I've had a few PMs asking about the different 4G bands, frequencies, and how to see what band is being used. iPhone users have the built in Field Test which shows this but Android doesn't offer anything which can query the band so you often have to try and find out a code to access an engineering menu which might not always be available. However there is another way.
In a different thread the LTE Discovery app was suggested as a way of getting the band. This app doesn't actually query the phone for the band but uses the cell ID and based on samples tries to build a picture of how a network allocates its cell IDs. The trouble is this takes time so networks aren't supported at first and even if they are some phones don't work with the app. But you can do it yourself so earlier this week I had a look at how the networks were assigning cell IDs based on band.
What you'll need
The trouble with cell IDs is that there are different types and ways to show them. For 4G a lot show the E-UTRAN ID (ECI) but this is actually a concatenation of two IDs, the eNodeB (eNB) and a local Cell ID. To do this the easy way install an app that shows the local Cell ID separately. There are probably lots of apps that do this but I know G-NetTrack is one (satisfy yourself with permissions). You can skip the next bit on Cell IDs if you don't care about this and go straight to the mapping cell ID to band part below with the result you have from the app.
Cell IDs
The Cell IDs that a lot of apps show for 4G is the ECI (this is also what is shown by an iPhone in the cell identity field). This is a concatenation of the eNB which can be any number up to 20 bits long and an 8 bit local cell ID. An eNB is the 4G equivalent of a base station in 2G so it might be easier to think of it as the site (even if this isn't strictly correct).
So for coverage in Canary Wharf in London for example, EE have an eNB with an ID of 10734 and one particular sector cell has a cell ID of 7. The ECI for this will be 10734*256 + 7 = 2747911. This is what an iPhone or an app like Network Signal Info will display.
To work backwards from the ECI starting with 2747911 expressed in binary (plenty of online converters if you search) gives you 1010011110111000000111. The final 8 bits (00000111) converted to decimal is 7 and the earlier part (10100111101110) in decimal is 10734. Some apps might show the ID in hex and this is also an easy way to convert. e.g. 2747911 in hex is 29EE07. the cell ID is 07 and 29EE is the eNB.
Mapping Cell ID to Band
Depending on your network, for up to three sector sites, the cell IDs are as follows.
EE
1800MHz (band 3) - Cell IDs 0, 1, 2
2600MHz (band 7) - Cell IDs 6, 7, 8
Vodafone
800MHz (band 20) - Cell IDs 10, 20, 30
2600MHz (band 7) - Cell IDs 18, 28, 38
Three
1800MHz (band 3) - Cell IDs 0, 1, 2
800MHz (band 20) - Cell IDs 6, 7, 8
O2
All O2 4G is on 800MHz (band 20).
A few notes. I've based this on what I've seen in London and the surrounding area this week but it has been 100% correct. I can't discount that there are different allocations in use elsewhere so it would be helpful if others could check they get the same results. Even if you don't have access to the less common bands in your areas it still helps to see if the normal 4G bands follow this pattern elsewhere.
The other caveat that I thought of is what if the numbering system isn't based on band but on cell order. So on Three 1800 came first and so got 0,1,2 with 800 getting 6,7,8 later. If they rolled out an 800 only site might it then be allocated 0,1,2 ?
Also note that at the moment, despite extensive coverage, unless you can force the band, Three users will not see 800MHz. It's open to use but phones will select 1800MHz 4G and 3G in preference to 800MHz 4G because of how it's currently set up.
I've not seen an EE 800MHz site so can't say what this shows. If anyone knows where there are any in use around London let me know and I'll try and have a look if I'm near.
In a different thread the LTE Discovery app was suggested as a way of getting the band. This app doesn't actually query the phone for the band but uses the cell ID and based on samples tries to build a picture of how a network allocates its cell IDs. The trouble is this takes time so networks aren't supported at first and even if they are some phones don't work with the app. But you can do it yourself so earlier this week I had a look at how the networks were assigning cell IDs based on band.
What you'll need
The trouble with cell IDs is that there are different types and ways to show them. For 4G a lot show the E-UTRAN ID (ECI) but this is actually a concatenation of two IDs, the eNodeB (eNB) and a local Cell ID. To do this the easy way install an app that shows the local Cell ID separately. There are probably lots of apps that do this but I know G-NetTrack is one (satisfy yourself with permissions). You can skip the next bit on Cell IDs if you don't care about this and go straight to the mapping cell ID to band part below with the result you have from the app.
Cell IDs
The Cell IDs that a lot of apps show for 4G is the ECI (this is also what is shown by an iPhone in the cell identity field). This is a concatenation of the eNB which can be any number up to 20 bits long and an 8 bit local cell ID. An eNB is the 4G equivalent of a base station in 2G so it might be easier to think of it as the site (even if this isn't strictly correct).
So for coverage in Canary Wharf in London for example, EE have an eNB with an ID of 10734 and one particular sector cell has a cell ID of 7. The ECI for this will be 10734*256 + 7 = 2747911. This is what an iPhone or an app like Network Signal Info will display.
To work backwards from the ECI starting with 2747911 expressed in binary (plenty of online converters if you search) gives you 1010011110111000000111. The final 8 bits (00000111) converted to decimal is 7 and the earlier part (10100111101110) in decimal is 10734. Some apps might show the ID in hex and this is also an easy way to convert. e.g. 2747911 in hex is 29EE07. the cell ID is 07 and 29EE is the eNB.
Mapping Cell ID to Band
Depending on your network, for up to three sector sites, the cell IDs are as follows.
EE
1800MHz (band 3) - Cell IDs 0, 1, 2
2600MHz (band 7) - Cell IDs 6, 7, 8
Vodafone
800MHz (band 20) - Cell IDs 10, 20, 30
2600MHz (band 7) - Cell IDs 18, 28, 38
Three
1800MHz (band 3) - Cell IDs 0, 1, 2
800MHz (band 20) - Cell IDs 6, 7, 8
O2
All O2 4G is on 800MHz (band 20).
A few notes. I've based this on what I've seen in London and the surrounding area this week but it has been 100% correct. I can't discount that there are different allocations in use elsewhere so it would be helpful if others could check they get the same results. Even if you don't have access to the less common bands in your areas it still helps to see if the normal 4G bands follow this pattern elsewhere.
The other caveat that I thought of is what if the numbering system isn't based on band but on cell order. So on Three 1800 came first and so got 0,1,2 with 800 getting 6,7,8 later. If they rolled out an 800 only site might it then be allocated 0,1,2 ?
Also note that at the moment, despite extensive coverage, unless you can force the band, Three users will not see 800MHz. It's open to use but phones will select 1800MHz 4G and 3G in preference to 800MHz 4G because of how it's currently set up.
I've not seen an EE 800MHz site so can't say what this shows. If anyone knows where there are any in use around London let me know and I'll try and have a look if I'm near.
