UMTS World Logo

3G Devices
3G Jobs
Last Words
Contact Us

UMTSWorld box

Co-location, Isolations

Spurious emissions are emissions, which are caused by unwanted transmitter effects such as harmonics emission, parasitic emission, intermodulation products and frequency conversion products, but exclude out of band emissions. This is measured at the base station RF output port.

emission mask

Spectrum Emission Mask, 3GPP TS 25.104 Fig. 6.2


Spurious emissions limits for protection of the BS receiver

The table above corresponds to -80 dBm / 3.84MHz spurious emission requirements from UMTS DL to UMTS UL.


Spurious emission DL to UL
- 80 dBm
  See above
Max sensitivity degradation
- 121 dBm
  BS reference sensitivity
Min required isolation
 41 dB

UMTS FDD isolation requirement due to spurious emissions
Note: Check with your vendor, they will quote a lower figure

The receiver blocking characteristics is a measure of the receiver ability to receive a wanted signal at its assigned channel frequency in the presence of an unwanted interferer on frequencies other than those of the adjacent channels.


Max Node B power
  43 dBm
  = 20W
Blocking level
- 40 dBm
  3GPP 25104 7.5.1
Min required isolation
 83 dB

UMTS FDD - FDD isolation requirement due to receiver blocking
Note: Check with your vendor, they will quote a lower figure

The transmit intermodulation performance is a measure of the capability of the transmitter to inhibit the generation of signals in its non linear elements caused by presence of the wanted signal and an interfering signal reaching the transmitter via the antenna. The transmit intermodulation level shall not exceed the out of band emission or the spurious emission requirements.

Summary: Co-location and isolation related issues
  • Co-location issues; base station receivers; spurious emission and blocking
  • Co-existence issues; mobile phone receivers; spurious emission and blocking
  • Intermodulation issues
  • All wireless systems need to be considered
  • Vendor equipment specification far better that 3GPP specifications

    Solution considerations
  • Equipment specifications
  • Horisontal antenna separation
  • Vertical antenna separation
  • Additional filtering
  • Antenna beamwidth
  • Antenna bearing
  • Frequency coordination with other carriers
  • Smart designs for common antenna systems

    Further reading: 3GPP TS 25.104, GSM 05.05, ITU-R SM.329-9

      UMTS Overview UMTS Network UMTS Frequencies UMTS Coding UMTS Link Budget
    UMTS Security UMTS Codes Synchronisation Co-location
    3G Data Speeds UTRA Time Slots UTRA Channels WCDMA Spreading
    UMTS QoS Channel Coding Media Formats Compressed Mode
    UMTS HSDPA UMTS Handovers Location Services UMTS Power Control
    UMTS Overview Cell Search Random Access RCC States Iui Frame Structure
    CDMA Overview Call Setup UTRAN Interfaces Paging Virtual Home Environment

  • | Advertise | Support Us | Contribute | Site Map | Legal | Privacy | About | Notes|
    Copyright 1999 - 2003