Are you saying that you are seeing 4MHz wide signals? Or are you seeing
~200KHz wide signals seperated by 4MHz?
If you are seeing 4MHz wide signals, they are not GSM. There is most
another technology being transmitted.
If you are seeing ~200KHz wide signals spaced by 4MHz, these most likely
GSM signals. The spec states that the spacing between adjacent channels
200KHz, but that does not mean that an operator will place all of their
channels next to each other. In fact, it would be bad if they did this.
Keep in mind that the spacing between channels is 200KHz, but the
bandwidth of a GSM signal is ~270KHz. This means that if GSM channels
placed next to each other, ICI will increase significantly. Typically
is seen is a very sparse scattering of channels across the band.
Hope this helps,
On Jun 2, 2011 4:49 PM, “TheOperator” [email protected] wrote: