2km range test / distance measurement MCS value is fixed at 2 / MCS is locked at MCS 2

[tx5901]

Summary of TXW8301 Module 2km Long-Range Communication Test Results

1. Test Overview
   Module Used: TXW8301 (Wi-Fi HaLow)
   Target Distance: 2km
   Key Settings: MCS fixed at 2 (Long Range mode), Bandwidth 1MHz, Frequency 916MHz
2. Key Conclusion
   With the MCS value fixed at 2, the maximum distance for stable communication based on RSSI and SNR was confirmed to be approximately 700m. This falls significantly short of the 2km target.
3. Key Observations from Logs
   Severe Signal Degradation: As the distance increases, the RSSI drops below -80dBm and the SNR falls below 10dB, causing extreme signal instability.
   Surge in Packet Error Rate (PER): In weak signal areas, the PER spikes to 50%~100%, resulting in frequent Ping failures (100% packet loss).
   Connection Instability: Frequent disconnections and reconnections occur repeatedly due to Heartbeat failures.
   Drastic Drop in Actual Throughput: The txp (transmit power index) drops to 0. Furthermore, unlike the displayed estimated rate (est_rate), the actual Packet Reception Rate (PRR) is very low, causing a significant drop in effective data transfer speed.
4. Recommendations & Requests for Improvement
   Since guaranteeing 2km communication quality with the current fixed MCS 2 setting is difficult, please advise if the Auto Rate Fallback (MCS adaptation) feature can be enabled or optimized.
   Physical antenna gain improvement or TX Power (transmit output) settings need to be re-evaluated.
   MAC layer parameter adjustments, such as increasing the ACK Timeout value for long-range environments, appear necessary.

[tx5901]

Summary of Wi-Fi HaLow 2km Test MCS Fixed Settings

■ Overview
During the Wi-Fi HaLow (802.11ah) 2km long-range test using the TXW8301 chipset,
the MCS (Modulation and Coding Scheme) value is fixed at 2 for the test execution.

■ Software Version

• TXW8301_FMAC: v2.4.1.5-43933
• TXW8301_WNB: v2.4.1.3-43933

■ Test Settings

[Basic Parameters for 2km Mode]
2km mode: ack_tmo=300, bss_bw=1, tx_mcs=0

[Actual Test MCS Values]

• Fixed MCS: MCS 2
• Bandwidth: 1 MHz (BW=1)
• Frequency: 916.0 MHz
• ACK Timeout: 300ms

■ Test Log Example

[Confirmed in AP Log]
STA1: ce:4f:26:8f:aa:88 V2.4
tx1: mcs=2 snr=40 data=0KB(0kbps) per=0
rx1: mcs=2 evm(avg:std)=-29:1 rssi=-7 data=0KB(0kbps)

[Reasons for Using MCS 2]

1. Long-Range Communication Optimization: MCS 2 is a relatively low modulation
   scheme, which helps maintain a stable connection during 2km long-range
   communication.
2. Enhanced Robustness: Ensures communication even in noisy environments by
   securing a high SNR margin.
3. Test Standardization: Enables consistent performance comparison across
   different distances under uniform test conditions.

■ Related Configuration Commands

Settings confirmed in the log:
AT+TX_MCS=0 # MCS auto mode (actually uses MCS 2 internally)
AT+BSS_BW=1 # Set bandwidth to 1MHz
AT+ACK_TO=300 # Set ACK timeout to 300ms

■ Notes

• Although tx_mcs=0 is set in the source code, MCS 2 is forcibly applied
  internally when in 2km mode.
• This is considered a firmware-level setting designed to ensure the reliability
  of long-range tests.
• MCS 2 utilizes the QPSK modulation scheme and is optimized for long-range
  and low-power environments.

[tx5120]

It seems that on the test hardware you are using, 700m has reached its limit. Consider checking whether the transmission power or reception sensitivity is normal? Have you tried using MCS automatic adjustment? Can you achieve a longer distance?

[tx5901]

@tx5120 1. How can I configure the MCS auto-adjustment function?
2. I would like to set it to a fixed value manually; is there a way to do that?

[tx5901]

-------------------<CR><LF>
[561974]LMAC STATUS:<CR><LF>
local: ce:4f:26:8f:aa:88 AID= 0 mode= 0(0/1:STA;2:AP)<CR><LF>
freq= 916.0 bw=1 bgr=-106 dc=0:0(5:44) <CR><LF>
chn: 908.0 916.0 924.0 <CR><LF>
bgr: -107 -107 -107 <CR><LF>
buf: free=65 tq=0 sq=0 <CR><LF>
irq: ac=43 bkn=0 bo(rts:frm)=0:0:0:0:43 to(rts:frm)=0:0 rx=52<CR><LF>
tx : cnt=43 dly=0:0ms est_rate=900kbps txp=0 fail=0 drop=0 <CR><LF>
rx : cnt=52 bus=1ms<CR><LF>
cca: st12= 0:0 mid1224= 0:0:0:0<CR><LF>
chip-temperature:37, vcc:3.37, vdd13b:1.35, vdd13c:1.34<CR><LF>
sta_list: no sta<CR><LF>
<CR><LF>
<ESC>[563415]ieee80211_sta_select_bss:24::by SSID find hgic_ah_test [50:2e:91:d2:c4:c9] at channel 2<CR><LF>
<ESC>[563424]vif1 state WPA_SCANNING -> WPA_AUTHENTICATING<CR><LF>
[563434]Invalid group cipher (0).<CR><LF>
[563435]vif1 state WPA_AUTHENTICATING -> WPA_ASSOCIATING<CR><LF>
<ESC>[564341]ieee80211_sta_assoc_timeout:53::connect to ap 50:2e:91:d2:c4:c9 timeout, disable it!<CR><LF>
<ESC>[564349]ieee80211_sta_disconnect LR= 0x20048df4. 50:2e:91:d2:c4:c9<CR><LF>
[564354]lmac set GTK: cmd=1 addr=50:2e:91:d2:c4:c9 cipher= 0x0 flags= 0x0 keyidx= 0 keylen= 0<CR><LF>
[564363]del_STA: addr=50:2e:91:d2:c4:c9<CR><LF>
[564366]stamap=0x0<CR><LF>
[564368]sleepmap=0x0<CR><LF>
[564370]vif1 state WPA_ASSOCIATING -> WPA_DISCONNECTED<CR><LF>
[564375]vif1 state WPA_DISCONNECTED -> WPA_AUTHENTICATING<CR><LF>
[564380]vif1 state WPA_AUTHENTICATING -> WPA_SCANNING<CR><LF>

"I am currently testing the connection between a Morse Micro AP and a Taixin product. The next step appears to be obtaining an IP address, but it is not being assigned. I would like to know how to proceed with this."