boomerbubba

I think the Full Internet Access is because of the mapping feature built in. CDMA Field Test takes you out of the program to look at maps of site locations. Which is kind of wonky. But allows the program to not need internet access.

 

Robert via CM9 Kindle Fire using Forum Runner

Maybe. CDMA FT does only map one site at at time, just passing the coordinates. And Nemonitor's map display is certainly handy. (I still prefer to export the data and map it myself anyway.) The developer never mentioned that functionality in our email conversation. He indicated the Internet access is required for whatever method the app uses to try finding GSM locations. There is an Android mapping API that does not require setting up a generalized Internet socket, which is what Netmonitor does. That same socket could also be used for any purpose, and the user would really have no way to know for sure.

Unfortunately, Google sometimes bundles Android permissions a little too broadly. For example, an audio app might have a legitimate need to detect that there is an incoming phone call to suppress music output. But giving it permission to do that also gives permission to know my phone number and the number I am connected to.

The way the Android ecosystem works, all end users are responsible for their own safe computing after being notified of permissions, which 99 percent of users don't understand. Heck, I consider myself pretty knowledgeable, but I know I have tapped through those permissions when installing apps lots of times. I had to go research this stuff to find out what the permissions meant.

The net effect of generalized permissions and fallible human users is that there are some very questionable apps being installed out there. And it is easy to forget that when granting permissions, we users are not granting them just to Google -- or Microsoft, Apple, Facebook, etc. -- corporations with a domestic address and a published privacy policy, but to developers who for all practical purposes are anonymous and beyond legal recourse. A particular developer, known only through his Gmail persona, may be quite benign. But he may also be harvesting private information (phone call records, IMEIs, locations, etc.) for scummy marketers, stalkers, hackers etc. just through social engineering.

More egregiously and obviously, right now you can find half a dozen apps on the Google Play market that purport to "boost" the user's cell connection by "optimizing" it or some similar snake oil. I think that advertised functionality is mostly a phony placebo, just resetting the phone or something similar by toggling settings. But if you look at the permissions granted to those apps (which overlap with much of Netmonitor's permissions, including Internet access) they seem to be poised to rape the user's privacy in the background. These apps have tens of thousands of downloads.

So I just get suspicious in the presence of three things:

• Developer is basically an anonymous stranger.
  
• App has permissions to read a lot of private data.
  
• App has full Internet permissions.
  

Again for the record, I received an email from the Netmonitor developer, who says that one recently added feature as been removed in a new version:

Crash report is removed from version 0.11.4. Thanks

I checked Google Play, and the specific permission for Netmonitor to "read sensitive log data" is no longer there. This effectively backs out the expanded perimission that the most recent prior version had requested. All the other permissions remain, notably including full Internet access, and there is no feature of Netmonitor I use that requires that. I still can get what I need from CDMA Field Test, which has less intrusive permissions and no Internet access. So a decision to install Netmonitor comes down to how much one trusts the developer.

So how can you accurately tell where the towers are and which ones your connecting to?

Apps such as CDMA Field Test will accurately capture the Network IDs and Base Station IDS broadcast by the tower radios you connect to, along with a lat/lon coordinate for each sector BSID. The Sponsor-accessible maps at S4GRU accurately map the towers themselves. Correlating the coordinates to actual tower sites depends on the configuration of each tower, which fits one of two cases:

• Some BSID coordinates for all three sectors per tower closely match the coordinates on their tower.
  
• Other towers are configured such that each sector squawks coordinates offset some distance from the tower, the three forming a triangle.
  

So correlating the BSIDs to towers is a bit of a trial-and-error art, but it is quite possible once you get the hang of it. You will need to figure out which of these configurations fits your tower. You might need to travel around the tower to log all three sector BSIDs.

If I wanted to inquire about a tower, what identifier would I use?

Inquire to whom? Frontline Sprint reps? They may not know much anyway, and are good at playing dumb if they do know stuff.

The identifiers picked up by apps such as CDMA Field Test, etc., are network IDs that fit the CDMA standard and are broadcast. There is a hierarchical set of codes that identify, system, operator, network and base station. Each base station represents a sector, and there are typically three sectors per tower. There is no ID in this hierarchy that corresponds one-to-one to a tower, although Sprint's practice seems to be to assign sequential BSIDs to the sectors of each tower. These sector base stations also broadcast lat/lon coordinates, which might all coincide exactly with the tower location. However, some of those BSID sector coordinates are not the actual tower locations but rather are offset in a triad pattern. We don't know why.

If you become a sponsor here and see the project maps, they are tower-oriented. There is an identifier, apparently assigned by Sprint, visible per tower on the S4GRU maps. The coordinates of the towers are accurate. There is no easy way here to correlate the tower IDs to the CDMA network IDs in a table. Such tables surely exist somewhere within Sprint, but we still don't have them.

Sorry, I can't see the tag on tapatalk. I guess what I should've said is that the Sprint coverage map is not an accurate representation. The S4GRU information gives a better reflection of what's actually available.

 

Sent from my GS3 on Tapatalk 2

But we should understand that the S4GRU tower maps do not purport to be coverage maps, like Sprint's own maps do.

To compute geographical signal coverage for the towers, it would be necessary to use software that includes lots of other inputs, such as azimuths and downtilt angles for each sector on a tower, along with physical and man-made topography. I think there once was an ambitious goal in these parts to built such theoretical coverage maps using the resources at CloudRF.com, but that apparently was not feasible.

So we just have to tower points which are way better than nothing. And since Sprints coverage maps seem to be, uh, optimistic, having the actual tower sites is a good reality check.

I used open signal maps today under the Maps setting, and I could visually see the towers I was connected to. 2 of the 6 or so I connected to had LTE. There was one tower, oddly enough closest to my house that I can't find for the life of me. Drove around 2 neighborhoods, wasn't there, or its in somebody's house! LOL ,my daughter said its underground (which explains a lot.) : )

Open Signal's "tower" locations are just guesses based on crowdsourced signal-receptions data. They are notoriously inaccurate. Even Open Signal's page on the Google Play market site warns about inaccuracies.

There are other apps, such as CDMA Field Test, that report lat/lon coordinates broadcast by the sector base stations themselves. In some cases, those sector coordinates match the actual tower location. But in others, each sector's base station on a given tower reports different coordinates offset by some distance, possibly miles away in large cells. We don't know why this is.

Duplicate post.

Thats good info thanks. I actually visted one of the sites a mile from my job that is due to be a NV upgrade. Its only a mile away but lord know based on my covereage at my job I have never connected there. Do you know any other Apps like Opensignal that I can use to compare?

Try CDMA Field Test. Open SIgnal's tower locations are inaccurate guesswork based on crowdsourcing.

One caveat: The tower coordinates captured by CDMA Field Test and similar apps will be the lat/lon broadcast by the sector base stations and captured by the Android device. But there seem to be two distinct situations: On some towers, all sector base stations will squawk the actual coordinates of the tower; on others, each sector will squawk different coordinates that are offest some distance away from the tower.

Why is sprint launching these markets with such a low completion percent (Dallas is 9%!)?

I wondered the same thing. My surmise is that this is mostly just a reporting lag within S4GRU, although it was understood that there would be something less than 50 percent at the official launch.

Their strategy probably has more to do with how they can complete zoning and permits, as well as where is easiest to get backhaul to first.

I doubt that zoning and permits have much to do with this, since the NV sites in almost all cases are using the legacy towers.

For the record, I have received another email from the Netmonitor developer:

If you have problems with privileges, don't use it.Cell location from tower is only available in CDMA and not on all towers, so Google Geolocation API is used. I do not collect any data.

I am unpersuaded, except for the suggestion that I just don't use the app.

But I may be wrong about the capabilities of CDMA Field Test. It does not seem to capture coordinates in its log, even though there are values displayed in the app' s main screen for one BSID at a time. (I saw another user here in another thread say he logged coordinates with this app, so I am confused.)

Edit: Thanks to tutoring from nseabrook, I now see that CDMA Field Test's logging of both coordinates and signal strength works after all. The trick is that the user must tap the button to email the logs, not just view them onscreen. That includes both a kml file and a csv file. I can work with that just fine.

Netmonitor still leaves me queasy. I prefer not to use it.

You can set it to sniff all WiFi traffic in a given area (if the connection is unencrypted). Or if the connection is encrypted, I think you can still sniff anything on your LAN. Been awhile since I used it though.

But that still captures only WiFi. I don't know of any way to sniff Internet traffic over the air via Sprint.

Sent from my SPH-D700 using Tapatalk 2

Know how to use Wireshark? Install it on a computer on your local network, connect your phone to the same network, then fire up NetMonitor. You'll be able to see all traffic that transpires from your phone to whatever it's connecting to, NetMonitor included.

 

My guess is that the phone will ask Google for its location, given a few parameters, so it can get a quicker GPS fix/tell where it is even if you don't have GPS turned on. Other than that, no information will be sent or received.

 

Some developers are sloppy with the permissions they require on Google Play; it's just an XML file (having done Android development in the past) that guarantees that those functions will be available to the app if it needs to use them. The app doesn't have to use that functionality.

Wireshark could be set up to sniff your own WiFi traffic, I think, but not OTA data.

If you wanted to create your own app that provided these same features, and maybe even some from CDMA Field Test and Debug...all without the privacy problems, I would be willing to pay some money for it. I think most network geeks would pay $10-$20 for such an app.

 

Robert

Unfortunately I lack the hands-on Java and Android programming skills, although I have enough knowledge as an analyst to read the docs and know generally what is possible.

For the time being, I will use CDMA Field Test intractively and view its simpl e maps. For more complex multisite maps, it is easy to export. Edit: Now I am no longer sure CDMA Field Test can log coordinates, even though it captures them interactively. Still exploring that.

Like many here, I have used Netmonitor as a tool to try mapping local Sprint towers. But recently I have investigated its privacy settings, and decided to uninstall the app. I wish I had never installed it.

Basically, the Android permissions granted to this app would allow it to harvest my phone number and those I contact, the unique IMEI of my device, my location, my WiFi settings, and other detailed data on my Android phone. Plus, it has unlimited Internet access so any harvested information could be sent to any server anywhere without my knowledge. The most recent version asks to expand the privileges even further to read sensitive log data.

I can't know that the app is actually doing anything I wouldn't like with my private information, but anyone installing it has to trust the developer not to do so, having granted the Android app permissions. But who is that developer? He has no published identity beyond an Gmail address, and no published privacy policy. I don't even know where he is, but the app's example screenshots on the Google Play site show locations in Belarus. The developer has responded to email questions, but I find the responses very unsatisfactory.

According to Google's Play market site, here are the sweeping permissions that Netmonitor is granted when installed:

This application has access to the following:

 

Your location

coarse (network-based) location

Access coarse location sources such as the cellular network database to determine an approximate tablet location, where available. Malicious apps may use this to determine approximately where you are. Access coarse location sources such as the cellular network database to determine an approximate phone location, where available. Malicious apps may use this to determine approximately where you are.

fine (GPS) location

Access fine location sources such as the Global Positioning System on the tablet, where available. Malicious apps may use this to determine where you are, and may consume additional battery power. Access fine location sources such as the Global Positioning System on the phone, where available. Malicious apps may use this to determine where you are, and may consume additional battery power.

Network communication

full Internet access

Allows the app to create network sockets.

Your personal information

read sensitive log data

Allows the app to read from the system's various log files. This allows it to discover general information about what you are doing with the tablet, potentially including personal or private information. Allows the app to read from the system's various log files. This allows it to discover general information about what you are doing with the phone, potentially including personal or private information.

Phone calls

read phone state and identity

Allows the app to access the phone features of the device. An app with this permission can determine the phone number and serial number of this phone, whether a call is active, the number that call is connected to and the like.

Storage

modify/delete USB storage contents modify/delete SD card contents

Allows the app to write to the USB storage. Allows the app to write to the SD card.

System tools

change Wi-Fi state

Allows the app to connect to and disconnect from Wi-Fi access points, and to make changes to configured Wi-Fi networks.

prevent tablet from sleeping prevent phone from sleeping

Allows the app to prevent the tablet from going to sleep. Allows the app to prevent the phone from going to sleep.

Network communication

view network state

Allows the app to view the state of all networks.

view Wi-Fi state

Allows the app to view the information about the state of Wi-Fi.

I emailed the developer, asking why all these permissions are justified. I also asked who he is and where is a published privacy policy. The answer I got seemed like incomplete doubletalk to me:

Internet is used to get cell location from Google, when app crashes it sends logcat logs if you allow, so I can fix the problem. Thanks.

In fact, the cell location does not come from Google on the Internet, but rather gets them directly from the Android's own API, which gets the coordinates over the air from the cell towers themselves. Several other apps, such as CDMA Field Test, do this without any Internet access at all.

(The app's help screen does include another possibility for cell site location, which I have never seen in practice. That other possibility is referred to as "coordinates came from Gears Geolocation API." But Google says the Gears API is deprecated and is no longer available. Even when it did exist, Gears geolocation did not provide a tower location, but the phone's own estimated location. And location is available to an Android app directly from the Android API by the Location permissions alone.)

Although CDMA Field Test is not quite as handy, I think it does basically what Netmonitor does for me, but without the privacy concerns and without all the intrusive permissions. In fact, it has no Internet permissions. So I am uninstalling Netmonitor.

when i was in the area i was connecting to three towers one not in pic just north of my location. i have a screen shot of the tower but im getting file is too large to post here.

I see. Do be advised that the sites mapped by Netmonitor here, at least in the screenshot that maps the two sites labeled 03809 and 03795, are not actual Sprint tower locations. (Sponsor-level members here can see maps of the actual towers.) Netmonitor is plotting the coordinates broadcast by these two base station radios, but these coordinates apparently are offset some distance from their towers' actual sites. This phenomenon occurs on many Sprint towers, although many others broadcast their actual locations. So the LTE base station you logged (12706) may not be where your map shows it, either.

I was making a delivery in west houston about a hour and was able to connect to 4g

Your first Netmonitor screenshot does indeed show an LTE connection, but it is not the same base station mapped in the other screenshot. Between those snapshots, your connection must have changed. Or something else is awry.

I used "Open Signal Maps".

Didnt know about this app. Comment say this thing is running in the background? Not good.

Open Signal is primarily an online app that crowdsources coverage areas and guesses at tower sites from that data. The tower guesses are not very accurate. I think it does run in the background if you give it permission to collect and post your logged signal strength data to their website.

I work in an EMI Proof building. It's basically a giant Farraday cage. As soon as you walk in the door, the cell coverage drops out. Some years ago, before LTE was a thing, they installed cell repeaters. Would these older repeaters be able to pass LTE, or will I be stuck on EV-DO at work?

I don't know who the manufacturer of your repeater product is, so the question needs to be posed to them. I wondered the same thing generally, so I made an inquiry recently to Wilson Electronics, which seems to be a market leader in repeater products for both vehicles and buildings. The response, in another thread, indicated that their frequency coverage will have to be tweaked to handle Sprint's LTE channels.

Their response said it was just a problem of frequency bands, not LTE technology itself. But sInce I made that post, I have wondered further about how MIMO (dual antennas) in LTE might be affected, since the repeaters are built around a single antenna.

I don't have an urgent need in this regard, but I am interested to see what happens.

still getting LTE and signal/speeds seems to be better than just a couple of hours ago...

(Houston, TX - SW side near West Oaks Mall)

 

 

 

FWIW, don't take Netmonitor's site map too literally. The screenshot above shows you connected to an LTE sector base station, BSID 833 (00833 on the map). But that mapped location, derived from the base station's broadcast coordinates, is not the actual tower site. (Tower site maps are available to sponsors.)

This seems to be another example of tower base stations that squawk coordinates offset from the tower location. So now we know that this phenomenon persists after the NV rollout. Some sites broadcast actual tower coordinates for all sectors; but others will broadcast offset coordinates, typically in a triad pattern around the tower.

Max speeds and areas of low population density will be faster as more spectrum is refarmed for LTE and LTE advanced is rolled out,...

One thing I have never quite understood about the first phase of the Network Vision project is this: Since there will be both LTE base stations and EVDO/eHRPD base stations on the same towers using the 1900 band, will they be able to share the same frequency channels, or does the LTE expansion actually need different spectrum within that band than the legacy EVDO base stations use today?

Ooooh Where are robert's maps I haven't had a chance to look through them yet.

In the Interactive S4GRU Maps forum. A handy geography-based index to the master maps is pinned near the top.

boomerbubba, the issue is really a debate between two signal metrics: RSSI vs RSRP. Both use dBm as the unit of measurement, but they differ in ways that can make RSSI report signal levels ~25 dB greater than that of RSRP.

 

RSSI, which is a more traditional measurement that has long been used for various airlinks, measures all RF energy in the channel. RSRP, which is an LTE specific measurement, measures only the average power of many reference signals in the channel.

 

HTC's FieldTrial.apk reports RSRP (and RSRQ, but I will not go into that metric right now), while Android ICS may report RSSI. On the latter count, I am not sure. And I do not live within the current LTE footprint, so I cannot presently compare and contrast the reported signal levels. I can say that VZW has made a push to standardize RSSI for LTE signal reporting; thus, it would not surprise me if Android has followed that lead.

 

Due in part to your relevant questions, Robert and I have decided that now would be a good time to write up an article on LTE signal metrics. So, I will start working on turning this post into a full fledged article to be published on The Wall, ideally tomorrow afternoon.

 

AJ

I look forward to that article. I must say, I was confused just looking at the RSRP LTE signal levels you reported in your original post, which to my untutored mind seemed surprisingly weak. But I am probably used to the RSSI signal levels more commonly reported for 3G and 1X.

Hope so! My girlfriend's parents are in the Columbia market. You can check if the tower is Sprint by looking at opensignalmaps.com perhaps?

Tower locations in opensignalmaps are junk estimates. To see the actual Sprint tower locations, you should become a sponsor and view Robert's maps.

I'll probably cancel the addon once I get back to Colorado though, since I do have other ways of getting connectivity on the go (T-Mobile HSPA+ data stick and Verizon LTE iPad). But the tethering plan should be fun while it lasts (and a heck of a better deal versus Verizon's 1GB, $20 plan).

Is this $20/month add-on service prorated per day, like the previous service priced at $30/month was?