Jetson TX1 WIFI power abnormal

Autonomous Machines Jetson & Embedded Systems Jetson TX1
#1

Would you please help to answer below questions for Jetson TX1 WIFI?

1.We have two antenna ports from Jetson TX1,do the two ports have same power and sensitivity,We have met problem when antenna test that 1 ant port can output about 17db power ,but another only 3db?
2.Do you have the test report for TX1 WIFI conductive status?

Br.liuchang

#2

Hi, WIFI on TX1 passed certification, for power and other related info please refer to this topic: https://devtalk.nvidia.com/default/topic/1025396/jetson-tx2/transmission-power-of-the-tx2-wifi-module/, and this doc in download zone https://developer.nvidia.com/embedded/dlc/Jetson-TX1-OEM-Wireless-Compliance-Guide

#3

I’m sorry that I didn’t find information for transmission power in this documents, only recommediation for anntenn gain here ,is there other docuement that describe about this case ?

And what is the difference between the two antenna ports as we get different transmission power from the two ports ,one is 17,one is only 3 ,thanks!

#4

Please check this topic: https://devtalk.nvidia.com/default/topic/1026436, there should be no difference between two antennas.

#5

Thanks very much for your reply,and what confused me is that I tested the WIFI antenna seperately from antenna,one port output is 17db,it is normal ,and another is only 3.

And BCM4354 support MIMO and BT,may the default setting for the antenna ports defination is :
1 for BT ,and another for WIFI?

Br.liuchang

#6

Hi liuchang,

  1. What is the wifi channel used
  2. what is the usecase done (is BT on/off, connected/idle, scanning ?)
  3. what is the data rate used
#7

Thanks for you quick feedback ,and we found the reason now.
That is because that the default mode for the BCM4354 now is one port for BT ,another for WIFI.

And would you please help to check that how can I set the IC default mode to WIFI MIMO mode? Thanks a lot !

#8

Hi liuchang,

Could you provide more detail how do you know one port is for BT and another is for WIFI?

#9

Sorry that I have double confirmed that can’t make sure that one is for BT ,and another is for WIFI ,but result confused us is that the power from two ports have 14db difference ,do you have any reason suggest?

and for the question：
1.WIFI channel is 1
2.BT OFF
3.2.4G

#10

Hi liuchang,

For question 2, any other detail? What is the case when you do measurement? Do you connect anything or just idle?

#11

We tested by connecting to CMW500

#12

Hi liuchang,

  1. With BT off, there is no antenna sharing across wifi and BT. If BT is ON, antenna0 will be shared between BT and wifi transmission.

  2. data rate will keep varying - depending on the wireless environment/congestion.
    a. For MIMO condition, power on both cores is set to be same
    b. Tx power is dependent on the data rate of the transmission. So if power measurement is happening in open-air, it is likely that there is data rate fluctuation causing power measurement fluctuation.

Thus, please describe more about your test environment(I mean use case, client numbers, indoor or not …).

#13