Ubiquiti LTU | Field tests | Stress test | Batna24.com
arrow_drop_downUSA (US) / GBP / Prices without VAT

Ubiquiti LTU | part 2 | professional field tests

A word of introduction

New solution from Ubiquiti Networks is gaining more and more recognition among wireless network followers, and LTU technology becomes more and more popular. In previous publications we have already had a chance to familiarize ourselves with the whole range of LTU products and performed preliminary tests of this solution (desktop). This time we will present you the results of professional tests performed in the field. On this basis, we will draw conclusions how efficient (packet performance) are the devices from Ubiquiti Inc. based on LTU protocol. All the obtained results will be available in the further part of this article. We invite you to read it.

Packet efficiency above all else!

Just as a reminder. The main idea of developing LTU protocol (LTU technology) was to increase network efficiency for PTMP connections! The devices are to work perfectly in harsh environments, where the noise is very high. Ubiquiti Inc. developed new LTU protocol to connect a very large number of clients, while maintaining a very high wireless network performance. All this is possible thanks to several factors:
  • 21.2bps per Hz (spectral efficiency)
  • over 2 million packets per second
  • 4096QAM modulation

Ubiquiti LTU - long distance test

Right. Enough theory! Let's move on to the performance offered by LTU technology. We performed tests for distances above 4.5km (LTU Pro) and below 2km (LTU Lite)
Stress test assumptions for LTU:
  1. CPE end in range (client cpe) LoS over 4.5km with minimum 64QAMmodulation
  2. Minimum CP E performance with 20MHz channel width at 64QAM Dowload 32Mbps/Upload 7Mbps
  3. Sector capacity at 20MHz channel width minimum 120Mbps/24Mbps
  4. Measurement of CPE and "sector" performance according to EtherSAM standards (asymmetric traffic) for traffic with IMIX characteristics (Internet MIX according to IETF RFC 6985 "IMIX Genome: Specification of Variable Packet Sizes for Additional Testing") according to parameters presented in the table below.
  5. Thedistribution of channels on sectors (4x90 degrees) with no spacing in frequencies. That is, sectors A and C center frequency 5700MHz, and sectors B and D center frequency 5680MHz.
  6. Tests performed in L3layer
  7. Packet loss at the level of 0,03%.
  8. Maximum packet time 50ms
  9. Maximum packet jitter 40ms
  10. Maximum instantaneous decrease of preset (minimum) speed to 95%.
  11. EtherSAM test duration 2 hours

Hardware used for testing

rl elements hg3 Kliknij aby powiększyć!
  • VeeEx VePAL TX300S meter with software version 3.5.13 for platform and 3.5.7 for module
Kliknij aby powiększyć!

The structure of packets used in the test

No.

Bundle length [B].

Number of packets (ratio)

Number of packets for traffic (D/U) 32Mbps/7Mbps

Number of packets for traffic (D/U) 120Mbps/24Mbps

1

68

7

D: 11507 ppsU
: 2517 pps

D: 43151 ppsU
: 8630 p
ps

2

595

4

3

1518

1

Total one set of packets

2181 bytes

12 packages

(D - download, downloading to CPE; U-upload, uploading from CPE)
packet frame Kliknij aby powiększyć!

2km test results

Now that we know the specifics of our tests, let's move on to the results obtained. First, we will take a closer look at the results we obtained during the 2-hour test with the EtherSAM meter.

Test results for one CPE(LTU Pro) at a distance of about 2km and frequency of 6100MHz. The height of the CPE is about 5m above sea level, LoS.
4xIMIX Kliknij aby powiększyć!
We performed further tests with the VeEx VePal TX300S meter at a set throughput of Download 130Mbps, Upload 28Mbps with the IMIX* characteristics described in the table above.
"Local Results" -> uploading from CPE "
Remote Results" -> downloading to CPE.
Network traffic characteristics used for measuring network device performance described in RFC6985 as Internet Mix (IMIX) or other characteristics specified in the manufacturer's documentation.


vsam_test1 Kliknij aby powiększyć!
vsam_test2 Kliknij aby powiększyć!
vsam_test3 Kliknij aby powiększyć!

5km test results

After successful testing at distances under 2km, we decided to increase the distance to almost 5km and changed the CPE client device to the Ubiquiti LTU-Pro. What's more! We performed tests at longer distances using different channel widths (20/30/40/50MHz) and different software versions: 2.1-BETA4 and 2.1-BETA5.

Distance and Fresnel Zone

Fresnel zone Kliknij aby powiększyć!

Ubiquiti Networks LTU throughput test results

As I mentioned earlier, we ran the tests for different software versions, different channel widths, and with a variable"Performance Boost" parameter. Below, the results from the obtained Download and Upload speeds.

Distance
 4.88km

20MHz

30MHz

40MHz

50MHz

2.1-BETA4

2.1-BETA5

2.1-BETA4

2.1-BETA5

2.1-BETA4

2.1-BETA5

2.1-BETA4

2.1-BETA5

Performance Boost

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

Download [Mbps]

134.7

137.8

137.2

137.9

183.0

204.8

183.5

205.4

187.1

268.5

181.8

270.2

211.3

246.8

188.3

248.5

Upload [Mbps]

25.2

26.3

26.4

25.7

42.0

41.8

42.0

40.9

55.7

54.7

55.8

54.6

48.1

47.3

47.6

46.5

Duplex
 Download
 Upload
  [Mbps]

133.9
 25.2

135.2
 24.4

136.5
 24.3

135.3
 23.7

183.8
 40.8

203.1
 38.4

180.5
 40.8

204.2
 40.3

186.6
 52.8

267.7
 52.7

179.4
 53.8

264.9
 52.8

209.1
 47.2

228.7
 41.3

198.8
 46.2

272.9
 45.1


Based on the above results, the conclusions are almost self-evident. The results for 50 MHz are surprisingly low, compared to those for 40 MHz! This is due to lower modulations that the devices have negotiated for this channel width, so it is not recommended to set large channel widths for distant links, unless, of course, the device works as a radio link.
The most optimal is to use 30MHz and we strongly recommend using this channel width. It's definitely a compromise between the effective range and the total capacity of a given sector (transmitter).
Below we present the obtained results. Let's focus only on the tests in the 30 and 50MHz channel widths, since we care about them the most.

Ubiquiti LTU - Results 30MHz 2.1-BETA4

.

Kliknij aby powiększyć!

Ubiquiti LTU - Results 30MHz 2.1-BETA5

Ubiquiti LTU - Results 30MHz 2.1-BETA5 Kliknij aby powiększyć!

Ubiquiti LTU - 50MHz 2.1-BETA4 results

Ubiquiti LTU - 50MHz 2.1-BETA4 results Kliknij aby powiększyć!

Ubiquiti LTU - 50MHz 2.1-BETA5 results

Ubiquiti LTU - 50MHz 2.1-BETA5 results Kliknij aby powiększyć!

Version 2.1.0-BETA5

As can be seen in the above graphics, software version 2.1.-BETA5 does not bring groundbreaking changes in both parameters and throughput. On the other hand, it contains significant improvements in the stability of connections and completely changes the appearance of the graphical interface, so that the GUI works much faster and smoother. Below we present some screenshots of the new Ubiquiti LTU GUI.
LTU gui

Conclusions

1. software up to version 2.0.6 (inclusive) and BETA versions up to 2.1-BETA3 (inclusive) caused very high stability, performance and interference problems.

2. Enabling the"Performance Boost" function results in increased throughput (maximum band saturation values), at the expense of the number of CPEs the base station can support.

3. Until software versions 2.0.7 and 2.1-BETA4 (inclusive) the split frequency function did not cause any increase in throughput

4. Any client CP E that is not used for a longer period of time (sometimes after only 2 minutes) goes to sleep. In the case of download/upload on software up to 2.0.7 and 2.1-BETA4 (inclusive), with full available bandwidth, this caused a stair-stepping effect and of course also involved an increase in modulation. This effect caused the dormant CPE to lose packets at the very beginning (due to buffering and error correction, this is not visible without advanced meters). Software 2.1-BETA5 significantly improves this unfavorable effect and then the problem is no longer troublesome. Tests with the CPE "awake" showed no packet loss.
LTU Steps
LTU packet lost
5. all Ubiquiti LTU devices, after exceeding the operating frequency of 6000MHz, experience a gradual deterioration of wireless parameters. The difference between the performance of devices operating at 5500MHz and 6200MHz can reach up to 10dBm! Additionally, all CPEs, on the second receiving channel, are noticing increasing difference in comparison to the first receiving channel. As the frequency increases, the parameters of the base station reception deteriorate, which can be seen on the screens below (distance of 4.88km). We have tested it on various combinations of antennas, including Ubiquiti AM-5AC22-45 and Ubiquiti AP-5AC-90-HD.
LTU signals
6. the 50MHz width at 4.88km is too wide to obtain the same modulations as for narrower channels.

Summary

As a quick recap. When using solutions Ubiquiti LTU you need to pay special attention to the fact that the GPS antenna is sensitive to interference from metal structures. To properly communicate with a large number of satellites, it needs good placement, otherwise we will have problems with gps synchronization. It should also be remembered that an unused CPE "goes to sleep", which limits the range of packet exchange for maintaining the connection. Sudden activation of transmission causes that the device needs "time" to negotiate appropriate bandwidth for itself on the sector. This results in the above mentioned "stairs" at the very beginning of the speed graphs.
One thing is certain.The Ubiquiti LTU series is distinguished by very high packet throughput! And the RoadMap of new features itself makes us optimistic that there will be further changes soon (in future versions of the software), which will increase throughput and operation in nLoS installations. Add to that strong encryption of wireless transmission and "Performance Boost" mode and we get a very efficient solution that will work in all conditions. And above all, Ubiquiti Networks LTU network devices provide customers with a stable service from the top shelf.

Authors:
Wojciech Repinski
Leszek Błaszczyk




Choose a different country or region to shop in the language that suits you
Our site uses cookies (so-called "cookies"). You can find more about these files, as well as about how we process your personal data, in our privacy policy.
You are on page for country / region:

Please select a different country or region to shop in a language that suits you.