Difference between revisions of "Site selection"

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'''Planeación para escoger la ubicación para los equipos'''
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<!--T:1-->
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'''Planning site selection'''
  
  
== Qué equipos se instalan en esta ubicación ==
 
  
Las instalaciones para el servicio de telefonía requieren de una ubicación desde donde se pueda realizar la administración del sistema, de preferencia una oficina en alguna parte central del pueblo. También requiere otra ubicación donde se colocará la Radio Base Transceptor (BTS) que puede ser la misma para la administración del sistema. Sin embargo, hay que tener en cuenta algunos aspectos técnicos y de seguridad. Para obtener mayor detalle de los equipos que se requieren para una instalación puedes visitar la sección de este wiki [[Special:MyLanguage/Lista de componentes para la instalación del Sistema|Lista de componentes para la instalación del Sistema]].
+
== Equipment is installed at the location == <!--T:2-->
  
Para información más detallada sobre los equipos ensamblados en el mástil y los equipos en la oficina de administración dirigirse a la sección de este wiki [[Special:MyLanguage/Diagramas y Ensamblaje del Sistema|Diagramas y Ensamblaje del Sistema]].
+
<!--T:3-->
 +
The location of the telephony services requires a place from which the administration of the system can be done, preferably an office or some other centrally located place. It also requires finding somewhere to install the BTS, which can be in the same physical location as where the administration happens or can be somewhere else altogether. However, it is important to take into account some technical and safety considerations when deciding where to put equipment. To find out more about the equipment that is needed for each installation, visit the "LINK TO SECTION: Lista de componentes para la instalación del Sistema.".[[Special:MyLanguage/Lista de componentes para la instalación del Sistema|Lista de componentes para la instalación del Sistema]].
  
 +
<!--T:4-->
 +
For more more information about the installation visit [[Special:MyLanguage/Diagramas y Ensamblaje del Sistema|Diagramas y Ensamblaje del Sistema]].
  
== Un lugar seguro ==
 
  
El lugar donde se instalarán los equipos tiene que ser seguro para los equipos y para las personas que circulan alrededor de este sitio. En cuestión de seguridad para los equipos, nos referimos a un lugar en el cual los equipos estén resguardados de posibles robos, daños mal intencionados, condiciones ambientales y descargas eléctricas por variaciones de voltaje. Hay que tener en cuenta que estos equipos son bastante costosos y  han sido adquiridos de manera conjunta por la comunidad. Por ello, idealmente la comunidad deberá proporcionar una locación segura donde el acceso a los equipos sea limitado para evitar posibles daños.
 
  
Los equipos deberán estar protegidos de posibles daños causados por las condiciones ambientales, en específico lluvias, granizadas y descargas eléctricas. Para esto es recomendable realizar la instalación de pararrayos, y asegurarse que las instalaciones de electricidad se realicen adecuadamente, por ejemplo, proporcionando una toma de electricidad adecuada de 120 Voltios, y trifásica, lo que significa que los equipos tendrán tierra.
+
== A Safe Place  == <!--T:5-->
  
Para mayor información sobre pararrayos puedes leer los siguientes enlaces externos:
+
<!--T:6-->
 +
The place where equipment is installed must be safe both for the equipment and for the people near the equipment and site. As far as the safety of the equipment is concerned, we are mainly talking about finding a place where it will be safe from robbery or vandalism, as well as protected from environmental hazards, such as lightening or other problems like electrical surges. Don't forget, the equipment is not cheap and in many cases are the collective property of the community, so it's important the community provides a safe place that is reasonably accessible in order to ensure the safety and security of the equipment.
  
https://es.wikipedia.org/wiki/Pararrayos
+
<!--T:7-->
 +
It is important that the equipment be protected from environmental risks, particularly lightening, and so it is important that the installation site be properly grounded and protected.
  
Para evitar que los equipos se dañen por variaciones en el voltaje es recomendable instalar un No Break - regulador de voltaje. Cuando Rhizomatica realiza una instalación, deberá asegurarse que los equipos queden conectados al No Break - regulador de voltaje.
+
<!--T:8-->
 +
For more information on this, please visit this external link:
  
 +
<!--T:9-->
 +
https://en.wikipedia.org/wiki/Lightning_rod#Lightning_protection_system
 +
 +
<!--T:10-->
 +
In order to protect against current variations and spikes, we recommend installing a No Break or UPS, which is a voltage regulator with a battery included.
 +
 +
<!--T:11-->
 
[[File:No-break.jpg|center]]
 
[[File:No-break.jpg|center]]
  
En cuanto a la seguridad de las personas que circulen alrededor del sitio donde se instalarán los equipos con antenas, es importante advertir a la población que estos equipos emiten una radiación, ya que están emitiendo ondas y señales. Aunque estos equipos generalmente se colocan a una distancia fuera del alcance de las personas, siempre es importante advertirles que se trata de una zona con radiación, por lo que no se recomienda que estén expuestas por mucho tiempo.  
+
<!--T:12-->
 +
When it comes to the safety of people in the vicinity of the equipment, it is first necessary to make known to the general population that cellular equipment emits radiation. Although transmission equipment is usually installed at a reasonable distance from where people circulate, it is nevertheless a good idea to let people know about the effects of radiation close to the site and to maintain as much distance as they can from the transmission antennas.
  
Actualmente la IFETEL está realizando una consulta para determinar el "Anteproyecto de Disposición Técnica IFT-007-2015: Medidas de operación para el cumplimiento de los límites de exposición máxima para seres humanos a radiaciones". Para mayor información se puede ir al sitio de la IFETEL:
+
<!--T:13-->
 +
The IFETEL in Mexico is developing their ruling for radiation safety in Mexico, for for information you can go to their website:
  
 +
<!--T:14-->
 
http://www.ift.org.mx/industria/consultas-publicas/consulta-publica-del-anteproyecto-de-disposicion-tecnica-ift-007-2015-medidas-de-operacion-para-el
 
http://www.ift.org.mx/industria/consultas-publicas/consulta-publica-del-anteproyecto-de-disposicion-tecnica-ift-007-2015-medidas-de-operacion-para-el
  
http://www.ift.org.mx/sites/default/files/industria/temasrelevantes/4721/documentos/anteproyectodt-ift-007.pdf
+
<!--T:15-->
 +
For information on FCC Policy on Human Exposure to Radio frequency Electromagnetic Fields go to the following link:
 +
https://www.fcc.gov/general/radio-frequency-safety-0
  
  
== Cobertura ==
 
  
La tecnología GSM tiene un límite de 32km estándar, sin embargo, los equipos que utilizamos tienen una cobertura menor. La cobertura depende de varios factores: la ubicación topográfica de los equipos Radio Base y BTS, la recepción de los teléfonos celulares y en algunas ocasiones -aunque es cuestionable- las condiciones atmosféricas.
+
== Coverage == <!--T:16-->
  
Cuando hablamos de las condiciones topográficas, es importante recordar que las señales GSM son irradiadas dependiendo del patrón de la antena que se utilice. En Rhizomatica trabajamos con antenas omnidireccionales que distribuyen las señales de GSM a 360 grados a la redonda. Este tipo de antena se recomienda cuando está ubicada en el centro de la comunidad en un punto alto, así podrá cubrir a la comunidad a su alrededor.
+
<!--T:17-->
 +
GSM technology has a built-in overage limit of 32 kilometers, nevertheless, the equipment used and documented on this wiki has a smaller range of coverage. Coverage depends on various factors: topography and geographic location of the BTS and the user handset, as well as atmospheric conditions, foliage and other possible environmental factors that effect the propagation of radio signals.
  
 +
<!--T:18-->
 +
When speaking about topography, it is important to keep in mind that GSM signals propagate depending on the type of antenna used. We generally use omnidirectional antennas that spread the signal more or less evenly over a 360 degree horizontal plane. This type of antenna is recommended when installing in the center of a community or population.
 +
 +
<!--T:19-->
 
[[File:Antenna-omni.png|center|100px]]
 
[[File:Antenna-omni.png|center|100px]]
  
También utilizamos las antenas direccionales que distribuyen las señales GSM de forma direccional, lo que significa que concentra su potencia hacia la dirección en la que apunta. La parte posterior de la antena también emitirá la señal, pero esta será más débil. Este tipo de antena se recomienda, por ejemplo, cuando la antena está ubicada en alguna orilla alta del pueblo y se dirige hacia la comunidad.
+
<!--T:20-->
 +
We also use directional antennas that focus the energy of the BTS in a particular direction, depending on where they are pointed and the specs of the antenna. The back of the antenna will also emit and receive signal, but with little or no gain. This type of antenna is useful when installing in the edges of the community pointing at the town.
  
 +
<!--T:21-->
 
[[File:Antena-direccional.png|center|200px]]
 
[[File:Antena-direccional.png|center|200px]]
  
También es importante recordar que estas señales se transmiten bajo el principio de línea de vista, lo que quiere decir que aquellos aparatos receptores celulares puedan "ver" la antena dentro del perímetro de cobertura, y de contar con una recepción óptima, podrán recibir las señales. El sistema tiene una cobertura limitada debido a la potencia del transmisor dentro de la BTS. Este principio puede ser entendido utilizando la metáfora de una luz de faro, en la cual la luz del faro tiene una cobertura limitada de acuerdo a su posicionamiento topográfico y a la potencia del foco que emite la luz:
+
<!--T:22-->
 +
GSM signals are most easily thought of as being line-of-site, in other words, if there is a clear path between the antenna and the mobile handset, within the coverage area, there should not be any reception problems. GSM does penetrate most building materials, which allows for coverage indoors. It is unlikely that it will penetrate through dense foliage or through mountains or other geographic obstacles. If you imagine a lighthouse, the shadow or part where light can't reach because something is in the way will be places without coverage.
  
 +
<!--T:23-->
 
[[File:Faro luz.png|center|300px]]
 
[[File:Faro luz.png|center|300px]]
  
Si tenemos un objeto obstructor de por medio, la señal será absorbida por este cuerpo físico, lo que se traducirá en una conexión débil, inaudible, quebrada o nula. Así mismo, si se ha colocado la antena en un punto bajo de la comunidad, la señal será ahogada y por lo tanto, la cobertura será limitada:
+
<!--T:24-->
 +
This is why it is a good idea to install the BTS and antennas in a high place, in order to transmit and receive over physical objects that might obstruct the signal path and create poor reception and call quality.
  
 +
<!--T:25-->
 
[[File:Malaubicacionantena.png|center|350px]]
 
[[File:Malaubicacionantena.png|center|350px]]
  
La ubicación ideal de la Radio Base (BTS) deberá ser en la parte más alta de la comunidad. Si se utilizara una antena omnidireccional, la ubicación geográfica podrá ser en el centro de la comunidad. Si la ubicación será en un área periférica de la comunidad, lo ideal será utilizar una antena direccional que esté apuntando hacia la comunidad.
+
<!--T:26-->
 +
The ideal location of the Basic Radio (BTS) will have to be in the highest part of the community. If it used an omnidirectional antenna, the ideal geographic location for the antenna should be more or less in the centre of the community. If the location will be in a peripheral area of the community, the ideal will be to use a directional antenna aiming to the community.
  
Hay que recordar que, en ocasiones, las condiciones topográficas afectarán necesariamente la cobertura, lomas, barrancos, árboles, etc. El equipo de Rhizomatica realizará un recorrido por la comunidad para evaluar cuál es el lugar óptimo para colocar el equipo Radio Base (BTS), pero hay que tener en cuenta que esta locación deberá ser factible para la comunidad en cuestión de accesibilidad, seguridad y condiciones técnicas. Por ejemplo, si cuenta con una toma de corriente eléctrica y se comunicará a través de un enlace wifi con la Base Conotroladora (BSC), tiene que existir línea de vista directa entre estos dos puntos.
+
<!--T:27-->
 +
Due to possible negative effects on coverage from topographic and geographic realities, it is necessary to do a site survey before installing equipment and towers to find the optimum location in terms of coverage, safety and accessibility. For example if potential site needs a WiFi connection between the BSC and BTS, there must be line of site between the two locations.
  
Aunque en teoría las señales GSM no se deberían ver afectadas por las condiciones climáticas, se ha reportado en algunas comunidades la pérdida de señal o el debilitamiento de la misma debido a lluvias, granizo e incluso neblina. Esto se puede explicar debido a la humedad en el aire que crea condiciones más densas en la atmósfera y en consecuencia, resistencia entre las señales que se emiten GSM o wifi.
+
<!--T:28-->
 +
In theory, GSM signals should not be affected by climate or weather conditions, however in practice we have heard reports of this happening, specifically during heavy rains and fog, when coverage is seemingly affected. This is most likely caused by high levels of humidity that blocks or refracts the signal.
  
  
== Accesibilidad ==
 
  
Cuando se busca un sitio para colocar estos equipos debe pensarse en la accesibilidad del lugar. Por un lado, la comunidad debe tener en consideración que el lugar debe ser seguro para los equipos y así prevenir daños a los mismos. Por lo mismo, debe ser un sitio que tenga una accesibilidad limitada, pero que a la vez, sea un lugar accesible para checar posibles fallas técnicas y reparaciones. Idealmente, este lugar deberá contar con una instalación de electricidad, y las conexiones deberán estar protegidas de las condiciones climáticas que los puedan dañar, como lluvia, granizo, etc.
+
== Accessibility == <!--T:29-->
  
Si el lugar que se elige es en el techo de algún edificio, hay que procurar que el acceso a este sea restringido o mínimo, ya que como mencionamos con anterioridad, estos equipos emiten señales y radiaciones que no son recomendables para la exposición prolongada. El acceso restringido también protegerá los equipos de daños mal intencionados.
+
<!--T:30-->
 +
When looking for an installation site, accessibility is a key factor. The installation must be safe from easy theft and vandalism so neither too easily accessible or too isolated, but also accessible enough for technical repairs and maintenance to be done easily. The easiest thing is also for the site to have an electrical connection (of course properly grounded and protected from voltage spikes and lightening).
  
Si el equipo se ha colocado en una torre, la comunidad deberá asegurarse que esta torre se haya construido bajo las medidas necesarias de seguridad, es decir, que la torre esté fija y asegurada. El equipo de Rhizomatica no puede realizar reparaciones técnicas si no existen condiciones de seguridad para subir a la torre.
+
<!--T:31-->
 +
If the installation site chosen is on the roof of a building, ensure that access to the site or roof is restricted to protect people from radiation and the equipment itself from theft or damage.
  
 +
<!--T:32-->
 +
If instead a tower site has been chosen, it is imperative that the tower be properly installed and grounded to avoid accidents and damage to equipment.
  
== Condiciones técnicas ==
 
  
Las condiciones técnicas necesarias para poder realizar la instalación de la Radio Base (BTS) y antenas son dos:  
+
== Technical conditions  == <!--T:33-->
  
1) Que la ubicación cuente con una toma de corriente de 120 voltios trifásica. Esta toma de corriente deberá usarse exclusivamente para los equipos de la telefonía comunitaria.
+
<!--T:34-->
2) En caso de que se requiera la instalación de un enlace wifi para conectar la Base Controladora (BSC) con la Radio Base (BTS), estos dos lugares tienen que ser visibles entre sí para poder permitir la conexión, es decir, tiene que existir línea de vista. De no existir línea de vista los enlaces wifi no se podrán conectar.
+
There are some basic preconditions that, if unmet, will result in the equipment not working properly.
  
 +
<!--T:35-->
 +
1. There must be a standard 120v AC electrical connection with physical ground. This connection should be for the exclusive use of the equipment 2. In case a WiFi link is needed, there must be line of site between where the BTS will be installed and the location of the BSC, otherwise the WiFi links will not work properly.
 +
 +
<!--T:36-->
 
[[File:Enlace punto a punto.jpg|center|350px]]
 
[[File:Enlace punto a punto.jpg|center|350px]]
  
 +
<!--T:37-->
 
Dar click para regresar al Menú anterior [[Special:MyLanguage/Rhizomatica GSM|Rhizomatica GSM]]
 
Dar click para regresar al Menú anterior [[Special:MyLanguage/Rhizomatica GSM|Rhizomatica GSM]]
 +
 +
 +
== Click to go back to the previous Menu == <!--T:38-->
 +
 +
<!--T:39-->
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In some rural areas it is not uncommon to find fixed wireless terminals with high gain antennas or repeaters that are able to communicate and amplify very low and distant GSM signals that are not heard by normal mobile handsets. In many cases, the presence of these devices can create interoperability issues with community cellular installations. If there are many of these devices present or the community has invested in a signal repeater, these issues can potentially create conflict as this pre-existing service may be affected by the presence of the community cellular network.
 +
 +
<!--T:40-->
 +
This is how they work:
 +
 +
<!--T:41-->
 +
'''Fixed wireless terminals with high-gain directional (Yagi) antenna'''
 +
 +
<!--T:42-->
 +
These are essentially the same as mobile phones, except stationary and with the possibility of installing an external antenna. They use SIM cards and connect to the GSM network same as a normal mobile phone. In many cases, especially at the extreme limits of coverage of an existing GSM networks, these phone are connected to high-gain directional antennas. When a community network is installed close by, the receiver on these fixed wireless terminals can be "deafened" due to the very high gain antenna and the relatively high power of the newly installed signal, which means the phone no longer is able to receive the signal it once did from afar, even if the two networks are on different frequencies. The same thing can happen with repeaters. In Mexico, this problem is most common with Telcel fixed wireless terminals.
 +
 +
<!--T:43-->
 +
[[File:Telefono-fijo-rural-telcel-gsm-liberado-.jpg|300px]]
 +
 +
<!--T:44-->
 +
The phone has a directional Yagi antenna attached to it and installed on the roof or a mast:
 +
 +
<!--T:45-->
 +
[[File:Yagi-antena.png|File:Yagi-antena.png]]
 +
[[File:Antena-para-telefono-rural-telcel-unefon-huawei-.jpg|300px]]
 +
 +
<!--T:46-->
 +
The antenna amplifies the power of the signal going in to the receiver of the telephone, making it possible to community with very weak GSM signals. In many instances, the fixed terminal phone will then simply hop over the stronger signal (local community network) automatically. This can cause conflicts with those that already receive signal from afar as they lose their ability to connect to that signal when the community network is installed. In order to avoid these conflicts, Rhizomatica strongly prefers not to install in places where these types of phones are present. It is important that the community meet about this issue first, before communicating with us about installation plans.
 +
 +
<!--T:47-->
 +
Note: There are other types of fixes terminals that use wireless signals, but not GSM, to communicate, and these don't have any issue when a community GSM network is present. On the under side of the terminal or under the battery it generally says what frequency the phone uses and the directional antennas are usually much shorter that those for GSM.
 +
 +
<!--T:48-->
 +
'''Repeaters'''
 +
 +
<!--T:49-->
 +
Some communities without coverage install repeaters to capture and retrasmit at higher power, GSM signals from far away installations. When a community network is installed nearby, similar problems to those described above can happen. Specifically, the repeater begins repeating the community signal, instead of the one from far away. And for this reason, Rhizomatica strongly prefers to install networks far away from repeaters to avoid causing service interruptions to existing users of the repeater.
 +
 +
<!--T:50-->
 +
The only perceivable signal comes from a corporate site far away
 +
The repeater retransmits this signal as it is the only one it hears
 +
Strong new signal from the community network
 +
Weak signal from the other company
 +
The repeater repeats the closer, stronger signal, in this case the community's
 +
 +
<!--T:51-->
 +
[[File:Repetidora-otra-telefonia.png|File:Repetidora-otra-telefonia.png]]
 +
[[File:Repetidora-antena-rhizomatica.png|File:Repetidora-antena-rhizomatica.png]]
 +
 +
<!--T:52-->
 +
Repeaters are almost never installed by telecom companies, but rather by third-parties, and therefore generally do not conform to standards and regulations or have any kind of license to operate. The company whose signal is being repeated takes no responsibility for these repeaters.
 +
 +
<!--T:53-->
 +
Here is an example of how a repeater works as described on the site where it can be purchased.
 +
 +
<!--T:54-->
 +
''The Repeater captures the reliable cellular signal you have outdoors and rebroadcasts it indoors, up to 2,500 square feet, so you can enjoy clearer, faster and more reliable service without interruption. Remember, coverage varies based on outdoor signal level, building construction, and antenna placement. Coverage in adjoining rooms will be reduced by walls and ceiling/floors.''
 +
 +
<!--T:55-->
 +
[[File:Amplificador-de-senal-celular-rural-con-yagi-850-mhz-65-dbi-.jpg|File:Amplificador-de-senal-celular-rural-con-yagi-850-mhz-65-dbi-.jpg]]
 +
 +
<!--T:56-->
 +
Note: not all repeaters use Yagi or directional antennas.
 
</translate>
 
</translate>

Latest revision as of 03:41, 14 April 2016

Other languages:
English • ‎español

Planning site selection


Equipment is installed at the location

The location of the telephony services requires a place from which the administration of the system can be done, preferably an office or some other centrally located place. It also requires finding somewhere to install the BTS, which can be in the same physical location as where the administration happens or can be somewhere else altogether. However, it is important to take into account some technical and safety considerations when deciding where to put equipment. To find out more about the equipment that is needed for each installation, visit the "LINK TO SECTION: Lista de componentes para la instalación del Sistema.".Lista de componentes para la instalación del Sistema.

For more more information about the installation visit Diagramas y Ensamblaje del Sistema.


A Safe Place

The place where equipment is installed must be safe both for the equipment and for the people near the equipment and site. As far as the safety of the equipment is concerned, we are mainly talking about finding a place where it will be safe from robbery or vandalism, as well as protected from environmental hazards, such as lightening or other problems like electrical surges. Don't forget, the equipment is not cheap and in many cases are the collective property of the community, so it's important the community provides a safe place that is reasonably accessible in order to ensure the safety and security of the equipment.

It is important that the equipment be protected from environmental risks, particularly lightening, and so it is important that the installation site be properly grounded and protected.

For more information on this, please visit this external link:

https://en.wikipedia.org/wiki/Lightning_rod#Lightning_protection_system

In order to protect against current variations and spikes, we recommend installing a No Break or UPS, which is a voltage regulator with a battery included.

No-break.jpg

When it comes to the safety of people in the vicinity of the equipment, it is first necessary to make known to the general population that cellular equipment emits radiation. Although transmission equipment is usually installed at a reasonable distance from where people circulate, it is nevertheless a good idea to let people know about the effects of radiation close to the site and to maintain as much distance as they can from the transmission antennas.

The IFETEL in Mexico is developing their ruling for radiation safety in Mexico, for for information you can go to their website:

http://www.ift.org.mx/industria/consultas-publicas/consulta-publica-del-anteproyecto-de-disposicion-tecnica-ift-007-2015-medidas-de-operacion-para-el

For information on FCC Policy on Human Exposure to Radio frequency Electromagnetic Fields go to the following link: https://www.fcc.gov/general/radio-frequency-safety-0


Coverage

GSM technology has a built-in overage limit of 32 kilometers, nevertheless, the equipment used and documented on this wiki has a smaller range of coverage. Coverage depends on various factors: topography and geographic location of the BTS and the user handset, as well as atmospheric conditions, foliage and other possible environmental factors that effect the propagation of radio signals.

When speaking about topography, it is important to keep in mind that GSM signals propagate depending on the type of antenna used. We generally use omnidirectional antennas that spread the signal more or less evenly over a 360 degree horizontal plane. This type of antenna is recommended when installing in the center of a community or population.

Antenna-omni.png

We also use directional antennas that focus the energy of the BTS in a particular direction, depending on where they are pointed and the specs of the antenna. The back of the antenna will also emit and receive signal, but with little or no gain. This type of antenna is useful when installing in the edges of the community pointing at the town.

Antena-direccional.png

GSM signals are most easily thought of as being line-of-site, in other words, if there is a clear path between the antenna and the mobile handset, within the coverage area, there should not be any reception problems. GSM does penetrate most building materials, which allows for coverage indoors. It is unlikely that it will penetrate through dense foliage or through mountains or other geographic obstacles. If you imagine a lighthouse, the shadow or part where light can't reach because something is in the way will be places without coverage.

Faro luz.png

This is why it is a good idea to install the BTS and antennas in a high place, in order to transmit and receive over physical objects that might obstruct the signal path and create poor reception and call quality.

Malaubicacionantena.png

The ideal location of the Basic Radio (BTS) will have to be in the highest part of the community. If it used an omnidirectional antenna, the ideal geographic location for the antenna should be more or less in the centre of the community. If the location will be in a peripheral area of the community, the ideal will be to use a directional antenna aiming to the community.

Due to possible negative effects on coverage from topographic and geographic realities, it is necessary to do a site survey before installing equipment and towers to find the optimum location in terms of coverage, safety and accessibility. For example if potential site needs a WiFi connection between the BSC and BTS, there must be line of site between the two locations.

In theory, GSM signals should not be affected by climate or weather conditions, however in practice we have heard reports of this happening, specifically during heavy rains and fog, when coverage is seemingly affected. This is most likely caused by high levels of humidity that blocks or refracts the signal.


Accessibility

When looking for an installation site, accessibility is a key factor. The installation must be safe from easy theft and vandalism so neither too easily accessible or too isolated, but also accessible enough for technical repairs and maintenance to be done easily. The easiest thing is also for the site to have an electrical connection (of course properly grounded and protected from voltage spikes and lightening).

If the installation site chosen is on the roof of a building, ensure that access to the site or roof is restricted to protect people from radiation and the equipment itself from theft or damage.

If instead a tower site has been chosen, it is imperative that the tower be properly installed and grounded to avoid accidents and damage to equipment.


Technical conditions

There are some basic preconditions that, if unmet, will result in the equipment not working properly.

1. There must be a standard 120v AC electrical connection with physical ground. This connection should be for the exclusive use of the equipment 2. In case a WiFi link is needed, there must be line of site between where the BTS will be installed and the location of the BSC, otherwise the WiFi links will not work properly.

Enlace punto a punto.jpg

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In some rural areas it is not uncommon to find fixed wireless terminals with high gain antennas or repeaters that are able to communicate and amplify very low and distant GSM signals that are not heard by normal mobile handsets. In many cases, the presence of these devices can create interoperability issues with community cellular installations. If there are many of these devices present or the community has invested in a signal repeater, these issues can potentially create conflict as this pre-existing service may be affected by the presence of the community cellular network.

This is how they work:

Fixed wireless terminals with high-gain directional (Yagi) antenna

These are essentially the same as mobile phones, except stationary and with the possibility of installing an external antenna. They use SIM cards and connect to the GSM network same as a normal mobile phone. In many cases, especially at the extreme limits of coverage of an existing GSM networks, these phone are connected to high-gain directional antennas. When a community network is installed close by, the receiver on these fixed wireless terminals can be "deafened" due to the very high gain antenna and the relatively high power of the newly installed signal, which means the phone no longer is able to receive the signal it once did from afar, even if the two networks are on different frequencies. The same thing can happen with repeaters. In Mexico, this problem is most common with Telcel fixed wireless terminals.

Telefono-fijo-rural-telcel-gsm-liberado-.jpg

The phone has a directional Yagi antenna attached to it and installed on the roof or a mast:

File:Yagi-antena.png Antena-para-telefono-rural-telcel-unefon-huawei-.jpg

The antenna amplifies the power of the signal going in to the receiver of the telephone, making it possible to community with very weak GSM signals. In many instances, the fixed terminal phone will then simply hop over the stronger signal (local community network) automatically. This can cause conflicts with those that already receive signal from afar as they lose their ability to connect to that signal when the community network is installed. In order to avoid these conflicts, Rhizomatica strongly prefers not to install in places where these types of phones are present. It is important that the community meet about this issue first, before communicating with us about installation plans.

Note: There are other types of fixes terminals that use wireless signals, but not GSM, to communicate, and these don't have any issue when a community GSM network is present. On the under side of the terminal or under the battery it generally says what frequency the phone uses and the directional antennas are usually much shorter that those for GSM.

Repeaters

Some communities without coverage install repeaters to capture and retrasmit at higher power, GSM signals from far away installations. When a community network is installed nearby, similar problems to those described above can happen. Specifically, the repeater begins repeating the community signal, instead of the one from far away. And for this reason, Rhizomatica strongly prefers to install networks far away from repeaters to avoid causing service interruptions to existing users of the repeater.

The only perceivable signal comes from a corporate site far away The repeater retransmits this signal as it is the only one it hears Strong new signal from the community network Weak signal from the other company The repeater repeats the closer, stronger signal, in this case the community's

File:Repetidora-otra-telefonia.png File:Repetidora-antena-rhizomatica.png

Repeaters are almost never installed by telecom companies, but rather by third-parties, and therefore generally do not conform to standards and regulations or have any kind of license to operate. The company whose signal is being repeated takes no responsibility for these repeaters.

Here is an example of how a repeater works as described on the site where it can be purchased.

The Repeater captures the reliable cellular signal you have outdoors and rebroadcasts it indoors, up to 2,500 square feet, so you can enjoy clearer, faster and more reliable service without interruption. Remember, coverage varies based on outdoor signal level, building construction, and antenna placement. Coverage in adjoining rooms will be reduced by walls and ceiling/floors.

File:Amplificador-de-senal-celular-rural-con-yagi-850-mhz-65-dbi-.jpg

Note: not all repeaters use Yagi or directional antennas.