The first ten wireless bands for co-location are listed in the table.
|Type of Co-located BS||Freq. Range for Co-location Requirement||Basic Limits||Measurement Bandwidth|
|WA BS||MR BS||LA BS|
|GSM900||876-915 MHz||–98 dBm||–91 dBm||–70 dBm||100 kHz|
|DCS1800||1710-1785 MHz||–98 dBm||–91 dBm||–80 dBm||100 kHz|
|PCS1900||1850-1910 MHz||–98 dBm||–91 dBm||–80 dBm||100 kHz|
|GSM850 or CDMA850||824-849 MHz||–98 dBm||–91 dBm||–70 dBm||100 kHz|
|UTRA FDD band I or E-UTRA band 1 or NR band n1||1920-1980 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
|UTRA FDD band II or E-UTRA band 2 or NR band n2||1850-1910 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
|UTRA FDD band III or E-UTRA band 3 or NR band n3||1710-1785 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
|UTRA FDD band IV or E-UTRA band 4 or NR band n4||1710-1755 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
|UTRA FDD band V or E-UTRA band 5 or NR band n5||824-849 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
|UTRA FDD band VI, XIX, or E-UTRA band 6, 19||830-845 MHz||–96 dBm||–91 dBm||–88 dBm||100 kHz|
For instance, if the 5GNR BTS is co-located with a wide-area base station operating in the PCS1900 band, then its transmitter output power must not exceed –98 dBm/100 kHz in the 1850 MHz to 1910 MHz frequency range at any time. This is the basic limit as indicated in the previous table. There are sub-clauses for mMIMO systems that have many antenna ports. On the receive direction, the 5G receiver must have the dynamic range specified in the following table [REF 1 Table 7.5.3-1]. Specifically, for a wide-area base station, it must be able to tolerate an out-of-band continuous wave (CW) signal at +16 dBm at the receiver connector without degrading its receiving sensitivity by more than 6 dB.
|Freq. Range of Interfering Signal||Wanted Signal Mean Power (dBm)||Interfering Signal Mean Power for WA BS (dBm)||Interfering Signal Mean Power for MR BS (dBm)||Interfering Signal Mean Power for LA BS (dBm)||Type of Interfering Signal|
|Frequency range of co-located downlink operating band||PREFSENS +6 dB 1||+16||+8||X 2||CW carrier|
While this is the 3GPP compliance specification, most network operators prefer that the 5G receiver sensitivity level does not get degraded at all. Along with the transmit direction, these specifications are much more stringent than without co-location.
In subsequent sections, the meaning of these co-location requirements are examined in terms of filtering needs and the implications on receiver architecture design to handle such high dynamic range. Specifically, a working example of the recently auctioned C band in the U.S. is analyzed, with a frequency range from 3700 MHz to 3980 MHz. It will be shown that these co-location requirements do not impose any significant additional filtering requirements when using direct RF sampling versus direct conversion transceivers (RFICs).