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Table of Contents

Performance tests

Web interface

The throughput test can be performed with the "Performance Tests" tool built into the web interface, in the section "Device status" → "Link statistics for the rf5.0 interface". This tool generate generates test traffic , between the devices and it allows to obtain data about the real link throughput both in one direction and in a two-way manner.  Throughput evaluation are made for The throughput evaluation is performed using traffic with the specified priority without taking into account the service traffic required to maintain the link operationoperational. To exclude the influence of the data traffic on the test's result, it is recommended to set the highest priority for the test traffic (at least 15). When the MINT testing mode is enabled (the "use MINT" checkbox), performance tests are always performed on the highest modulation, otherwise testing will be performed on each modulation available. The detailed description of the parameters description and the performance tests test settings is are available in the "Device Status menu" article.

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When using the command line interface to manage the device, it is possible to test the radio link via the "ltest" command.

Wireless

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link status

Link statistics on the rf5.0 interface

Web interface

To evaluate the quality of the wireless connection quality with the neighboring device, use the color indication in the "Status" column of the "Link statistics on rf5.0" subsection:

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The following symbols indicate problems:

  • At In the wireless connection uptime column:

    • F - the local device has a newer software version than the remote device.

    • E - the Ethernet port of the remote device is flapping.

  • At In the TX power column:
    • * - hardware device failure.
  • At In the RSSI column (only for software versions with TDMA technology support):
    • * - significant difference in the signals signal power of between the vertical and horizontal polarizations.

Make sure that the "TX Power" and "Bitrate" parameters match with the values of the planning phase. In the "Link statistics on rf5.0" of the "Device status" section, pay attention to the wireless connection parameters. The main parameters are the retries number and the bitrate. It is not recommended to use the link with the a retries number exceeding 5%. The actual bitrate (modulation level) depends on the SNR parameter - the signal-to-noise ratio. The highest modulations are available at SNR values of 27-50 dB.

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To display information about the wireless links link status via the command line interface, use the "mint rf5.0 map detail" command.

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Pay attention to the indicators in the "Options" column, the . The following values are possible:

  • M - Master device;
  • S - Slave device;
  • TM - Master device with software with having support for the TDMA technology support;
  • P - polling mode is enabled;
  • L - the throughput is limited by license;
  • F - the software version is older than the one on the local device.

A question mark in front of the remote's device name indicates that it has no password.

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  • At the "pwr" column - hardware device failure.
  • At the "rssi" column (only for software with TDMA technology support) - significant difference in between the signals signal power of the vertical and horizontal polarizations.

Radio statistics

Web interface

In case of a high retries level, use the built-in statistics tools. The "General statistics" section contains information about media loadingthe link load, queue overflow, etc..

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titleFigure - General statistics

Pay attention to the following indicators:

  • "Lost Frames"  the - the number of frames number that were not received by the device, even after retriesretrying.
  • "Duplicates Received" - the number of frames number that were received several times due to because the other side did not receive an acknowledgment of the frame receipt.
  • "Aggr Subframe Retries" and "Aggr Full Retries" the frames number that  - the number of frames that the device has sent several times because the other side did not acknowledge the receipt.
  • "Exscessive Excessive Retries" the frames number failed to send  - the number of frames that failed to to be sent after all the retry attempts.

Command line interface

To display statistic statistics via the command line interface, use the ""rfconfig stat" command.

QoS

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statistics

Web interface

The "QoS statistics" section provides information about the transmitted and dropped packets in each priority queue configured on the device. Drops present in the traffic processing queues indicates indicate that the throughput threshold has been exceeded. Losses in queue q00 (P16) are acceptable because this queue contains performance test data.

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To display statistic via the command line interface, use the "rfconfig rf5.0 stat qoscommand. The number of dropped packets number for each configured queue can be displayed by the "qm stat" command.

Statistics graphs

If the link has deteriorated during its operation, with having the initial parameters corresponding to the calculated ones, it is necessary to find out when the problem has beginoccured. Use the "Statistics graphs" tool to determine when or how often the problem occurs by changing the display options.

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titleFigure - Statistics graphs

Device status

Pay attention to the CPU and memory usage indicators in the "Device status" section. Excessive processes running on a device can overflow the volatile memory and overload the CPU (over 95% usage), and deteriorate leading to a deterioration in the wireless link's quality. The CPU load can be displayed with using the "system cpu" command, and  and information about the device's memory state by can be shown using the "mem" command.

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titleFigure - CPU and memory usage

Last reboot reason

Disruptions in the wireless link may be caused by the reboot of the device reboot.  At In the "Maintenance" section or at in the "system uptime" command output pay attention to the last device reboot reason.  Following The following values are possible:

  • "Software fault".
  • "Unexpected restart".
  • "Manual restart".
  • "Manual delayed restart".
  • "Firmware upgrade".
  • "SNMP managed restart".
  • "Test firmware loaded".
  • "Power-on reset".

System log

Proceed to the System Log tool in the "Device status" section or by using the "system log" command. Using the log entries, check if the link degradation was caused by a configuration change ("system reconfiguration" message). Restore the configuration previous version of the configuration if necessary. Detailed information about saving and uploading the configuration is available in the "General Purpose Command Set" article.

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Messages in the logDescription
Link DOWNThe wireless link has been disconnected. The reason for the disconnection is indicated in the same entry.

"too many transmit errors"

The wireless link was interrupted due to transmission errors.

"link reconnecting"

The wireless link is reconnectedreestablished.
"no signal from the remote side detected"There is no signal received, check the remote device.
Scrambling engine overflowThe hardware capabilities of the scrambling module are exceeded. To connect more subscribers (more than 62) scrambling should be disabled.
Warning: Abnormal transmit power disbalance!May indicate a hardware problem.

Частое изменение статуса Ethernet-интерфейса Frequent changes in the status of the Ethernet interface ("Up" и and "Down") может свидетельствовать о проблемах интерфейса Ethernet, подключенного к нему кабеля, источника питания или коммутатора.

Юстировка антенны

Web-интерфейс

Деградация канала связи может быть вызвана нарушением юстировки или появлением препятствий на пути распространения сигнала. Воспользуйтесь встроенным инструментом "Юстировка антенны". Рекомендуемые параметры указаны в таблице ниже. Если параметры связи существенно отличаются от расчётных, проверьте точность юстировки устройств с обеих сторон канала связиmay indicate problems with the Ethernet interface, the cable connected to it, with the power supply, or with the switch.

Antenna alignment

Web interface

The link degradation can be caused by antenna misalignment or by the appearance of obstacles along the signal's propagation path. Use the built-in "Antenna Alignment Tool". The recommended parameters are shown in the table below. If the parameters differ significantly from the calculated ones, check the alignment accuracy on both link sides.

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Абсолютное значение EVM (дБАбсолютное значение

RSSI (дБмdBm)

-90 ... -80

Значение близко к уровню чувствительности приемника, доступны только низшие модуляцииThe value is close to the receiver sensitivity level, only lower modulations are available

-80 ... -60

Средний уровень мощности принимаемого сигналаLow level. Average modulations are available

-60 ... -40

Оптимальный уровень мощности сигнала на приёме для достижения максимальной производительностиThe recommended value for maximum performance

>-40

Слишком высокий уровень мощности принимаемого сигнала

The received signal level is too high

Absolute value EVM (dB)

>21Оптимальное

значениеRecommended value

CINR (дБdB)

>28

Доступны высшие модуляции

Higher modulations are available

Absolute value Crosstalk (дБdB)

>20

Оптимальное значение

Сохранение параметра RSSI на высоком уровне при снижении значений параметра CINR может свидетельствовать о помехе вблизи одного из устройств. Ухудшение параметров RSSI и CINR, может быть показателем нарушения юстировки устройств. Подробное описание работы инструмента "Юстировка антенны" доступно в соответствующем разделе статьи "Состояние устройства". 

Интерфейс командной строки

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Recommended value

If the value of the RSSI parameter remains high while the CINR value decreases, it may indicate high interference levels near one of the devices. The deterioration of both the RSSI and the CINR parameters can indicate a  misalignment of the devices. A detailed description of the "Antenna Alignment" tool is available in the "Device status menu" article

Command line interface

When using the command line to manage the device, fine antenna alignment can be performed using the "ltest rf5.0 MAC ADDRESS -align" . В выводе команды будет указано среднее значение CINR для локального и удалённого устройстваcommand. The command output will show the average CINR for the local and the remote devices.

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titleРисунок Figure - Вывод команды "ltest - align" command output

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Analysis of the radio environment

Web -интерфейсДля оценки состояния радиосреды обратитесь к инструменту interface

To assess the state of the radio environment proceed to the "Radio Scanner" . Инструмент имеет следующие назначения:

  • позволяет оценить источники радиоизлучения на текущей центральной частоте и, при необходимости, выполнить частотное разнесение устройств с целью снижения их взаимного влияния;
  • выводит информацию о импульсных помехах. Количество импульсов в секунду свыше 50 говорит о существенных помехах на выбранной частоте. 

Для выбора частоты свободной от помех используйте инструмент "Спектроанализатор", либо воспользуйтесь механизмами автоматического выбора частоты. Подробнее об алгоритмах динамического выбора рабочей частоты можно узнать в статье "Динамический выбор частоты"tool. The tool has the following purposes:

  • allows to evaluate the radio sources on the current central frequency and, if necessary, perform frequency diversity in order to reduce their mutual influence;
  • displays information about the impulse noise. A number of pulses per second over 50 indicates significant interference on the selected frequency. 

Use the "Spectrum Analyzer" tool to select a frequency free from interference or use the automatic frequency selection mechanisms. For more information about the dynamic frequency selection algorithms proceed to the "Dynamic Frequency Selection" article.

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titleРисунок Figure - Radio Scanner

Интерфейс командной строки

Более подробная информация о состоянии радиосреды доступна посредством команды Command line interface

Detailed information about the state of the radio environment is available via the "muffer" command. Так команда The "muffer rf5.0 scan" позволяет выполнить глубокий анализ радиосреды на наличие источников радиосигналов на всех доступных частотахcommand allows to check the radio environment for the presence of radio signal sources on all the available frequencies.

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titleВНИМАНИЕNOTE

Выполнение команды The "muffer rf5.0 scan"  может занять значительное время и нарушить нормальную работу радиомодуляcommand can take a long time to execute and disrupt the normal operation of the radio module.