I have a Samsung Galaxy Ace, with quad-band I believe. It is possible to see the current connection network type, e.g. UMTS, EDGE, etc, by going to Settings -> About Phone -> Status. But it does not tell which frequency band it is on. Is it possible to find out which frequency band (either exactly, or just which of the four major bands) that I am using?
Based on avirk's hint, I found a way. First press the code *#0011#
GSM900: IDLE T: 10, B: 10 Rx Pwr: -94, Rx ual: - Rx Lev: 21, Tx Lev: 0- Speech VER: AMR EFR FR VOC: AdaptiveRate TS: 0 Temp: 68 Batt: 71 LNA: 0 Service: Available
It is obvious that it's using 900MHz band, from the "GSM900".
UMTS WCDMA example:
WCDMA: Idle Rx CH: 10612, R: -94 Tx CH: 9662, Tx Pwr: - EdIo: -6, RSCP: -98 SpeechVER: AMR EFR FR RF: Sleep2 L1: PCH_Sleep Drx cycle: 64, PSC: 392 Temp: 67 Batt: 69 LNA: 0 Service: Available
UMTS can use two different physical layers (low level radio) UMTS-FDD and UMTS-TDD. Android just shows WCDMA, which I think is the same as UMTS-FDD, but perhaps it can refer to both of them. By looking up the channel number here you can tell the frequency bands and whether it is UMTS-FDD or UMTS-TDD.
In the above example it is using UMTS-FDD, the down-link channel (Rx) is in the 2100MHz band and the up-link channel (Tx) is in the 1900MHz band.
LTE Discovery app tells this for 4G/LTE.
Have you tried using MTK engineering tool? It works pretty well for most android phones i've come across as it also shows you the current 4G bands.