# EM9191 FW Update and Calibration **URL:** \ **Category:** MC/EM Series\ **Tags:** fw-upgrade\ **Created:** [May 11, 2022, 7:59am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986 "2022-05-11T07:59:53Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Felix.Plank](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@Felix.Plank](https://forum.sierrawireless.com/u/Felix.Plank)\ **Post date:** [May 11, 2022, 7:59am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/1 "2022-05-11T07:59:53Z")
Hello together, I updated my EM9191 device from Firmware SWIX55C\_01.07.19.00\_GENERIC\_016.010\_002 to SWIX55C\_03.04.03.00\_GENERIC\_030.012\_000. Before that I was able to establish an TDD (n78) connection towards an AMARI callbox (cellular test device) but not to any FDD band. After the FW-Update an FDD connection could be established but in the end there was no data exchange through a performed iperf run. The formally easily to establish TDD connection was than no longer feasible. Is there a necessity to ajust calibration data with each new firmware, or where can be the root causes of such behavior. Every hint is welcome. 🙂 Thank you all very much in advance. Greetings Felix ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [May 11, 2022, 8:06am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/2 "2022-05-11T08:06:43Z")
have you checked AT!RFCOMBOS? or AT!BAND=? and see if this band is available? ---
**Author:** ![Felix.Plank](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@Felix.Plank](https://forum.sierrawireless.com/u/Felix.Plank)\ **Post date:** [May 11, 2022, 8:30am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/3 "2022-05-11T08:30:43Z")
Hello, the bands are available and the callbox is providing a 5G stand alone network with only one transmitted band (either band n5, n7 or n78). ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [May 11, 2022, 8:37am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/4 "2022-05-11T08:37:29Z")
from product technical specification, n78 should be TDD band Have you tried some newer FW? ---
**Author:** ![Felix.Plank](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@Felix.Plank](https://forum.sierrawireless.com/u/Felix.Plank)\ **Post date:** [May 11, 2022, 9:04am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/5 "2022-05-11T09:04:36Z")
well with the old FW n78 TDD is working properly but with the newest available version on the web resources I can get an connection with band n7 FDD but no actual data traffic. A registration of the modem with band n78 was not possible with the newer FW ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [May 11, 2022, 9:20am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/6 "2022-05-11T09:20:28Z")
you mean you have tried “SWIX55C\_03.09.06.00”? ---
**Author:** ![Felix.Plank](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@Felix.Plank](https://forum.sierrawireless.com/u/Felix.Plank)\ **Post date:** [May 11, 2022, 10:07am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/7 "2022-05-11T10:07:17Z")
Oh, I did not realize that there is already a version 03.09.06. Thanks for the hint. But back to my second question. Is there anything regarding calibration when updating a modem. We got some feedback from a customer that this was sometimes necessary for older modems. Not necessarily from Sierra Wireless but also for other modem suppliers. ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [May 11, 2022, 10:18am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/8 "2022-05-11T10:18:33Z")
AT!BAND=? will show only the bands calibrated. ---
**Author:** ![Felix.Plank](https://avatars.discourse-cdn.com/v4/letter/f/d07c76/32.png) [@Felix.Plank](https://forum.sierrawireless.com/u/Felix.Plank)\ **Post date:** [May 11, 2022, 10:51am UTC](https://forum.sierrawireless.com/t/em9191-fw-update-and-calibration/26986/9 "2022-05-11T10:51:32Z")
ok, thanks for your help 🙂 I think that can help us with our customer communication.