RBK353 Increase bandwidth up to 50% by repositioning router and satellites.
RBR350, in AP mode + 2 satellites RBS350
Firmware version: V4.4.1.29_3.10.80 Hardware version RBR350 Hardware Type ORBI
The problem: When I first connected up the Orbi router (RBR350) and satellites (RBK350) and measured the bandwidth I got a pultry 248 Mbps in one direction and 307 Mbps in the other direction when I was expecting close to the specified (theoretical) maximum of 1200Mbps.
Bandwidth measurement: I am not using any test based on speedtest.net because that is dependendent upon the QoS provided by my ISP and a whole load of factors outside my control. The physical connectivity is:
+----------+ 1Gbps +-----------+ WiFi 6 ax +--------+ 1GBps +----------+
| server A |---------| satellite |- - - - - - -| router |---------| server B |
+----------+ Wired | | | | Wired +----------+
| | | |
+----------+ | | | | +----------+
| server C |---------| satellite | | router |---------| server D |
+----------+ +-----------+ +--------+ +----------+
I transfer a 1GiB file using the linux 'dd' command, from server A to server B, and then repeat in the reverse direction:
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 34.5451 s, 31.1 MB/s
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 27.9948 s, 38.4 MB/s
I run equivalent tests between server A and server C, and also server B and server D to confirm the 1GBps wired bandwidth.
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 9.25473 s, 116 MB/s
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 9.81479 s, 109 MB/s
giving 928 Mbps and 872Mbps. Thus I never expect to get the 1200Mbps theoretical, but I was expecting something close to 850Mbps.
I wrap the "dd" commands into scripts, repeat multiple times, take the average of 4 or more measurements, run between many combinations of server pairs (A-B,A-D,C-B,C-D) and so on.
The results: Given the initial results of 248 Mbps and 307 Mbps, I very quickly moved the satellite from desklevel adjacent to the metal server enclosures and a brick wall. I then played with moving both the router and satellite to different nearby shelving, changing the orientation and changing every setup setting available. As I changed each setting (like turning off AX, reducing transmit power, connecting/disconnecting the second satellite) I set a somewhat cryptic value (like third [shelf], "+s2" [with 2nd satellite]) to a variable that was recorded in the results. I was also careful to eliminate outside factors, like when scheduled backups were in progress. I observed consideredable variation in bandwidth, even when not changing anything. I expected a period of time (20 mins) for beamforming. I performed multiple resets of the router and satellites, but laterly avoided doing so because of the time wasted with no observable gain. To date, I have recorded the results of over 15,000 1GiB file transfers. The position of both the router and the satellite have by far the most dominant effect on bandwidth. Although there are 6 degrees of freedom of positioning (3 axis + 3 rotations), I quickly settled on moving each (router, satellite) along one axis, the distance from the front of the shelf.
Orbi bandwidth measurements ranked according to highest average
for all positions and settings
(bandwidth averaged over 4 or more 1GB file transfers in each direction)
router satellite Date Min Average Max Spread
cm setup cm info Mbps Mbps Mbps Mbps
---------- ---------- ------------------- ------- ------- ------- -------
12.0 third 2.0 low 2024-03-22 12:00:58 612.000 646.000 684.800 72.800 1
12.0 third 2.0 low 2024-03-22 12:03:00 606.400 642.500 680.000 73.600 2
12.0 third 2.0 low 2024-03-23 14:02:15 609.600 642.400 683.200 73.600 3
12.0 third 2.0 low 2024-03-24 17:02:43 607.200 639.400 693.600 86.400 4
12.0 Vs2G4 2.0 low 2024-03-24 17:16:23 582.400 639.300 693.600 111.200 5
8.0 third 2.0 low 2024-03-22 11:06:38 577.600 638.800 694.400 116.800 6
9.0 third 6.0 low 2024-03-21 15:56:43 508.000 638.400 708.800 200.800 7
8.0 third 2.0 low 2024-03-22 11:08:39 596.000 637.900 675.200 79.200 8
0.0 third 3.0 low 2024-03-21 10:23:04 604.000 637.886 668.800 64.800 9
12.0 third 3.0 low 2024-03-21 12:41:35 604.800 637.657 691.200 86.400 10
12.0 third 6.0 low 2024-03-21 16:25:04 601.600 637.486 692.800 91.200 11
12.0 third 2.0 low 2024-03-23 14:00:12 592.800 637.200 685.600 92.800 12
12.0 Vs2G4 2.0 +s2 2024-03-25 10:09:45 592.800 636.900 680.800 88.000 13
12.2 third 2.2 low 2024-03-23 20:52:58 602.400 636.000 676.000 73.600 14
11.9 third 1.9 low 2024-03-24 11:40:50 573.600 635.800 680.000 106.400 15
12.0 short 2.0 low 2024-03-24 16:52:34 522.400 635.200 697.600 175.200 16
10.0 third 4.0 low 2024-03-22 14:15:33 605.600 635.000 680.000 74.400 17
9.0 third 9.0 low 2024-03-21 19:59:54 599.200 633.829 693.600 94.400 18
12.0 third 2.0 low 2024-03-24 17:00:40 579.200 633.800 668.800 89.600 19
...
17.7 third 3.0 low 2024-03-21 14:01:14 424.000 446.400 478.400 54.400 801
15.0 third 3.0 low 2024-03-21 13:16:36 329.600 445.657 472.800 143.200 802
17.7 third 0.0 low 2024-03-20 23:32:28 404.000 443.314 457.600 53.600 803
17.7 third 0.0 low 2024-03-20 23:11:10 373.600 441.771 494.400 120.800 804
15.0 third 0.0 low 2024-03-20 22:09:12 380.000 441.200 496.800 116.800 805
12.0 25% 2.0 low 2024-03-24 14:38:35 177.600 440.600 535.200 357.600 806
17.7 third 0.0 low 2024-03-20 23:05:44 396.000 440.286 480.800 84.800 807
10.0 third 0.0 low 2024-03-22 20:26:44 427.200 439.900 472.000 44.800 808
17.7 third 0.0 low 2024-03-20 23:21:37 394.400 438.971 477.600 83.200 809
15.0 third 3.0 low 2024-03-21 13:00:49 402.400 438.000 461.600 59.200 810
17.7 third 0.0 low 2024-03-20 23:27:05 398.400 435.886 457.600 59.200 811
3.0 third 0.0 low 2024-03-20 20:11:27 381.600 434.571 520.800 139.200 812
3.0 third 0.0 low 2024-03-20 20:05:57 204.800 427.714 496.000 291.200 813
10.0 third 0.0 low 2024-03-22 20:23:54 393.600 423.600 440.800 47.200 814
Top ranking of bandwidth in different positions:
----------+---------------------------------------------------------
Satellite | Router position (from edge of shelf) cm
position | 0.0 3.0 6.0 9.0 12.0 15.0 18.0
cm +---------------------------------------------------------
0.0 | 465 780 295 54 33 750 711
3.0 | 9 690 212 6 1 789 299
6.0 | 305 574 391 7 11 157 50
9.0 | 411 191 698 18 727 57 202
12.0 | 493
Orbi bandwidth measurements ranked according to highest average
for positions within a few mm of optimal
(bandwidth averaged over 4 or more 1GB file transfers in each direction)
router satellite Date Min Average Max Spread
cm setup cm info Mbps Mbps Mbps Mbps
---------- -------- ------------------- ------- ------- ------- -------
12.0 third 2.0 low 2024-03-22 12:00:58 612.000 646.000 684.800 72.800 1
12.0 third 2.0 low 2024-03-22 12:03:00 606.400 642.500 680.000 73.600 2
12.0 third 2.0 low 2024-03-23 14:02:15 609.600 642.400 683.200 73.600 3
12.0 third 2.0 low 2024-03-24 17:02:43 607.200 639.400 693.600 86.400 4
12.0 Vs2G4 2.0 low 2024-03-24 17:16:23 582.400 639.300 693.600 111.200 5
12.0 third 2.0 low 2024-03-23 14:00:12 592.800 637.200 685.600 92.800 6
12.0 Vs2G4 2.0 +s2 2024-03-25 10:09:45 592.800 636.900 680.800 88.000 7
12.2 third 2.2 low 2024-03-23 20:52:58 602.400 636.000 676.000 73.600 8
11.9 third 1.9 low 2024-03-24 11:40:50 573.600 635.800 680.000 106.400 9
12.0 short 2.0 low 2024-03-24 16:52:34 522.400 635.200 697.600 175.200 10
12.0 third 2.0 low 2024-03-24 17:00:40 579.200 633.800 668.800 89.600 11
12.2 third 1.8 low 2024-03-23 19:38:02 513.600 633.700 699.200 185.600 12
12.0 2.4/4 2.0 low 2024-03-24 14:17:57 575.200 632.500 686.400 111.200 13
11.8 third 1.8 low 2024-03-23 19:09:41 545.600 631.800 677.600 132.000 14
12.0 Vs2G4 2.0 +s2 2024-03-24 21:23:52 518.400 631.500 696.000 177.600 15
12.0 third 2.0 low 2024-03-24 14:04:51 547.200 631.400 676.000 128.800 16
12.0 third 2.0 low 2024-03-23 23:16:06 603.200 630.900 668.000 64.800 17
12.0 Vs2G4 2.0 +s2 2024-03-25 10:07:42 592.000 630.000 673.600 81.600 18
12.2 third 1.8 low 2024-03-23 19:35:59 495.200 629.500 690.400 195.200 19
...
11.8 third 2.2 low 2024-03-23 20:22:50 465.600 563.800 660.000 194.400 231
12.0 no_ax 2.0 low 2024-03-24 16:09:57 434.400 559.100 605.600 171.200 232
12.0 third 2.0 low 2024-03-23 23:20:40 287.200 555.400 684.000 396.800 233
12.0 third 2.0 low 2024-03-23 23:27:50 292.000 554.300 694.400 402.400 234
12.0 Vs2G4 2.0 low 2024-03-24 19:18:56 418.400 554.000 612.800 194.400 235
12.0 no_ax 2.0 low 2024-03-24 16:14:34 445.600 548.200 627.200 181.600 236
12.0 third 2.0 low 2024-03-22 22:47:46 440.800 545.000 597.600 156.800 237
12.0 third 2.0 low 2024-03-23 23:25:23 404.000 536.200 657.600 253.600 238
12.0 third 2.0 low 2024-03-22 22:40:53 428.000 531.600 602.400 174.400 239
12.1 third 1.9 low 2024-03-24 12:06:39 217.600 514.100 694.400 476.800 240
Top ranking of bandwidth in different positions:
----------+-----------------------------------------
Satellite | Router position (from edge of shelf) cm
position | 11.8 11.9 12.0 12.1 12.2
cm +-----------------------------------------
1.8 | 14 24 12
1.9 | 9 65 78
2.0 | 26 42 1 32 55
2.1 | 32 43 84
2.2 | 64 56 8
Conclusion: I increased the backhaul bandwidth by about 50% purely by adjusting the positions of the router and satellite with 1mm precision.
Re: RBK353 Increase bandwidth up to 50% by repositioning router and satellites.
Good to know.
What is the size of your home? Sq Ft? What is the distance between the router 📡 and satellite(s)🛰️? 30 feet or more is recommended in between RBR 📡 and RBS 🛰️ to begin with depending upon building materials when wired or wirelessly connected. https://kb.netgear.com/31029/Where-should-I-place-my-Orbi-satellite 🛰
Re: RBK353 Increase bandwidth up to 50% by repositioning router and satellites.
Distance between router and satellite about 5m (15ft) through stair case wood and a single skin brick wall.
Floor area approx 80m^2 (860 sq ft). But this is surely irrelevant because I am not using the WiFi to connect to mobile and IoT devices. The only thing I was interested in and tested was the backhaul bandwidth.
I'm puzzled as to why the recommendation is more than 10m (30ft) because surely the further away, the weaker the signal strength and presumably lower bandwidth.
I'm puzzled as to why the recommendation is more than 10m (30ft) because surely the further away, the weaker the signal strength and presumably lower bandwidth.
This recommendation is based on the premise that the point of purchasing a mesh WiFi system is to provide WiFi coverage. (Which does not appear to be relevant to your situation.)
Imagine if WiFi units were 1 ft. apart. That would increase the area provided with strong WiFi signals by so little that it might not be measurable. Also, devices might get into a pattern of switching back and forth when (temporarily) they sense that one unit is stronger than the other. If the units were 50 ft. apart, the areas of good coverage would probably not overlap at all, giving an increase of 100%, but the backhaul link would not function. At least 10 ft. of separation creates a significant increase. The "sweet spot" appears to be about 30 ft. (balancing increased coverage against strength of backhaul signal).
