> For the complete documentation index, see [llms.txt](https://wiki.astrawireless.net/astra-wireless-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.astrawireless.net/astra-wireless-documentation/technical-documentation/astrawireless-evolution-technical-user-manual/planning-considerations.md).

# Planning considerations⁣⁣⁣⁣⁣⁣⁣⁣⁣

During link planning, such factors as distance, obstacles and the link margin should be taken into account. We strongly recommend to use a [planner tool](https://planner.astrawireless.net/) for link planning.

### Range and obstacles <a href="#planningconsiderations-rangeandobstacles" id="planningconsiderations-rangeandobstacles"></a>

Make sure that line of sight is provided when planning the antennas' placement for a point-to-point link in order to achieve maximum range and performance between two antennas. Perform a survey to identify all the obstructions (such as trees or buildings) in the path and to assess the risk of interference.

The radio beam is an electromagnetic wave and it is not as thin as a laser beam, for example. The main energy in a radio beam is concentrated along the straight line between the two antennas, inside an area with the shape of an ellipsoid (or a rugby ball). This area is called the 1st Fresnel zone and its exact form and size depend upon the frequency and the signal propagation path length.

If most of the 1st Fresnel zone is obstructed, a major part of the radio wave’s electromagnetic energy is lost, which leads to a severe signal quality degradation and as a result to a decreased coverage range or performance.

Below is an incomplete list of possible obstructions along the signal propagation path:

* Neighboring buildings.
* Trees.
* Bridges.
* Power lines.

To obtain the best results, it is necessary to perform a precise analysis of the signal propagation path and possible obstructions that may obstruct the 1st Fresnel zone.

<figure><img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FDrY2mBikKxaQDpCNPV9s%2Fimage.png?alt=media&amp;token=5d8fff67-f9c8-4464-9a2d-7bca1e951ba3" alt=""><figcaption></figcaption></figure>

### Antenna Installation <a href="#planningconsiderations-antennainstallation" id="planningconsiderations-antennainstallation"></a>

General recommendations for antenna installation:

* Try to keep the LOS clear of obstructions. In case of installations over vegetation and forest, make sure the direct LOS stays above the trees; in urban environments - above the tallest buildings along the radio path.
* The influence of trees can be variable, depending on the season (ice, dew, leaves). Keep in mind that, during spring and summer, leaves can absorb high levels of radio energy. Therefore, when installing during the cold season, over forests and trees without leaves, try to achieve a higher fade margin.
* Install the devices at a distance of at least 100-150 meters from power lines having a voltage higher than 35 kV.
* Before installation, make sure the devices are located outside the area of water streams and splashes formation, which can affect the enclosure for a long time.
* Install antennas as far as possible from other antennas (the recommended distance is at least 2 meters between edges of the antennas).
* Reflecting surfaces should be considered (buildings with reflective windows, water surfaces or wet grounds). These can be useful in NLOS situations, if there is no direct clear path between the 2 antennas, so the radio signal needs to be reflected by a surface. However, reflections can also decrease the signal quality when encountered along a clear LOS link, because of fading caused by multipath propagation.
* When installing antennas over the water, tune the height bracket within a 1-3 meters range variation, because it can yield significant signal level variations due to multipath fading.

<figure><img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FdyVPpubsm1MhOgJkqIKF%2Fimage.png?alt=media&amp;token=26bd182f-06aa-4ffb-b29b-2e8c2d42422d" alt=""><figcaption></figcaption></figure>

### Spectral aggregation <a href="#planningconsiderations-spectralaggregation" id="planningconsiderations-spectralaggregation"></a>

It is recommended to place base station sectors above the subscriber terminals as high as possible to provide proper antenna tilt in vertical direction and to minimize self-interference. The optimal antenna tilt is defined by the vertical beam width of the sectoral antenna and by the required sector coverage. It must cover all the area, where you plan to deploy the subscriber terminals.

Spectral aggregation should be taken into account when planning composite backhauling links, when installing devices in close proximity to each other on the same pole or in order to implement redundancy and link aggregation. For more information, proceed with the "[Link aggregation, balancing and redundancy](/astra-wireless-documentation/white-papers/link-aggregation-balancing-and-redundancy.md)" article. The devices located close to each other can cause mutual interference. Do not ignore the spectral aggregation rules, otherwise it can lead to a degradation of the wireless links.

The document will provide recommendations on distance and frequency separation for scenarios with and without an external synchronization hub. An external clock source allows you to synchronize the time (the beginning of each second) on multiple devices, up to 7 devices, with an accuracy of less than a microsecond so that all connected devices can turn on the transmitters at the same time. This completely eliminates the mutual influence of neighboring sectors, when one transmitting device with its powerful signal prevents the neighboring device from receiving weak signals from its terminals. Wireless devices synchronization using AUX-ODU-SYNC makes it possible to reuse the frequency within the same base station, that is, different sectors of the same base station can operate on the same frequency channels. When using synchronization, a four-sector base station can operate on only two frequency channels, significantly increasing the real spectral efficiency of the system.

Mutual interference occurs not only between sectors and subscriber terminals of one multi-sector base station, but also between different base stations when they are densely located in a limited frequency range. Synchronization of base stations prevents mutual interference of such base stations and subscriber terminals that working with them.

Recommendations for istance and frequency separation for a four-sector ABAB base station are given below.

#### Without synchronization <a href="#planningconsiderations-withoutsynchronization" id="planningconsiderations-withoutsynchronization"></a>

* Distance separation (vertical or horizontal) must be at least two meters between the edges of the antennas.
* Reduce the transmission power.

#### With synchronization <a href="#planningconsiderations-withsynchronization" id="planningconsiderations-withsynchronization"></a>

4 collocated base stations mounted back-to-back. The recommended guard interval between the end/boundary frequencies of the occupied bands of the neighboring sectors 5 MHz.

<figure><img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FBoc2uqkTdNH9j8ysfTXT%2Fimage.png?alt=media&amp;token=ad4e7f06-42fc-4c4f-b03b-678c65eef7c4" alt=""><figcaption></figcaption></figure>

### Synchronization settings <a href="#planningconsiderations-synchronizationsettings" id="planningconsiderations-synchronizationsettings"></a>

To perform synchronization using an external hub, each base station sector must be connected to an AUX-ODU-SYNC.

The following conditions should be met:

* Frame size and DL/UL ratio should be equal on all sync-end units.
* The automatic downlink ratio selection is not allowed.

{% hint style="warning" %}
NOTE

The AUX-ODU-SYNC antenna is not included in the standard packing list.
{% endhint %}

#### Configuration via web interface <a href="#planningconsiderations-configurationviawebinterface" id="planningconsiderations-configurationviawebinterface"></a>

To enable synchronization via web interface:

* Go to the section "Basic Sttings" → "Link Settings" → "rf6.0".
* Check the box "Use AUX-ODU-SYNC" and click "Apply". Synchronization status and the number of visible satellites is displayed in the "Device Status" -> "Link Statistics" section.

<figure><img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FY3PR35Abugbtrc3eIKjT%2Fimage.png?alt=media&amp;token=dee2024f-eef3-45d3-89ce-02339f9cc169" alt=""><figcaption></figcaption></figure>

Additionally in order to determine the device coordinates GNSS position can be enabled.

* Go to the section "Basic Settings" -> "System Settings".
* Check the box "Enable GNSS Receiver" and click "Apply" button.

<figure><img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FcG9DWLu1MMgqpIWYVBPf%2Fimage.png?alt=media&amp;token=a20ee606-7e78-4353-aa93-4ce6dd38b36e" alt=""><figcaption></figcaption></figure>

Click "Open map" to view the device location. The map is updated in real time that allows to monitor the movement of the device mounted on the mobile object.

#### Configuration via CLI <a href="#planningconsiderations-configurationviacli" id="planningconsiderations-configurationviacli"></a>

Enable synchronization:

```
// tsync enable
```

The synchronization mode information:

```
// tsync
```

The following parameters will be displayed:

<table><thead><tr><th width="246">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><strong>Total GPS time</strong></td><td>Total time of GPS operation</td></tr><tr><td><strong>Total nonvalid time</strong></td><td>Total time during which the information about coordinates was unavailable</td></tr><tr><td><strong>Number of losses</strong></td><td>Quantity of cases when the information about coordinates had become unavailable</td></tr><tr><td><strong>Now coordinates are valid last ...</strong></td><td>Time of GPS operation since last coordinates discovering</td></tr><tr><td><strong>Sattelites histogram</strong></td><td>Histogram of visible satellites quantity</td></tr><tr><td><strong>SATmin</strong></td><td>Minimum of visible satellites (since the last time you cleared the statistic)</td></tr><tr><td><strong>SATmax</strong></td><td>Maximum of visible satellites (since the last time you cleared the statistic)</td></tr></tbody></table>

## Important notice

{% hint style="warning" %}
NOTE

<img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FPprKo03q2w3lWQx0qakP%2Fimage.png?alt=media&amp;token=e65e8bc3-c5e9-4704-928e-25f298a38bda" alt="" data-size="line">Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

* Reorient or relocate the receiving antenna.
* Increase the separation between the equipment and receiver.
* Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
* Consult the dealer or an experienced radio/TV technician for help.
  {% endhint %}

{% hint style="warning" %}

NOTE

<img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FUrZuTNtcMdm0ROdgVpGp%2Fimage.png?alt=media&amp;token=324682f2-114b-40cc-9884-e3f0e9b02033" alt="" data-size="line"> <img src="https://2734851754-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnG7V17JtC1mMJOmveKc6%2Fuploads%2FOGHffNfvxGryAdW26Agb%2Fimage.png?alt=media&amp;token=586d0711-ff5a-40b6-b879-c0deff24a29a" alt="" data-size="line">On the territory of the European Union, following applies:

* the band 5150–5350 MHz is only for indoor use to reduce the potential for harmful interference to co-channel mobile satellite systems and other services. Further, EU regulations enforce EIRP limit in that band of 200mW (23dBm), output power and antenna gain (in case of devices with detachable antenna) shall be chosen accordingly;
* in the band 5470-5725 MHz, choice of the transmit power and antenna gain (in case of devices with detachable antenna) shall be such that the equipment still complies with the EIRP limit and EIRP density limit. EIRP limit in that band is 1W (30dBm), EIRP density limit is 50mW/MHz (17dBm/MHz);
* in the band 5725-5875 MHz, choice of the transmit power and antenna gain (in case of devices with detachable antenna) shall be such that the equipment still complies with the EIRP density limit. EIRP density limit in that band is 200mW/MHz (23dBm/MHz).
  {% endhint %}

{% hint style="warning" %}

NOTE

This device contains licence-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and Economic Development Canada’s licence-exempt RSS(s). Operation is subject to the following two conditions:

* This device may not cause interference.
* This device must accept any interference, including interference that may cause undesired operation of the device.

This Class B digital apparatus complies with Canadian ICES-003.

Following also applies to this radio equipment:

* the band 5150–5250 MHz is only for indoor use to reduce the potential for harmful interference to co-channel mobile satellite systems;
* for devices with detachable antenna, the maximum antenna gain permitted for devices in the bands 5250-5350 MHz and 5470-5725 MHz shall be such that the equipment still complies with the e.i.r.p. limit;
* for devices with detachable antenna, the maximum antenna gain permitted for devices in the band 5725-5850 MHz shall be such that the equipment still complies with the e.i.r.p. limits as appropriate; and
* where applicable, antenna type(s), antenna models(s), and worst-case tilt angle(s) necessary to remain compliant with the e.i.r.p. elevation mask requirement set forth in section 6.2.2.3 of the RSS-247 shall be clearly indicated.\
  High-power radars are allocated as primary users (i.e. priority users) of the bands 5250-5350 MHz and 5650-5850 MHz and these radars could cause interference and/or damage LE-LAN devices.
  {% endhint %}

{% hint style="warning" %}

REMARQUE

Cet appareil contient des émetteurs / récepteurs exemptés de licence conformes à la (aux) source(s) RSS de Innovation, Sciences et Développement économique Canada. Le fonctionnement est soumis aux deux conditions suivantes:

* Cet appareil ne doit pas causer d'interférences.
* Cet appareil doit accepter toutes les interférences, y compris celles susceptibles de provoquer un fonctionnement indésirable de l'appareil.

Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.

Ce qui suit s’applique également à cet équipement radio:

* la bande 5150–5250 MHz est uniquement destinée à une utilisation en intérieur afin de réduire le risque de brouillage préjudiciable des systèmes de télécommunication par satellite mobiles dans le même canal;
* pour les dispositifs avec une antenna détachable, le gain d'antenne maximal autorisé pour les dispositifs des bandes 5250-5350 MHz et 5470-5725 MHz doit être tel que l'équipement soit toujours conforme à la norme e.i.r.p. limite;
* pour les dispositifs avec une antenna détachable, le gain d'antenne maximal autorisé pour les dispositifs de la bande 5725-5850 MHz doit être tel que l'équipement soit toujours conforme à la norme e.i.r.p. limites, le cas échéant; et
* le cas échéant, type (s) d’antenne, modèle (s) d’antenne et angle (s) d’inclinaison dans le cas le plus défavorable nécessaire pour rester conforme à la norme e.i.r.p. L’exigence de masque d’altitude énoncée à la section 6.2.2.3 du CNR-247 doit être clairement indiquée.\
  Les radars à haute puissance sont attribués en tant qu'utilisateurs principaux (utilisateurs prioritaires) des bandes 5250-5350 MHz et 5650-5850 MHz, et ces radars peuvent provoquer des interférences et / ou endommager les dispositifs LE-LAN.
  {% endhint %}

{% hint style="warning" %}
Este equipamento não tem direito à proteção contra interferência prejudicial e não pode causar interferência em sistemas devidamente autorizados. Para maiores informações, consulte o site da ANATEL
{% endhint %}