# Tx output power and datarate measurement
**URL:** https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477
**Category:** General
**Created:** [April 11, 2025, 10:19pm UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477 "2025-04-11T22:19:09Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@nschae](https://community.morsemicro.com/u/nschae)
#### Post date: [April 11, 2025, 10:19pm UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/1 "2025-04-11T22:19:09Z")
Hi everyone,
I’m currently working with the MM6108-EKH08-05US-02 evaluation board (US band) and have a few questions:
1. **TX Power Configuration:** I noticed that the `mm_app_regdb.c` file defines `Max Tx EIRP (dBm)` values in the `s1g_channels_US` structure. Does modifying this value directly affect the actual transmit power of the device, or is there a separate mechanism or API to control the TX power within the firmware? Additionally, I am not sure the front-end module (FEM) on the board is capable of reaching the 36 dBm listed as the max EIRP. Could you clarify what the actual maximum transmit power is for this evaluation board?
2. **Continuous Transmission Mode:** For RF testing purposes, I need the device to transmit continuously. Is there a test mode or configuration that enables continuous wave (CW) transmission? If so, could you provide guidance on how to activate this mode, including any necessary commands or firmware modifications?
3. **PHY Data Rate Estimation:** I’m using the `iperf` example to evaluate system throughput, which works well. However, I would like to understand how to derive or estimate the PHY data rate from the `iperf` measurements for both TCP and UDP. Are there tools, logs, or methodologies available to assist with this?
Any insights or guidance on these topics would be greatly appreciated.
Best regards,
Nicolas
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### Author:  [@ajudge](https://community.morsemicro.com/u/ajudge)
#### Post date: [April 14, 2025, 2:13pm UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/2 "2025-04-14T14:13:39Z")
Hi Nicolas,
The `Max Tx EIRP` value sets the maximum transmission power for the specified channel in the region selected, these values reflect the regulatory limits for the region selected. If the hardware allowed for it, this value would be used to set the tx power. However, most modules are not capable of driving 30dBm or higher.
Maximum power is primarily dictated by the module design and a maximum power set in the board configuration file (BCF) such that the board passes required SEM limits for regulatory compliance.
Maximum power levels, per channel power backoffs, and per rate power levels are set in the BCF (eg `bcf_mf08651.mbin`) by the module manufacturer. In the case of this evaluation kit, that module manufacturer is us, and the module on board is limited to approximately 21dBm.
Quectel have a [new module](https://www.quectel.com/product/wi-fi-halow-fgh100m-h/) capable of 27dBm.
* * *
Unfortunately we don’t distribute this type of tooling publicly as that could allow non-compliant use of the radio. I will have to get back to you with any further information for getting access to this level of tooling.
* * *
Deriving the PHY rate from the iperf measurements could be tricky as there are a number of factors above the physical layer which impact the throughput - such as frame aggregation, network congestion and control, and so on. Instead, you would be better off examining the current selected MCS, bandwidth and guard setting for the transmitting device.
For the EKH08, the best you can acquire here is the rate statistics, with `mmwlan_get_rc_stats`. This returns a struct containing three lists. The first containing rate information (bandwidth, mcs index, guard interval), and the other two lists containing the total number and the successful packets sent. You can [derive the theoretical phy throughput](https://en.wikipedia.org/wiki/IEEE_802.11ah#Data_rates) from this rate information.
If you’re using one of our OpenWrt based evaluation kits as your Access Point, it is definitely easier to extract the current PHY rate directly from the OpenWrt user space tooling. `iwinfo wlan0 assoclist`.
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### Author:  [@ajudge](https://community.morsemicro.com/u/ajudge)
#### Post date: [April 19, 2025, 4:05pm UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/3 "2025-04-19T16:05:35Z")
Hi Nicolas,
To request access to the RF Test tools, please send an email to [support@morsemicro.com](mailto:support@morsemicro.com). Explain a little bit about who you are and why you need the tools. If accepted, you will then have to sign an NDA.
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### Author:  [@Shriram](https://community.morsemicro.com/u/Shriram)
#### Post date: [July 10, 2025, 2:09am UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/4 "2025-07-10T02:09:06Z")
I have a very similar question as Nicolas, just that I have an MM6108-EKH05v3 that seems to have an AW-HM593 module. How can I adjust/lower/back-off output power levels (US band) and generate a corresponding bcf file? Alternatively, would changing (lowering) the limits in the table in `mm_app_regdb.c` help my case? Thanks.
`
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### Author:  [@ajudge](https://community.morsemicro.com/u/ajudge)
#### Post date: [July 22, 2025, 2:26am UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/5 "2025-07-22T02:26:43Z")
If you’re just looking to lower the power outputs, you can modify the regdb to achieve this. There is also an API `mmwlan_override_max_tx_power()` to reduce power after `mmwlan_init`. The change to power level will only occur after switching channel - including on scan.
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### Author:  [@BarrettTwining](https://community.morsemicro.com/u/BarrettTwining)
#### Post date: [March 23, 2026, 11:21pm UTC](https://community.morsemicro.com/t/tx-output-power-and-datarate-measurement/477/6 "2026-03-23T23:21:57Z")
What is the minimum output power for the mm8108?