Most Powerful Open Source ERP

EIRP Test B38

Describe the ORSB38 EIRP in regard to European regulation.
  • Last Update:2025-11-24
  • Version:004
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Introduction

This page describes the test executed by Rapid.Space of EIRP for our product ORS 2 x 1W Band B38 (2570MHz-2620MHz), according to the requirement raised by The ECC Decision (05)05 (REV 2022). The objective of this measurement is to validate the conformance of the ORS Band 38 (TDD Mode) with the specified power limits for Active Antenna Systems (AAS) and non-AAS base stations.

The ECC Decision (05)05 (REV 2022) focuses on the harmonized utilization of the 2500-2690 MHz spectrum band for Mobile/Fixed Communications Networks (MFCN) in Europe, which defines the criteria for power limits for AAS (Active Antenna System)  and non-AAS base stations using Total Radiated Power (TRP) and Equivalent Isotropically Radiated Power (EIRP). For more detail, please refer to the published document. 

This decision outlines several technical requirements that concerning our products that our product ORS Band 38 (TDD Mode) is obliged to execute a test to conclude a proper setting corresponding to the requirements in this decision. 

Regulatory Framework and Technical Specifications

1. Two related frequency bands are allocated in this decision : 

  • FDD Mode (Frequency Division Duplex)
    • 2500-2570 MHz: Uplink (Mobile transmit)
    • 2620-2690 MHz: Downlink (Base station transmit)
  • TDD Mode (Time Division Duplex)
    • 2570-2620 MHz: Can be used for TDD or Supplemental Downlink (SDL).
  • Channelization
    • Assignments are in multiples of 5 MHz.

2. Power limits for related Base Stations : 

Non-Active Antenna Systems (Non-AAS)

  • Maximum EIRP (Equivalent Isotropically Radiated Power) per antenna
    • 61-68 dBm/5 MHz per antenna (Administrations may apply limits within this range).
  • Baseline Emissions
    • FDD DL, SDL, and synchronized TDD blocks: +4 dBm/MHz
    • Other frequencies within 2500-2690 MHz: -45 dBm/MHz
  • Transitional Region Emissions
    • ±5 MHz from block edge: +16 dBm/5 MHz

Active Antenna Systems (AAS)

  • Maximum TRP (Total Radiated Power) per cell
    • 53-60 dBm/(5 MHz) per cell
    • TRP accounts for the sum of power from all antennas.
  • Baseline Emissions
    • FDD DL, SDL, and synchronized TDD blocks: +5 dBm/MHz
    • Other frequencies within 2500-2690 MHz: -52 dBm/MHz
  • Transitional Region Emissions
    • ±5 MHz from block edge: +16 dBm/5 MHz

 

Please note that the ORS is a non-AAS system and we will focus only on the non-AAS limits in this page. Also, note that the EIRP must take into account the gain of the antenna and we must support an antenna with 17dB gain. So it means, the ORS must not exceed -62 dBm/MHz (-45-17) in the range 2500-2570MHz. Since all our experiments are using a FDD signal, and the real usage will be TDD, the limit is 1.5dB more. So the maximum allowed for a FDD signal is -60.5dBm/Mhz which is -48dB/18MHz. 

Measurement Protocol

The evaluation was conducted using a lab-verified ORS SDR board (PCB NO. F127, Band 38). A powerful signal (TM3.1) was transmitted from the SDR board and measured using a spectrum analyzer.

Measurement 1 (left edge, full power, no external filter)

  • Emission : Center frequency @2585MHz (FDD DL only), Bandwidth: 20MHz, TX power: 29dBm (tx_gain = 88, this is the maximum for our hardware).
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth (blue channel labeled L1).  
  • Result for UL baseline : When the signal center frequency is at 2585MHz, the left edge is at 2575MHz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -15.97dBm/18MHz,
    exceeding the required limit of -60.5 dBm/MHz (-48 dBm/18MHz)
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -9.4dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Measurement 1 bis (right edge, full power, no external filter)

  • Emission : Center frequency @2610MHz (FDD DL only), Bandwidth: 20MHz, TX power: 29dBm (tx_gain = 88, this is the maximum for our hardware).
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth (blue channel labeled L1).  
  • Result for UL baseline : When the signal center frequency is at 2610MHz, the left edge is at 2600Hz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -34.3dBm/18MHz,
    exceeding the required limit of -60.5 dBm/MHz (-48 dBm/18MHz)
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -33.86dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Measurement 2 (left edge, low power, no external filter)

  • Emission : Center frequency @2585MHz in FDD mode (DL only), Bandwidth 20MHz, TX power around 6dBm (tx_gain 65).
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth.
  • Result for UL baseline: When the signal center frequency is at 2585MHz, the left edge is at 2575MHz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -48.2dBm/18MHz, which is in the regulatory limit of -60.5 dBm/MHz (-48 dBm/18MHz) 
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -34.4dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Measurement 3 (left edge, full power, external filter A03)

  • Emission : Center frequency @2585MHz (FDD DL only), Bandwidth: 20MHz, TX power: 29dBm (tx_gain = 88). We add an external band pass filter called FT-26-40-NF-A03 (2580 - 2620MHz) .
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth (blue channel labeled L1).  
  • Result for UL baseline : When the signal center frequency is at 2585MHz, the left edge is at 2575MHz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -48.0dBm/18MHz, which is in the required limit of -60.5 dBm/MHz (-48 dBm/18MHz)
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -44.57dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Please note that the filter is degrading a bit the signal on the left (<the EVM is increased on the left). However, the speedtest with 1 UE is not showing any degradation in the bandwidth.

 

Measurement 4 (left edge, full power, external filter A04)

  • Emission : Center frequency @2585MHz (FDD DL only), Bandwidth: 20MHz, TX power: 29dBm (tx_gain = 88). We add an external band pass filter called FT-26-40-NF-A04 (2575 - 2620MHz) .
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth (blue channel labeled L1).  
  • Result for UL baseline : When the signal center frequency is at 2585MHz, the left edge is at 2575MHz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -47.0dBm/18MHz, which is just 1dB above the limit of -60.5 dBm/MHz (-48 dBm/18MHz)
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -44.57dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Please note that the filter is not degrading the signal on the left, the EVM is good on all the signal width.

Measurement 4-bis (left edge, full power minus 1dB, external filter A04)

  • Emission : Center frequency @2585MHz (FDD DL only), Bandwidth: 20MHz, TX power: 28dBm (tx_gain = 87). We add an external band pass filter called FT-26-40-NF-A04 (2575 - 2620MHz) .
  • Signal analyzer : Measure power of 2550MHz-2570MHz, 20MHz bandwidth (blue channel labeled L1).  
  • Result for UL baseline : When the signal center frequency is at 2585MHz, the left edge is at 2575MHz. As picture shows below, the average power in Block L1 from 2550 MHz to 2570MHz is -48.0dBm/18MHz, which is in the limit of -60.5 dBm/MHz (-48 dBm/18MHz)
  • Result for transitional region : As you can see in the marker zone, the power in the 5MHz transitional region is -44.57dBm/5MHz which is in the regulatory limit of -1dBm/5MHz.

Please note that the filter is not degrading the signal on the left, the EVM is good on all the signal width.

Measurement 5 (right edge)

  • Emission : Center frequency @2605MHz on FDD mode (DL only), Bandwidth 20MHz, TX power around maximum 29dBm.  
  • Signal analyzer : Measure power of 2620MHz-2640MHz, 20MHz bandwidth. 40dB attenuator before the input of signal analyzer.  
  • Result : On the signal analyzer, the center frequency is at 2610MHz, the right edge is at 2620MHz. As picture shows below, the average power in Block U1 from 2620 MHz to 2640MHz is -23.52dBm/18MHz (40dB ATT), considering that B38 will be in TDD, we will have 1.5dB less power (emission/reception ratio is 3.5/5), so we are in the regulatory limit of 4 dBm/MHz (17 dBm/18MHz) 

Conclusion and recommandations

Our ORS in B38 only meet the regulatory requirements with an additional external filter.

Instead of adding the external filter, to conform to EIRP standard, you can also use the ORS B38 with low power (under 6dBm).