Tmobile bought up quite a bit of the 700MHz spectrum, but I wanted to see where it was being deployed.

Map of Deployments and other Information
http://maps.spectrumgateway.com/t-mobile-700-mhz-spectrum.html

How to find current band on iPhone
Open the Dialer
*3001#12345#*
Press Dial/Talk
This enables Field Test Mode
Navigate to LTE > Service Cell Info
Where it says Freq_band_ind that’s the band you’re currently utilizing. In my case it’s Band 2

http://www.radio-electronics.com/info/cellulartelecomms/lte-long-term-evolution/lte-frequency-spectrum.php

LTE BAND
NUMBER DOWNLINK UPLINK WIDTH_OF_BAND DUPLEX_SPACING BAND_GAP
1 1920 – 1980 2110 – 2170 60 190 130
2 1850 – 1910 1930 – 1990 60 80 20
3 1710 – 1785 1805 -1880 75 95 20
4 1710 – 1755 2110 – 2155 45 400 355
5 824 – 849 869 – 894 25 45 20
6 830 – 840 875 – 885 10 35 25
7 2500 – 2570 2620 – 2690 70 120 50
8 880 – 915 925 – 960 35 45 10
9 1749.9 – 1784.9 1844.9 – 1879.9 35 95 60
10 1710 – 1770 2110 – 2170 60 400 340
11 1427.9 – 1452.9 1475.9 – 1500.9 20 48 28
12 698 – 716 728 – 746 18 30 12
13 777 – 787 746 – 756 10 -31 41
14 788 – 798 758 – 768 10 -30 40
15 1900 – 1920 2600 – 2620 20 700 680
16 2010 – 2025 2585 – 2600 15 575 560
17 704 – 716 734 – 746 12 30 18
18 815 – 830 860 – 875 15 45 30
19 830 – 845 875 – 890 15 45 30
20 832 – 862 791 – 821 30 -41 71
21 1447.9 – 1462.9 1495.5 – 1510.9 15 48 33
22 3410 – 3500 3510 – 3600 90 100 10
23 2000 – 2020 2180 – 2200 20 180 160
24 1625.5 – 1660.5 1525 – 1559 34 -101.5 135.5
25 1850 – 1915 1930 – 1995 65 80 15
26 814 – 849 859 – 894 30 / 40 10
27 807 – 824 852 – 869 17 45 28
28 703 – 748 758 – 803 45 55 10
29 n/a 717 – 728 11
30 2305 – 2315 2350 – 2360 10 45 35
31 452.5 – 457.5 462.5 – 467.5 5 10 5