Sierra Aircard 881 or 881U?

htneighbors

Unbelievably Blessed!
EVDOalex,

How can I tell which one I have? Does the 'U' mean it is USB connect? If so, that is the one I have. Service through AT&T.

Also...how effective are the external antennas? I need a signal boost! :( My card works great most of the time, but when receiving larger emails with attached files, usually 2-3MB or larger, it usually will not download them. I use this on a jobsite location and need to receive pdf blueprints from the engineers. It is 3G, so when is populated areas with 3G service, it works like a dream. But I am currently stuck in Nowhere, Wyoming and use my aircard almost exclusively! Every now and then, the wifi signal from the RV park, where I'm living, has a decent signal to reach my RV. I have driven closer to her office to use a better signal and download larger files. (Got a booster antenna for her wifi, too! :) ) Most of the time - right now included - I have 4 bars showing on my indicator. It is showing a speed of 3.6Mbps.

Also, a co-worker on this job has service through Alltel. He has some sort of Booster mounted behind the dash in his pick-up, with a switch installed on his dash and an antenna about 4 inches tall on the top. This assists in boosting his cell phone and aircard signal. Is there something available that will work with the Sierra card I have?

Thanks!
 

AlexSian

Mobile Broadband Consultant
Most of the time - right now included - I have 4 bars showing on my indicator. It is showing a speed of 3.6Mbps
to me, this means that signal is not your problem and antenna and/or booster/amp are not going to do much, if anything.

try reading this article, to see if you can figure out your "RSSI", thats a signal value represented as a negative number, and is a better way to judge signal than "bars" are:

http://www.EVDOinfo.com/RSSI

if you take the time to do the testing and provide answers to questions at bottom of article, it should be easier to tell you if antenna/amp will help.

-- alex

PS: if it connects via USB port, then it is 881U.
 

htneighbors

Unbelievably Blessed!
RSSI is currently at -56 dBm. I have seen it -80 and up to -30. Regardless of where it has been - large files will usually not load. If they do, it takes up to an hour - and the largest file I have ever been able to upload was only about 5 megs in size. Co-workers here at same jobsite with me have no problems.
 

AlexSian

Mobile Broadband Consultant
RSSI is currently at -56 dBm. I have seen it -80 and up to -30. Regardless of where it has been - large files will usually not load.
the closer to zero the better the signal.

-80 is already "good"
-56 is great. rare.
-30 is amazing. almost never happens.

based on these numbers you are getting, i'd have to say signal is not your issue and that an antenna or booster/amp will do nothing for you.

maybe your 881u is defective?

process of elimination time. try your 881u on someone else's computer.

if problem moves with device, i'd say its device.

if a coworker has an 881u that is working great for them, try it on your computer.

if you STILL don't see good results, problem is likely to be YOUR computer.

-- alex
 

Pulltab

Well-known member
I have the 881 which is the pcmcia version, I have yet to be in a reasonable location to get a great signal :( Highest speed I have ever gotten was about 500 down. Its odd that if I check the upload with using the microsoft controlling the card I may get like 80k upload, yet if I run the ATT software and let it control the card I may be 400k upload. Not sure I am seeing what is going on there, it only affects the upload and does nothing for the download.

the u does mean its the usb version
 
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