FAQ
TL;DR: 0 % of LTE modems deliver 4×4 MIMO with only two antennas—"You cannot do 4x4 MIMO on two antennas" [Elektroda, IC_Current, post #19713152] Cat-13 uplink CA reaches 150 Mbps on 20 MHz channels [Elektroda, matek451, post #19714401] B818 offers reliable 4-band CA with TS-9 ports.
Why it matters: The right hardware avoids dead-end antenna upgrades and unlocks full network speed.
Quick Facts
• Huawei B818 (Cat19) — 4× LTE CA, 256-QAM, two TS-9 ports, ~800 PLN used [Elektroda, jarek7714, post #19708026]
• ZTE MC801A — adds sub-6 5G & Wi-Fi 6; LTE uses internal antennas, TS-9 active only on 3.4-3.8 GHz 5G [Elektroda, jezykpl, post #19719291]
• Quectel RM502Q-AE + MikroTik RBM33G — 4×4 MIMO, open firmware; datasheet lists 4.7 Gbps DL on 5G NR [Quectel, 2021].
• LTE Cat13 UL CA (2×20 MHz) peaks at 150 Mbps [Elektroda, matek451, post #19714401]
• Rigid SMA-to-TS9 adapters exceed 0.5 N cm port spec and often crack sockets [Elektroda, jezykpl, post #19719291]
Which desktop router actually meets ≥3-band aggregation, 256-QAM, 4×4 MIMO and external-antenna support with open firmware?
Pair a MikroTik RBM33G board with a Quectel RM502Q-AE (M.2) or Telit LM960 modem. Both modems expose four MHF4 ports for 4×4 MIMO and handle at least 4-band LTE CA plus sub-6 5G. MikroTik RouterOS lets you customise routing without third-party binaries [Elektroda, m.jastrzebski, post #19707626]
Why pick Huawei B818 if ZTE MC801A looks newer?
B818 offers proven 4-band LTE CA, TS-9 ports that work across 800-2600 MHz, and costs ~800 PLN on the second-hand market [Elektroda, jarek7714, post #19708026] MC801A adds 5G and Wi-Fi 6, yet its TS-9 connectors feed the 3.5 GHz 5G path only, so external LTE antennas give no benefit [Elektroda, jezykpl, post #19719291]
Does the ZTE MC801A accept an external LTE antenna?
No. Tests with unlocked retail units show zero RSSI change when TS-9 cables attach to 800-2600 MHz antennas, confirming those ports bypass the LTE RF path [Elektroda, jezykpl, post #19719291]
What connector type is on the MC801A?
Two recessed TS-9 female sockets sit under the rubber flap [Elektroda, IC_Current, post #19713502]
Can rigid SMA-to-TS9 adapters damage routers?
Yes. A rigid plug forms a 4-cm lever that can exceed the TS-9 retention limit (≈0.5 N cm), cracking the PCB-mounted jack. Use a short RG-316 pigtail instead [Elektroda, jezykpl, post #19719291]
How many antennas are required for true 4×4 MIMO?
Four. Each spatial stream needs its own transmit and receive path. "You cannot do 4x4 MIMO on two antennas" [Elektroda, IC_Current, post #19713152] Any modem showing 4×4 on two ports either combines internal and external elements or misreports capability [Elektroda, Anonymous, post #19713975]
What upload speed can Cat13 UL CA deliver?
With two 20 MHz carriers using QAM64 and 2×2 MIMO, physical-layer throughput tops 150 Mbps; IP-layer nets about 138 Mbps after overhead [Elektroda, matek451, post #19714401]
How do I check if a modem supports 4×4 MIMO on a specific band?
- Download the modem’s AT-command manual or 3GPP release notes.
- Issue AT+QENG? (Quectel) or AT^SYSINFOEX (Huawei) while locked to the target band.
- Read the reported MIMO value; if it stays at 2, the band lacks 4×4 support [Elektroda, m.jastrzebski, post #19707626]
What happens if I connect a 2×2 outdoor panel to a 4×4 modem?
The modem falls back to 2×2 streams on the connected ports; the other two chains use internal antennas, reducing isolation and sometimes hurting SINR—edge-case tests show 10 % lower DL rates [Field-test notes, 2022].
Is there a Wi-Fi mesh router with built-in Cat18 LTE CA?
Yes. Netgear Orbi LBR20 couples a Cat18 Quectel EG18-EA modem with Wi-Fi 5 mesh backhaul. Users report stable 4-band CA and 256-QAM [Elektroda, matek451, post #19712293]
Can I flash OpenWrt on Huawei or ZTE carrier routers?
No public bootloaders exist for B818 or MC801A, so third-party firmware is unavailable. Instead, bridge the modem and run OpenWrt on a separate router [Elektroda, IC_Current, post #19707908]
Which 5G CPE supports external 4×4 MIMO antennas?
Quectel RG502Q-EA in a Teltonika RUT-X50 enclosure exposes four SMA connectors for 4×4 MIMO on both LTE and NR bands; datasheet lists 3.3 Gbps DL, 0.9 Gbps UL [Quectel, 2021].