EM7455 does not list Band 30 as valid AT!BAND


#1

I have a Lenovo EM7455 and wanted to do some testing locked on Band 30 (AT&T) as there are towers in the area that support it. However, when going through the process of adding band profiles, I discovered that Band 30 is not on the list, at all. According to all spec sheets I have read, Band 30 is supported on this modem.

At first I tried both of the following firmwares:

AT!ENTERCND="A710"
AT!PRIID?
PRI Part Number: 9905288
Revision: 001.004
Customer: Lenovo-Storm


Carrier PRI: 9999999_9904594_SWI9X30C_02.24.03.00_00_ATT_002.023_000
Carrier PRI: 9999999_9904609_SWI9X30C_02.08.02.00_00_GENERIC_002.007_000

OK
AT!GOBIIMPREF?
!GOBIIMPREF: 
 preferred fw version:    02.24.03.00
 preferred carrier name:  ATT
 preferred config name:   ATT_002.023_000
 current fw version:      02.24.03.00
 current carrier name:    ATT
 current config name:     ATT_002.023_000

OK

I’m using the following to cycle firmwares:

AT!ENTERCND="A710"
AT!IMPREF="GENERIC"
AT!RESET

On both the above ATT and GENERIC firmwares, band 30 does not show when I run AT!BAND=?

AT!ENTERCND="A710"
AT!BAND=?
Index, Name,                        GW Band Mask     L Band Mask      TDS Band Mask
00, All bands                     0002000007C00000 00000100030818DF 0000000000000000
01, Europe 3G                     0002000000400000 0000000000000000 0000000000000000
02, North America 3G              0000000004800000 0000000000000000 0000000000000000
06, Europe                        0002000000400000 00000000000800C5 0000000000000000
07, North America                 0000000004800000 000000000300185A 0000000000000000
08, WCDMA ALL                     0002000007C00000 0000000000000000 0000000000000000
09, LTE ALL                       0000000000000000 00000100030818DF 0000000000000000

                                                   0000010000000000 - B41    
                                                   0000000002000000 - B26    
                                                   0000000001000000 - B25    
                                                   0000000000080000 - B20    
                                                   0000000000001000 - B13    
                                                   0000000000000800 - B12    
                                                   0000000000000080 - B8     
                                                   0000000000000040 - B7     
                                                   0000000000000010 - B5     
                                                   0000000000000008 - B4     
                                                   0000000000000004 - B3     
                                                   0000000000000002 - B2     
                                                   0000000000000001 - B1     
                                  0002000000000000 - B8  (900)
                                  0000000004000000 - B5  (850)
                                  0000000002000000 - B4 (1700)
                                  0000000001000000 - B3 (1700)
                                  0000000000800000 - B2 (1900)
                                  0000000000400000 - B1 (2100)

OK

So, I tried flashing the latest firmwares for both GENERIC and ATT:

AT!PRIID?
PRI Part Number: 9905288
Revision: 001.004
Customer: Lenovo-Storm

Carrier PRI: 9999999_9904594_SWI9X30C_02.24.05.06_00_ATT_002.027_000
Carrier PRI: 9999999_9904609_SWI9X30C_02.24.05.06_00_GENERIC_002.026_000

OK

Once again, swapping between both images, still no Band 30.

AT!GOBIIMPREF?
!GOBIIMPREF: 
 preferred fw version:    02.24.05.06
 preferred carrier name:  GENERIC
 preferred config name:   GENERIC_002.026_000
 current fw version:      02.24.05.06
 current carrier name:    GENERIC
 current config name:     GENERIC_002.026_000

OK

I found reference here of someone with the Verizon firmware showing Band 30, so I tried using the code from that to set a custom band anyways:

AT!ENTERCND="A710"
AT!BAND=10,"B30 (2300)",0,0000000020000000
OK
AT!BAND=10
ERROR

I didnt think that would work, and the custom Band 10 doesnt show on AT!BAND=?

So, I flashed the Verizon firmware:

AT!IMPREF?
!IMPREF: 
 preferred fw version:    02.24.05.06
 preferred carrier name:  VERIZON
 preferred config name:   VERIZON_002.034_000
 current fw version:      02.24.05.06
 current carrier name:    VERIZON
 current config name:     VERIZON_002.034_000

OK

The results were not helpful.

AT!BAND=?
Index, Name,                        GW Band Mask     L Band Mask      TDS Band Mask
00, All bands                     0002000007C00000 000000000000100A 0000000000000000
01, Europe 3G                     0002000000400000 0000000000000000 0000000000000000
02, North America 3G              0000000004800000 0000000000000000 0000000000000000
06, Europe                        0002000000400000 0000000000000000 0000000000000000
07, North America                 0000000004800000 000000000000100A 0000000000000000
08, WCDMA ALL                     0002000007C00000 0000000000000000 0000000000000000
09, LTE ALL                       0000000000000000 000000000000100A 0000000000000000

                                                   0000000000001000 - B13    
                                                   0000000000000008 - B4     
                                                   0000000000000002 - B2     
                                  0002000000000000 - B8  (900)
                                  0000000004000000 - B5  (850)
                                  0000000002000000 - B4 (1700)
                                  0000000001000000 - B3 (1700)
                                  0000000000800000 - B2 (1900)
                                  0000000000400000 - B1 (2100)

OK

It looks like the NVU sets available bands, looking at the different NVUs, AT&T and Generic are almost identical except for the signing of the NVU on the AT&T one and MCC selection. The Verizon NVU contains all sorts of extra settings, that dont look much like band selection.

Any ideas of getting Band 30 access on this modem, or is that just not a thing?


#2

Hi danielwood,

The band setting depends on product/SKU itself, loading different carrier firmware has no effect on it.

Are you able to check with Lenovo support for list of RF band supported for your Lenovo laptop?

Thx


#3

Yes, the Lenovo EM7455 supports Band 30 on both versions sold by Lenovo:

Sierra Wireless AirPrime® EM7455 module (4XC0L59128):
+ Intended for: ThinkPad T460, T460s, T460p, T560, X260, X1 Carbon, L460, P50, P70
+ Specs: https://download.lenovo.com/pccbbs/options_iso/tp_em7455_4gltem_4xc0l59128.pdf

Sierra Wireless AirPrime® EM7455 module (4XC0M95181):
+ Intend for: ThinkPad L470, L570, P51, P51s, P70, P71, T470, T470p, T470s, T570, TP25, X270
+ Specs: https://download.lenovo.com/pccbbs/options_iso/tp_em7455_4g_lte_4xc0m95181.pdf

That said, a Sierra Wireless employee may need to chime in here, because further reading has lead me to this gem within the AirPrime EM7455 Product Technical Specification PDF on Page 62:

*Important: The FCC and IC have a strict EIRP limit in Band 30 for mobile and portable stations in order to
protect adjacent satellite radio, aeronautical mobile telemetry, and deep space network operations. Mobile
and portable stations must not have antenna gain exceeding 1 dBi in Band 30. Additionally, both the FCC
and IC prohibit the use of external vehicle-mounted antennas for mobile and portable stations in this band.

Fixed stations may use antennas with higher gain in Band 30 due to relaxed EIRP limits. EM7455 modules
used as fixed subscriber stations in Canada or fixed customer premises equipment (CPE) stations in the
United States may have an antenna gain up to 10 dBi in Band 30, however, the use of outdoor antennas or
outdoor station installations are prohibited except if professionally installed in locations that are at least
20 meters from roadways or in locations where it can be shown that the ground power level of -44 dBm per
5 MHz in the bands 2305–2315 MHz and 2350–2360 MHz or -55 dBm per 5 MHz in the bands 2315–
2320 MHz and 2345–2350 MHz will not be exceeded at the nearest roadway. For the purposes of this notice,
a roadway includes a highway, street, avenue, parkway, driveway, square, place, bridge, viaduct or trestle,
any part of which is intended for use by the general public for the passage of vehicles.

Mobile carriers often have limits on total radiated power (TRP), which requires an efficient antenna. The end
product with an embedded module must output sufficient power to meet the TRP requirement but not too
much to exceed FCC/IC's EIRP limit. If you need assistance in meeting this requirement, please contact
Sierra Wireless.

That sounds a lot like Band 30 is disabled without some kind of validation check that the antenna gain is 1dB or less. I’m guessing older firmwares did not have this check as the FCC had not yet mandated this requirement.


#4

My Dell DW5811e arrived today. Now running the same firmware and NVU, it has Band 29 and Band 30.

It looks like the Lenovo em7455 (Specifically the 4XC0L59128 / 00JT542) does not support bands 29 or 30. The spec sheets from Lenovo are a lie. I would stay away from the Lenovo card unless you are specifically installing it in a Lenovo *70 series. In that case, you dont want the 4XC0L59128 / 00JT542, you want the 4XC0M95181 / 01AX746.