July 9, 2010 at 01:14Testing a wifi link based on Ubiquiti NanoStation M2 equipment
There was a need to test in detail a couple of NanoStation M2 for the possibility of their use for organizing a link for 5 km.
Since this is not our first test and the circuit has already been tested for performance in the first test last summer, I will not describe the technique in detail.
The points are located in close proximity, the signal level is wonderful:
MIMO mode is felt in the equipment, the speed pleased
The speed failure was formed when a friend was between two antennas.
The average simplex channel speed was 42 Mbps (left).
In duplex mode, the points gave 26 Mbit / s in each direction and 52 Mbit / s in total (right).
Also, 10 pings were sent with a length of 1024, 16384 and 65000 bytes, the results are as follows:
1024 - Minimum = 1 ms, Maximum = 2 ms, Average = 1 ms
16384 - Minimum = 8 ms, Maximum = 11 ms, Average = 8 ms
65000 - Minimum = 19ms, Maximum = 28ms, Average = 22ms
At the maximum output signal level (28 dBm) at the receiving side, -61 dBm was obtained.
According to the test results, the situation is as follows:
In simplex mode, the average speed is 12.7 Mbit / s - in duplex 5.25 for transmission and 6.37 for reception .
A test was also conducted when transmitting IPTV real-time traffic (RTP). The intensity of the generated stream is 10 Mbps. The results are as follows:
One-way delay: minimum 2 ms, average 12 ms, maximum 85 ms.
Delay Jitter: 4 to 33 ms.
Lost packets - 0.092%
Quite acceptable values, but if the stream was transmitted more intensively, the situation would have deteriorated significantly, since the throughput measurements showed that the channel speed was 12.7 Mbps
We had certain hopes for the third test, the signal level was quite good.
But the test results somehow did not please us ...
The bandwidth of the duplex channel was only 1.5 Mbit / s in each direction.
When transmitting an RTP stream with an intensity of 1451 kbit / s, the loss was 0.3%.
Jitter varied in the range from 12 to 300 ms
with a stream of 3 Mbit / s. the situation is even worse, losses from 1% to 2.3%, jitter from 32 to 110 ms
By ping, the situation is as follows:
1024 - Minimum = 4ms, Maximum = 12 ms, Average = 6 ms
16384 - Minimum = 46ms, Maximum = 205 ms , Average = 77 ms
65000 - Minimum = 181 ms, Maximum = 319 ms, Average = 243 ms (one lost)
Given the parameters of output power, receiver sensitivity and antenna gain from the datasheet to the access point, the expected signal level at the receiving point
was calculated : The calculation error was 4 dB, which is quite acceptable for such a distance.
Expected Coverage
According to the test results, the equipment has not yet met its expectations, unfortunately, we did not manage to play in detail with the settings at the farthest point, since they did not take charge from the second laptop and it died safely ... But the default settings clearly do not satisfy the manufacturer's stated speeds and our requirements for this equipment.
To be continued ...
Heading to the 2nd point (1.37 km.)
Heading to the 3rd point (5.54 km)
Location of the first point
Since this is not our first test and the circuit has already been tested for performance in the first test last summer, I will not describe the technique in detail.
Test number 1. The distance between the points is 10 meters.
The points are located in close proximity, the signal level is wonderful:
MIMO mode is felt in the equipment, the speed pleased
The speed failure was formed when a friend was between two antennas.
The average simplex channel speed was 42 Mbps (left).
In duplex mode, the points gave 26 Mbit / s in each direction and 52 Mbit / s in total (right).
Also, 10 pings were sent with a length of 1024, 16384 and 65000 bytes, the results are as follows:
1024 - Minimum = 1 ms, Maximum = 2 ms, Average = 1 ms
16384 - Minimum = 8 ms, Maximum = 11 ms, Average = 8 ms
65000 - Minimum = 19ms, Maximum = 28ms, Average = 22ms
Test number 2. The distance between the points - 1.34 km
At the maximum output signal level (28 dBm) at the receiving side, -61 dBm was obtained.
According to the test results, the situation is as follows:
In simplex mode, the average speed is 12.7 Mbit / s - in duplex 5.25 for transmission and 6.37 for reception .
A test was also conducted when transmitting IPTV real-time traffic (RTP). The intensity of the generated stream is 10 Mbps. The results are as follows:
One-way delay: minimum 2 ms, average 12 ms, maximum 85 ms.
Delay Jitter: 4 to 33 ms.
Lost packets - 0.092%
Quite acceptable values, but if the stream was transmitted more intensively, the situation would have deteriorated significantly, since the throughput measurements showed that the channel speed was 12.7 Mbps
Test number 3. The distance between the points - 5.54 km.
We had certain hopes for the third test, the signal level was quite good.
But the test results somehow did not please us ...
The bandwidth of the duplex channel was only 1.5 Mbit / s in each direction.
When transmitting an RTP stream with an intensity of 1451 kbit / s, the loss was 0.3%.
Jitter varied in the range from 12 to 300 ms
with a stream of 3 Mbit / s. the situation is even worse, losses from 1% to 2.3%, jitter from 32 to 110 ms
By ping, the situation is as follows:
1024 - Minimum = 4ms, Maximum = 12 ms, Average = 6 ms
16384 - Minimum = 46ms, Maximum = 205 ms , Average = 77 ms
65000 - Minimum = 181 ms, Maximum = 319 ms, Average = 243 ms (one lost)
Theoretical calculations
Given the parameters of output power, receiver sensitivity and antenna gain from the datasheet to the access point, the expected signal level at the receiving point
was calculated : The calculation error was 4 dB, which is quite acceptable for such a distance.
Expected Coverage
Summary
According to the test results, the equipment has not yet met its expectations, unfortunately, we did not manage to play in detail with the settings at the farthest point, since they did not take charge from the second laptop and it died safely ... But the default settings clearly do not satisfy the manufacturer's stated speeds and our requirements for this equipment.
To be continued ...
Small photo report
Heading to the 2nd point (1.37 km.)
Heading to the 3rd point (5.54 km)
Location of the first point