Category: Wireless

Network Signal Guru on the Nexus 6P – Archived – Version 1

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Please Note: This is not the most current version of this guide.  Please see this page for the most current version.  This is Version 1 of the guide.

Network Signal Guru is a new app that gives TONS of information on the cellular networks that you are connected to.  Unfortunately, the Nexus 6P by default is lacking one of the most important functions of the app: Band Locking.  Huawei crippled this feature from the factory.

Band Locking enables you to allow your phone to only search for service on the bands that you specify.  This is important if you are trying to identify specific coverage in specific locations, or do other testing with your phone.  Additionally, if you find that one band is severely congested, you can force your phone to stay on a different particular band.

Below is a simple guide on how to get this capability.  This assumes you already have a working Nexus 6P with TWRP Recovery already installed (software version not relevant), and also assumes a rather decent knowledge on flashing / modifying your phone.  This also assumes that you have ADB and Fastboot already installed on your computer.  You will need to wipe your entire device, so make a complete backup before starting.

  • Download the NBD90X image for the Nexus 6P from here.
  • Once downloaded, extract the ZIP file to a location you remember.
  • Reboot your device into Recovery Mode, and wipe the entire system.  You want a completely blank and wiped device.
  • Reboot the device into the Bootloader.
  • Navigate to the directory you just extracted the ZIP to, and execute the flash_all.sh script from a shell on your computer.  This will install Android Nougat 7.0, build NBD90X onto your phone.
  • Once the installation has completed, allow the phone to reboot.  At the initial setup screen, reboot into the Bootloader again.
  • Download TWRP Recovery version 3.0.2-2 from here.
  • Place the TWRP recovery image in the same directory as your extracted image above.
  • At the Bootloader, issue the following commands:
    fastboot flash recovery twrp-3.0.2-2-angler.img
    fastboot reboot
  • Allow the phone to reboot to the initial setup screen once again.  Once there, reboot the phone back into the Bootloader.
  • Download the Nexus 6P Engineering Radio from here.
  • Extract the radio into the same directory that you have been using.
  • At the Bootloader, issue the commands:
    fastboot flash radio radio.img
    fastboot reboot
  • Allow the phone to reboot to the initial setup screen once again.  Once there, reboot the phone back into the Bootloader.
  • Select Boot Recovery from the Bootloader screen to boot into TWRP Recovery.
  • Download SuperSU from your favorite source.
  • Copy the SuperSU ZIP to a flash drive, and insert the flash drive into your Nexus 6P (via USB-C to USB adapter).
  • Install the SuperSU ZIP from the flash drive.
  • Reboot the phone.
  • Continue through the setup process for the first time.  Ensure you set the phone up completely from scratch, and do not recover anything from a previous install (either through TWRP Recovery or through the stock Android setup tool).
  • Sign into the Google Play Store, and download Network Signal Guru.
  • Start Network Signal Guru, and grant it Root permissions.
  • You’re done!  If you have completed all of the steps correctly, you should now see the Band Locking option enabled in the Magic Wand menu.  Additionally, RAT Locking will also work natively within the app, and will not send you to the phone’s stock internal menu.

You may not have to be quite as thorough as I was to achieve the same success, so feel free to experiment.  However, I do know that when I was on different Nougat build, no combination of trying to flash the radio to my then-current setup would work.  The above steps are the only way I could reliably replicate a working setup.

Now, I have not been able to extensively test this radio in the real world at this time, nor am I where I can test the features of band locking in a real-world environment, as I am out of the country at the moment.  As soon as I am able, I will update this page with my results.  Until then, anyone that has feedback is requested to post in the comments below.

I am not responsible for anything that happens as a result of the instructions on this page.  Proceed at your own risk.

Network Signal Guru on the Nexus 6P

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Network Signal Guru is a new app that gives TONS of information on the cellular networks that you are connected to.  Unfortunately, the Nexus 6P by default is lacking one of the most important functions of the app: Band Locking.  Huawei crippled this feature from the factory.

Band Locking enables you to allow your phone to only search for service on the bands that you specify.  This is important if you are trying to identify specific coverage in specific locations, or do other testing with your phone.  Additionally, if you find that one band is severely congested, you can force your phone to stay on a different particular band.

Below is a simple guide on how to get this capability.  This assumes you already have a working Nexus 6P with TWRP Recovery already installed (software version not relevant), and also assumes a rather decent knowledge on flashing / modifying your phone.  This also assumes that you have ADB and Fastboot already installed on your computer.  You will need to wipe your entire device, so make a complete backup before starting.

  • Download the NMF26F image for the Nexus 6P from here.
  • Once downloaded, extract the ZIP file to a location you remember.
  • Reboot your device into Recovery Mode, and wipe the entire system.  You want a completely blank and wiped device.
  • Reboot the device into the Bootloader.
  • Navigate to the directory you just extracted the ZIP to, and execute the flash_all.sh script from a shell on your computer.  This will install Android Nougat 7.1.1, build NMF26F onto your phone.
  • Once the installation has completed, allow the phone to reboot.  At the initial setup screen, reboot into the Bootloader again.
  • Download the Nexus 6P Engineering Radio from here.
  • Extract the radio into the same directory that you have been using.
  • At the Bootloader, issue the commands:
    fastboot flash radio radio.img
    fastboot reboot
  • Allow the phone to reboot to the initial setup screen once again.  Once there, reboot the phone back into the Bootloader.
  • Download TWRP Recovery version 3.0.3-0 from here.
  • Place the TWRP recovery image in the same directory as your extracted image above.
  • At the Bootloader, issue the following commands:
    fastboot flash recovery twrp-3.0.3-0-angler.img
    fastboot reboot
  • Allow the phone to reboot to the initial setup screen once again.  Once there, reboot the phone back into the Bootloader.
  • Select Recovery Mode from the Bootloader screen to boot into TWRP Recovery.
  • Download SuperSU from here.
  • Copy the SuperSU ZIP to a flash drive, and insert the flash drive into your Nexus 6P (via USB-C to USB adapter).
  • Install the SuperSU ZIP from the flash drive.
  • Reboot the phone.
  • Continue through the setup process for the first time.  Ensure you set the phone up completely from scratch, and do not recover anything from a previous install (either through TWRP Recovery or through the stock Android setup tool).
  • Sign into the Google Play Store, and download Network Signal Guru.
  • Start Network Signal Guru, and grant it Root permissions.
  • You’re done!  If you have completed all of the steps correctly, you should now see the Band Locking option enabled in the Magic Wand menu.  Additionally, RAT Locking will also work natively within the app, and will not send you to the phone’s stock internal menu.

You may not have to be quite as thorough as I was to achieve the same success, so feel free to experiment.  However, I do know that when I was on different Nougat build, no combination of trying to flash the radio to my then-current setup would work.  The above steps are the only way I could reliably replicate a working setup.

Now, I have not been able to extensively test this radio in the real world at this time, nor am I where I can test the features of band locking in a real-world environment, as I am out of the country at the moment.  As soon as I am able, I will update this page with my results.  Until then, anyone that has feedback is requested to post in the comments below.

EDIT: It has been reported that if you have a phone on a previous version, and take the OTA update to 7.1.1 (Build NPF10C), that you can start at the sixth step above, skipping a full wipe and flash of the OS.

For the original version of this guide, please proceed here.

I am not responsible for anything that happens as a result of the instructions on this page.  Proceed at your own risk.

Project Fi Carrier Switching

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Forcing Carrier Switching:

The phone can be forced to search for service on any of the three by inputting the following dialer codes:

*#*#34777#*#* – Force Sprint
*#*#34866#*#* – Force T-Mobile
*#*#34326#*#* – Force US Cellular
*#*#346398#*#* – Force Next Carrier
*#*#342886#*#* – Resume Automatic Switching

No matter which carrier you force the phone to switch to, the phone will resume automatically switching after two hours.  At this time, this cannot be stopped.

Additionally, these dialer codes may come in handy:

*#*#344636#*#* – Current Network Info
*#*#34963#*#* – Repair a Bad Activation
*#*#4636#*#* – Launch Phone Test Menu

Dialer Code Apps:

FiSwitch is primarily meant to act as an easy way to input dialer codes.  If you are stock, the code will be copied to the clipboard, it will open the Dialer, and if you enable certain settings, be automatically pasted into the Dialer.  All you have to do is hit dial  If you are rooted, the code will be automatically executed upon pressing the button in the app.  The app also comes with a handy widget that presents the three carriers to quickly switch between them.

Signal Spy provides the same dialer code input into the Dialer, although having root will not assist you here; you still have to hit dial.  However, the app displays much more information about the network you are connected to, as well as a network history.

I personally have both.  I use the FiSwitch widget for quickly switching carriers from the Home Screen (while rooted), as well as determining which carrier I am on at a glance.  I use Signal Spy to determine which network and band I am on, as more detailed information is displayed within the Signal Spy app as opposed to just the carrier name on the FiSwitch widget.

Project Fi Coverage Details

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General Coverage Information:

The coverage map for a regular FI SIM card can be found here.
The coverage map for a data-only SIM can be found here.

Details about using Sprint:

Using the Sprint portion of Fi is similar to using a post-paid Sprint device.  You have full access to everything that a Sprint customer would while on-network.  This includes their “LTE Plus” deployment, which is their branding for carrier aggregation.  As far as voice is concerned, if you place a call while on Sprint LTE, the phone will drop back to a CDMA connection to place the call.  Sprint does not have VoLTE available to its own customers, so therefore it is also not available to Fi customers.  Additionally, you have access to the same roaming that a Sprint customer would.

PLEASE NOTE: We are in the process of confirming whether postpaid LTE roaming agreements are available to Fi customers.  The remainder of the roaming is available.

Details about using T-Mobile:

Using the T-Mobile portion of Fi is similar to using a post-paid T-Mobile device with one very notable exception.  You have full access to everything that a T-Mobile customer would while on-network, including Band 12, with the exception of VoLTE.  This is a very important differentiation to make because this may present a few issues depending on location:

  • When you place a call on T-Mobile, you will fall back to UMTS or GSM to complete the call.  Traditional T-Mobile users will complete the call without leaving LTE via VoLTE.
  • VoLTE is prioritized at the highest level on the T-Mobile LTE network.  If you use a VoIP solution, such as the Hangouts dialer, your traffic is treated no different than generic internet browsing.
  • Band 12 inherently lacks a circuit-switched voice solution.  ALL voice traffic on Band 12 via T-Mobile is routed via VoLTE.  Since Fi subscribers don’t have access to VoLTE, your phone should fall back to UMTS or GSM.  However, this may or may not happen for a number of reasons.  It is very possible that the call will just fail.
  • It has not yet been confirmed in the aforementioned situation whether T-Mobile will process a 911 call as VoLTE.  The phone is provisioned for it, so it is a possibility.
  • Additionally, Band 12 is being rolled out by T-Mobile to close some of the coverage gap between themselves and other carriers.  There are certain T-Mobile areas in the country that have only Band 12 deployed.  These areas are usually at the fringe of their coverage.  In this case, you have absolutely zero traditional voice service while using T-Mobile on your Fi device.  You will have to either force to a new carrier, or use a VoIP solution to make the call.

The limitations with VoLTE are strictly artificial.  The Nexus 6P is provisioned for VoLTE out of the box, and actually attempts to utilize it even with a Fi SIM card inserted.  The request is knocked down at the network level, as Fi and T-Mobile do not have VoLTE included as part of the deal.  Hopefully this changes in the future because of the above reasons.

PLEASE NOTE: We are in the process of confirming whether postpaid LTE roaming agreements are available to Fi customers.  The remainder of the roaming is available.

Details about using US Cellular:

US Cellular is rather new to the Fi game.  The US Cellular side of Fi is slightly different from what a US Cellular post-paid customer experiences, notably lacking the LTE roaming on T-Mobile (for obvious redundancy reasons).  If you are in a US Cellular native area, you will be able to connect to their LTE network just the same as one of their customers can.  If you place a voice call, you will automatically fall back to CDMA, as US Cellular hasn’t officially deployed VoLTE for even their own customers at this time (they are targeting Q1 2017 for deployment).  It hasn’t been stated whether VoLTE will be available to Fi customers once US Cellular turns it on, but considering the state of affairs with T-Mobile VoLTE, it’s highly doubtful.

The other area where US Cellular shines is actually when you are not in an US Cellular native market.  You have access to the same roaming agreements (sans LTE) as their own customers do.  This means that you have the ability to fall back to Verizon.  Again, LTE is not available from Verizon, but you have full access to their 3G/EvDO network, as well as their legacy 2G/1X network.  With Verizon being the coverage leader in the nation, this is very good.

General Notes about Coverage:

Between the three carriers Fi offers, and US Cellular’s ability to roam on Verizon, you have full geographical access to four of the top five networks in the country.  Additionally, T-Mobile allows roaming on AT&T in some areas where they lack a better roaming partner, so in some cases, you may have access to all five of the top networks through native service and roaming agreements.  All in one phone, with one phone number.  This is HUGE for rural and traveling customers.

International Coverage:

Fi offers international service in many countries throughout the world.  Check out their website here for current details, as this is a continually evolving situation.

Project Fi General Information

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Equipment:

Fi currently sells the Nexus 5X, Nexus 6P, Pixel, and Pixel XL.  You can also use a Nexus 6 if you already own one.

Pricing:

Pricing for the service is very straight forward.  The base cost for a single phone is $20 per month for Unlimited Voice and SMS.  Data is charged at $10 per Gigabyte used.  You must have at least one gigabyte included in your monthly plan.  Tethering is also included at the same rate.  The awesome part of the service is that you pay for exactly what you use.  If you use less than the amount of data you select, you receive a refund for the exact unused amount.  If you go over the amount of data you select, you simply pay for the exact amount of extra data used.  No surprises.

Family Plan:

You can add additional phones for $15 per phone.  The additional phones will pull from the same data bucket, and data is charged at the same rate.

 

 

Data-Only SIMs:

You can order (multiple) data-only SIMs from Fi for free.  They simply pull from your existing data bucket.  These SIMs are only provisioned for T-Mobile service, and can be used in any device you can shove them into (unlike the full Fi service which requires a Nexus or Pixel phone).  There is a separate coverage map for these SIMs, and they do work in some international locations.

Activation, Phone Numbers, and Porting:

At this time, you cannot port in a phone number from a location that T-Mobile does not have access to a number pool.  It doesn’t matter if you own the number, or if you have the number in Google Voice.  It cannot be done.  Hopefully this changes in the future.

Necessary LTE Bands by Carrier

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Each carrier in the United States uses different spectrum to deploy LTE.  Below is a list of which bands are necessary for full utilization of each carrier’s network:

Carrier2451213141725262930416671
AT&TXXXXXXXX
SprintXXX
T-MobileXXXXX
Union WirelessXXXXX
US CellularXX
VerizonXXXXX
Viaero

The above band numbers reference the following bands:

BandDescriptionBlocksFCC Radio CodeDownlinkUplink
2PCSA / B / C / D / E / FCW1930 - 1990 MHz1850 - 1910 MHz
4AWS-1A / B / C / D / E / FAW2110 - 2155 MHz1710 - 1755 MHz
5CellularA / BCL869 - 894 MHz824 - 849 MHz
12700MHz - LowerA / B / CWY and WZ729 - 746 MHz699 - 716 MHz
13700MHz - UpperCWU746 - 756 MHz777 - 787 MHz
14FirstNetNoneSP758 - 768 MHz788 - 798 MHz
17700 - LowerB / CWY and WZ734 - 746 MHz704 - 716 MHz
25PCS +A / B / C / D / E / F / GCW and CY1930 - 1995 MHz1850 - 1915 MHz
26Cellular +A / B / XCL and YC/YH859 - 894 MHz814 - 849 MHz
29700 - LowerD / EWY and WZ717 - 728 MHzN/A
30WCSA / B / C / DWS2350 - 2360 MHz2305 - 2315 MHz
41TD 2500VariousED2496 - 2690 MHzN/A
66AWS-3G / H / I / JAT2110 - 2200 MHz1710 - 1780 MHz
71600A / B / C / D / E / F / GWT617 - 652 MHz663 - 698 MHz

For more details on the different bands, please see this page.

Rogers Peak Cellular Site

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The Rogers Peak cellular site has been something of a ‘saga’ over the years.  For a very long time, the valley below was blanketed by great analog service provided by Western Wireless, which later became Alltel.  Unfortunately, sometime in 2011, this site was taken offline.  Who made this decision, and why this decision was made is still not clear.  The result however, is a complete loss of cellular coverage in the valley below, as well as the surrounding areas.

The location of all antennas on top of Rogers Peak is shown below.

36.2180000,-117.0850556

Current State of Affairs

AT&T and Commnet have both filed applications in the past with the FCC to add a site at Rogers Peak to their respective cellular licenses.  However, despite the site being added to both licenses as a listed location (at separate times), the site has now been removed from both.

AT&T also funded a comprehensive study about the feasibility of building a new tower structure on top of Rogers Peak in 2013.  In 2014, this study was completed.  It is unclear what became of all of this research, or where the stumbling block actually was that prevented deployment of the site.  I reached out to AT&T for any information, and have not received a response.  The full report can be viewed here.  (This report was sourced via a FOIA request from the National Park Service.)  Whatever happened, as previously stated, the site is no longer listed in AT&T’s license.

There is no documentation available from the FCC records that gives any indication to what happened to the site Commnet applied to deploy, nor whether it was utilizing existing infrastructure on the mountain, or a new structure.  The only information I was able to receive from my FOIA request was that there was a cost estimate provided by the NPS for the option of deploying a new “lite-site” adjacent to the existing structures.  The cost estimated to complete just the environmental impact survey was around $175,000.  Considering that the site could fit well within the already-developed land area on top of the peak, this seems astronomical and unreasonable, and may have contributed to Commnet dropping plans for the site.  I imagine that cost is more than the entire site itself should typically cost to deploy.

What has become clear is that the former equipment deployed by Western Wireless is either unused or removed.  Given that an AMPS base station typically consumes more power than a newer digital base station, there should be no logical barrier to a carrier coming in and leasing the space formerly occupied by Alltel, and using the former antenna mounting position(s) used by Alltel.  This may force a carrier into using an omni antenna instead of sectorized panels, however Commnet is already using omni antennas on the new Stovepipe Wells site that was just erected, so this doesn’t seem to be that great of an issue.  Also, Commnet is already using satellite backhaul on their two deployed sites within the park, so transport also shouldn’t be an issue.

No matter the reasoning, the loss of the Rogers Peak site has dealt a serious blow to public safety and convenience within the park.  There is no telling how many emergencies may come up in the future that could be averted by having a means of communication.  Death Valley is known for tourists coming in unprepared, and sometimes not living long enough to leave because of their lack of planning.  Cellular communication may be the difference between life and death in these cases.  While I do not feel that there is enough information on the table to pass judgement, given the extremely high cost quoted for an environmental survey on top of the peak, it appears that the NPS is making it rather difficult for a carrier to come in and provide service from this location.

UPDATE (08/16/2017):

The NPS has (thankfully) started the process to fix this issue and modernize the site at the top of Rogers Peak.  You can see the page dedicated to the process here.  AT&T does have plans included with this project to add a site (inside of a new shelter), which would finally restore service to much of the park that has been without since the old site went down.

Death Valley Cellular Coverage

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Many of the main tourist areas of Death Valley National Park used to be covered rather well with analog cellular coverage. Unfortunately, the analog site that provided service to most of the area (on top of Rogers Peak) has been decommissioned, and no replacement has been authorized by the NPS at this time.  It is extremely unfortunate that so much coverage was lost in the area. When the FCC set the permissible sunset date for analog service, they stated that “discontinuance of analog service shall not result in any loss of wireless coverage”. However, this clearly is not what happened in reality.

For more information on what’s currently happening at Rogers Peak, see this page.

There are currently only two cell sites within park boundaries at this time, and both are operated by Commnet Wireless. Both sites offer CDMA, GSM, and UMTS service. AT&T (Postpaid) and Verizon (Postpaid) have been confirmed to allow roaming on these sites; I have not seen any confirmation from Sprint and T-Mobile customers at this time.

The first site is located at Furnace Creek. The antennas are 60 feet above ground, or approximately 127 feet below sea level.

36.4573889,-116.8695000

Here is a photo of the site:

The parameters of this site are as follows:

CDMA:
- SID: 3002
- PN Offset: 72 / 240 / 408
GSM CellID:
- MCC/MNC: 311-040
- CellID: ?
UMTS CellID:
- MCC/MNC: 311-040
- CellID: DEC 06445 / HEX 192D

This site serves only the area immediately near Furnace Creek.  See this document for a plot of where Commnet anticipates coverage from this site.  Please note: this scan is black and white, and of terrible quality.  It was originally scanned in by the Inyo County Planning Department in 2010.

The second site is located at Stovepipe Wells. The antennas are 70 feet above ground, or approximately 112 feet above sea level.

36.6042500,-117.1451389

Here is a photo of the site:

The parameters of this site are as follows:

CDMA:
- SID: 3002
- PN Offset: 30
GSM CellID:
- MCC/MNC: 311-040
- CellID: ?
UMTS CellID:
- MCC/MNC: 311-040
- CellID: DEC 06814 / HEX 1A9E

This site serves the area in and around Stovepipe Wells.  See this document for a plot of where Commnet anticipates coverage from this site.

There is one additional site outside of park boundaries that provides some coverage within the park.  This site is located at Cerro Gordo, and is owned by AT&T.  As an AT&T site, there is no CDMA being broadcast; only GSM and UMTS.  The site was previously a CDMA-only site when owned by Alltel, but AT&T turned off all CDMA on June 23rd, 2013.  The antennas are 60 feet above ground, or approximately 9132 feet above sea level.

36.5303889,-117.7893333

The parameters of this site are as follows:

GSM CellID:
- MCC/MNC: 310-410
- CellID: ?
UMTS CellID:
- MCC/MNC: 310-410
- CellID: ?

There may be other small areas of service within the park due to reflection off of the taller features in the park.  These come from other sites well outside of the park’s boundaries.

Hopefully there will be some improvements to service within the park in the future.