcell features would be included in future Uverse boxes, but that might be bogus.
07-25-2013 8:24 PM
I agree with you about getting a free femtocell if one squaks loud enough. Threatening to cancel service works wonders at times. I did the very same when my first MicroCell failed. All I'm saying is that, according to AT&T, the official "giveaway" program has ended, which, btw, started sometime after April 2010 when they were first introduced to the public.
I had some time today so I did some serious digging around to try and get some of the answers to my questions. Specificially the tower "requirement" and GPS. I may have to take a mea culpa on some of my recommendations. Hence the FAQ. I've been able to dig up some interesting info which I'd really like AT&T to confirm so we'll see. The MicroCell may in fact be VOIP
GPS apparently serves a couple of functions besides E911 (which, btw, I'd be very reluctant about pressing 9-1-1 on a cell phone for an emergency in my home). Accurate timing signals for the radio without using sophisticated internal clock hardware is one of them.
I also dug up some interesting info on initial activation and handing off which is two other areas of issues for folks.
All in all it's time for me to update my info, confirm as much as I can with AT&T, and put out a FAQ that is as accurate as can be.
As far as U-Verse goes, there is some talk about making it more compatible with the MicroCell but we'll just have to wait and see I don't have cable or satellite so it's not important to me, but........
07-26-2013 10:48 AM
If there is anything I can do to help you put together a FAQ page (writing, editing, fact finding, et.al....) I'd be happy to assist.
07-26-2013 10:58 AM
You read my mind. As soon as I hear back from AT&T (which could take some time) I'll edit what I have, which is getting to be a long document, and then touch base, either here or by pm. I'm here a lot (obviously) so feel free to contact me.
07-27-2013 9:38 PM