[Lenovo Vibe Shot Questions & Answers] Ineedabitofhelp:
In short :

Lenovo Vibe Shot Z90-7

Current rom : S226 ( android 5.1) Pre-rooted

I need help setting band priority in Phone settings. I would like my phone to constantly look for LTE signal , only connect to 3g in brief periods when not finding LTE and reconnect to LTE as soon as found again.

The problem :

I have signal 2-3-sometimes 4 bars of LTE (2600mhz) however. once it drops for a second or two to Hspa it stays there and doesnt go back to lte. Resetting the modem to regain Lte doesnt always work, sometimes whole phone reboot is necessary. And since my carrier is LTE only (they rent 3g from other T-mobile) They dont like if im on 3g to much. And personally since i pay for 4g and have the signal. I would like to have it.

How i Got here :

I have started my long and unfruitful search after seeing that my internet kept dropping to 3g and staying there (untill i resetted modem)

Unknowingly i followed a guid, entered *#*#INFO#*#* > phone settings > set my phone to USA band. This kinda broke my phone since I live in Europe

Flashed Rom with Root (even bricked and unbricked it twice, but thats another story)

Then after long search i found another guide found here followed the guide and set my band to 46 (aka use all pretty sure thats also what it was like before) And now im pretty much back to where i started. With ofc lots of new learned information. But the same problem that i started with

So my choices are :

Enable all bands and let phone roam on 3g

Or what i did now : with adb shell and AT$QCBANDPREF command : enable all but channel : 9 (gsm 900) , 32 (lte 800) just in case it does work? , 33 (lte 2600) , 38 (wlan 2400)) So now my phone connects to LTE 90% of the time. But certain parts of the city i have no internet and ofc if i ever leave the city chance are high i wont have it there either. Neither are very good choices in my book. But for now i have the least worse one selected :/

*I tried to find Msl code to try to unlock lte bands with some guide. But no. As i understand correctly since its a snapdragon no msl and have to enable via adb fastboot?

*Tried to unlock bands guide found here But since phone doesn't have official root. Just pre-rooted (and cant find any real root) I cannot install the patch and thus QXDM /NV browser wont recognize my phone (everything stays greyed out) /

*And unfortunately the simple solution in androids settings - > mobiele networks - preffered network type : my only option with Lte is : LTE/WCDMA/GSM auto. Not that this matters since i also tried to downgrade to previous rom. and by miracle in previous rom i did have the option that stated 4g preferred. However, it still went back to hspa and stayed there. So no help there either

Im hoping im just thinking to deep and there is a simpler option. At the moment im thinking that maybe its because of the AT$QCBANDPREF command ? That i set the preferred network and soon as it finds one of the preferred network connections it connects and stays with it. (and thus not dropping 3g)

Edit : Build Prop : Im thinking there could be a good chance i can alter/add an option in my build prop to always make it look for a certain lte band? But im drawing a blank what that option would be.

# begin build properties
# autogenerated by buildinfo.sh
ro.build.id=LMY47O
ro.build.display.id=Z90a40_S226_151022_ROW
ro.build.version.incremental=Z90a40_S226_151022_ROW
ro.build.version.sdk=22
ro.build.version.codename=REL
ro.build.version.all_codenames=REL
ro.build.version.release=5.1
ro.build.version.security_patch=2015-11-01
ro.build.version.base_os=
ro.build.date=Thu Oct 22 17:59:40 CST 2015
ro.build.date.utc=1445507980
ro.build.type=user
ro.build.user=buildslave
ro.build.host=njbs13
ro.build.tags=release-keys
ro.build.flavor=zoom_row-user
ro.product.model=Lenovo Z90a40
ro.product.brand=Lenovo
ro.product.name=zoom_row
ro.product.device=zoom_row
ro.product.board=msm8916
# ro.product.cpu.abi and ro.product.cpu.abi2 are obsolete,
# use ro.product.cpu.abilist instead.
ro.product.cpu.abi=arm64-v8a
ro.product.cpu.abilist=arm64-v8a,armeabi-v7a,armeabi
ro.product.cpu.abilist32=armeabi-v7a,armeabi
ro.product.cpu.abilist64=arm64-v8a
ro.product.manufacturer=LENOVO
ro.wifi.channels=
ro.board.platform=msm8916
# ro.build.product is obsolete; use ro.product.device
ro.build.product=zoom_row
# Do not try to parse description, fingerprint, or thumbprint
ro.build.description=zoom_row-user 5.1 LMY47O Z90a40_S226_151022_ROW release-keys
ro.build.fingerprint=Lenovo/zoom_row/zoom_row:5.1/LMY47O/Z90a40_S226_151022_ROW:user/release-keys
ro.build.characteristics=default
ro.lenovo.series=VIBE Shot
ro.lenovo.vibeui.apps=1f4f94a
ro.lenovo.vibeui.patch_mtk=
ro.lenovo.vibeui.patch_qcom=
ro.lenovo.vibeui.patch_intel=
ro.lenovo.vibeui.resources=6e3f17e
ro.lenovo.vibeui.components=a2c0c26
ro.lenovo.vibeui.tools=7fe0357
ro.lenovo.lvp.version=V2.6.0.0_1508211147_A1f4f94aR6e3f17eCa2c0c26T7fe0357P840b86d
persist.lenovo.feedback=false
# end build properties
#
# from device/lenovo/zoom_row/system.prop
#
#
# system.prop for msm8916
#

rild.libpath=/vendor/lib64/libril-qc-qmi-1.so
rild.libargs=-d /dev/smd0
persist.rild.nitz_plmn=
persist.rild.nitz_long_ons_0=
persist.rild.nitz_long_ons_1=
persist.rild.nitz_long_ons_2=
persist.rild.nitz_long_ons_3=
persist.rild.nitz_short_ons_0=
persist.rild.nitz_short_ons_1=
persist.rild.nitz_short_ons_2=
persist.rild.nitz_short_ons_3=
ril.subscription.types=NV,RUIM
DEVICE_PROVISIONED=1
# Start in cdma mode
ro.telephony.default_network=9,1

debug.sf.hw=0
debug.egl.hw=0
persist.hwc.mdpcomp.enable=true
debug.mdpcomp.logs=0
dalvik.vm.heapsize=36m
dev.pm.dyn_samplingrate=1
persist.demo.hdmirotationlock=false

#ro.hdmi.enable=true
#tunnel.decode=true
#tunnel.audiovideo.decode=true
#lpa.decode=false
#lpa.use-stagefright=true
#persist.speaker.prot.enable=false

#
# system props for the cne module
#
#persist.cne.feature=1

#system props for the MM modules
media.stagefright.enable-player=true
media.stagefright.enable-http=true
media.stagefright.enable-aac=true
media.stagefright.enable-qcp=true
media.stagefright.enable-fma2dp=true
media.stagefright.enable-scan=true
media.swhevccodectype=0
mm.enable.smoothstreaming=true
mmp.enable.3g2=true
media.aac_51_output_enabled=true

#codecs:DivxHD Divx FLAC QCP MP2TS 3G2 DTS AVI AC3 AAC
mm.enable.qcom_parser=3314275

# Default to AwesomePlayer
media.stagefright.use-awesome=true

#
# system props for the data modules
#
ro.use_data_netmgrd=true
persist.data.netmgrd.qos.enable=true

#system props for time-services
persist.timed.enable=true

#
# system prop for opengles version
#
# 131072 is decimal for 0x30000 to report version 3
ro.opengles.version=196608

# System property for cabl
ro.qualcomm.cabl=0

#
# System props for telephony
# System prop to turn on CdmaLTEPhone always
telephony.lteOnCdmaDevice=1

#
# System props for bluetooh
# System prop to turn on hfp client
bluetooth.hfp.client=1

#Simulate sdcard on /data/media
#
persist.fuse_sdcard=true

#
#snapdragon value add features
#
ro.qc.sdk.audio.ssr=false
##fluencetype can be "fluence" or "fluencepro" or "none"
ro.qc.sdk.audio.fluencetype=fluence
persist.audio.fluence.voicecall=true
persist.audio.fluence.voicerec=false
persist.audio.fluence.speaker=false
#Set for msm8916
tunnel.audio.encode = false
#Buffer size in kbytes for compress offload playback
audio.offload.buffer.size.kb=32
#use VERY_HIGH_QUALITY for audio resampler
af.resampler.quality=4
#Enable offload audio video playback by default
av.offload.enable=false
#enable voice path for PCM VoIP by default
use.voice.path.for.pcm.voip=true

#System property for FM transmitter
ro.fm.transmitter=false
#enable dsp gapless mode by default
audio.offload.gapless.enabled=true
#Audio voice concurrency related flags
voice.playback.conc.disabled=false
voice.record.conc.disabled=false
voice.voip.conc.disabled=false
#property to enable user to access Google WFD settings
persist.debug.wfd.enable=1
#property to enable VDS WFD solution
persist.hwc.enable_vds=1

#property to enable narrow search range for video encoding
vidc.enc.narrow.searchrange=1

ro.qcom.ad.sensortype=2

ro.qcom.ad=1

ro.lenovo.owner_sdcard_support=1

#enable atfwd
persist.radio.atfwd.start=true

# Enable silent PIN1
persist.radio.sap_silent_pin=1

#
# ADDITIONAL_BUILD_PROPERTIES
#
persist.sys.lenovo.shutdown=TRUE
persist.sys.lenovo.log.limit=4000
persist.sys.lenovo.log.disk=/storage/sdcard0
persist.sys.lenovo.log.system=TRUE
persist.sys.lenovo.log.kernel=TRUE
persist.sys.lenovo.log.other=TRUE
persist.sys.lenovo.log=FALSE
persist.sys.dloadmode.config=0
persist.sys.lenovo.Acrash.cnt=0
persist.sys.lenovo.Kcrash.cnt=0
persist.sys.lenovo.crash.path=/data/local/log/lastlog
persist.sys.lenovo.crash.out=/storage/sdcard0/log_out
ro.config.notification_sound=Notice.ogg
ro.config.alarm_alert=New_Morning.ogg
ro.config.ringtone=Fantastic_Clang.ogg
ro.config.ringtone_2=Fantastic_Clang.ogg
ro.config.sms_notifi_sound=Curiosity.ogg
ro.config.sms_notifi_sound_2=Curiosity.ogg
dalvik.vm.heapgrowthlimit=256m
keyguard.no_require_sim=true
ro.com.android.dataroaming=true
ro.com.android.dateformat=MM-dd-yyyy
ro.carrier=unknown
sys.lenovo.romui.version.sdk=3
ro.ril.hsxpa=1
ro.ril.gprsclass=10
ro.adb.qemud=1
ro.vendor.extension_library=libqti-perfd-client.so
persist.radio.apm_sim_not_pwdn=1
persist.radio.sib16_support=1
dalvik.vm.heapstartsize=12m
dalvik.vm.heapsize=512m
dalvik.vm.heaptargetutilization=0.75
dalvik.vm.heapminfree=16m
dalvik.vm.heapmaxfree=32m
ro.lenovo.device=phone
ro.lenovo.platform=qualcomm
ro.com.google.clientidbase=android-lenovo
ro.lenovo.audioparaver=ZOOM_Audio_Parameter_ROW_PVT_20150630
ro.frp.pst=/dev/block/bootdevice/by-name/config
persist.cne.feature=0
ro.telephony.default_network=22,1
persist.radio.multisim.config=dsds
ro.product.ota.model=LenovoZ90a40_ROW
ro.lenovo.easyimage.enable=yes
ro.lenovo.systemverify.enable=yes
ro.product.sw.internal.version=Z90a40_USR_S226_1510221726_Q2020131.4_ROW
ro.lenovo.support.ipdial=true
ro.lenovo.region=row
ro.lenovo.sim=dsds
ro.lenovo.operator=open
ro.lenovo.bqb=pass
ro.lenovo.wificert=no
ro.lenovo.adb=apkctl,speedup
ro.lenovo.signalbars=four
ro.lenovo.videocall=false
ro.lenovo.vibeuistyle=true
persist.backgrounddata.enable=false
persist.lenovo.ltetype=CSFB
persist.log.debug=0
persist.sys.timezone=Asia/Shanghai
ro.product.locale.language=en
ro.product.locale.region=US
ro.sf.lcd_density=480
persist.radio.rat_on=combine
persist.radio.ruimenabled=true
persist.sys.ruimenabled=true
persist.radio.primarycard=true
persist.env.fastdorm.enabled=true
persist.sim.simlock=false
persist.sim.simunlock=false
ro.lenovopctl=1
ro.setupwizard.mode=OPTIONAL
ro.com.google.gmsversion=5.1_r1
ro.com.google.clientidbase.ms=android-lenovo
ro.com.google.clientidbase.am=android-lenovo
ro.com.google.clientidbase.gmm=android-lenovo
ro.com.google.clientidbase.yt=android-lenovo
drm.service.enabled=true
ro.com.widevine.cachesize=16777216
persist.sys.dalvik.vm.lib.2=libart.so
dalvik.vm.isa.arm64.features=div
dalvik.vm.isa.arm.features=div
net.bt.name=Android
dalvik.vm.stack-trace-file=/data/anr/traces.txt
persist.gps.qc_nlp_in_use=1
persist.loc.nlp_name=com.qualcomm.location
ro.gps.agps_provider=1
ro.pip.gated=0

What i would like in short

I hope it can be done with this AT$QC command? new to this, but i have adb shell and su acces and minor understanding of what i did so far. Basicly i just want to tell my phone :

preferend band = 2600 // If not found then (and only then) go to other band (900mhz 3g) And ofc preferred band meaning it will also switch back once signal is re-established.

Thanks for reading and hoping someone will be able to help me out. (p.s sorry if im in wrong section, there is no lenovo vibe z90 thread, only vibe p1 and wasnt sure to post there, and all other z90 treads are mostly about roms :/ )