Deployment of a 7km Point-to-Point Wireless Link

Ifrane, Morocco 2006

Problem Statement: Two administrative buildings (Atlas and Agdel) in the city of Fez needs to get inter-connected. The connection should allow the establishment of an Intranet to share e-government services.

Conditions: The two buildings are separated 1.5 kms but there is not Line of Sight (LOS) due to high buildings.

Action: During the North African Training Workshop in Wireless Community Networks, [Ifrane, Morocco] we planned and deployed a radio link that will allow the connection of the two builds. In order to get the two buildings connected it was needed to study the possibility of relying the radio signal in a mountain 7 kms away. As a result of using a high remote relay we wanted to explore the possibility of adding more sites to the wireless hub in the future.

Training

During three days of intensive training, we covered all aspects of a wireless network deployment including radio physics and link budget, antennas and cables, antenna construction and outdoor radio simulation. Theoretical sessions were followed by small lab practices and exercises. The following link include a list of the wireless training materials.

Preparation and Planning

Planning the link with Radio Mobile.


An initial simulation of the radio link was conducted with Radio Mobile. The first picture shows the difference of elevation of 500 meters between the mountain and the two sites.



This second satellite picture shows the mountain and the city of Fez (50 degrees SE). All the potential sites to be covered are in the range (distance: 5-10 kms) angle: (0-90 degrees). For this concrete case of the two sites (Atlas and Agdel) an antenna with 20 degrees aperture in the mountain is suitable to cover the two sites in one single sector.

Equipment

Mountain/Hub :

  • Configuration A: Linksys Wireless Router WRT54G + RP-TNC-SMA (1m) pigtail + Smarteq 14 dBi Cavity Antenna (Vertical Polarization, 22 degrees H)
  • Configuration B: Linksys Wireless Router WRT54G + RP-TNC N-Male (1 m) pigtail + Smarteq 12 dB Panel Antenna (Vertical Polarization, 70 degrees H)

The following picture shows a part of the Wireless Training Kits used during the Lab practices

Site Atlas/Client :

The following configurations were tested in the client site

  • Configuration A: Laptop, Orinoco PCMCIA Card (15 dBm), pigtail, 9 dBi Panel Antenna
  • Configuration B: Laptop, Senao PCMCIA Card (23 dBm), pigtail, 9 dBi Panel Antenna
  • Configuration C: Laptop, Orinoco PCMCIA Card (15 dBm), pigtail, 10-12 dBi Cantenna
  • Configuration D: Laptop, Senao PCMCIA Card (23 dBm), pigtail, 10-12 dBi Cantenna
  • Configuration E: Laptop, Senao/Orinoco PCMCIA Card (23 dBm), pigtail, 3 meters low loss cable, 9 dBi Cantenna

Selecting and Testing Equipment


At the end of the second day after the antennas and cables theoretical session we built 30 can-tennas. Notice the amount of human resources required for the construction of a low budget antenna. More than 10 kilos of pineapple were also eaten during the event.


Each antennas was tested and certified. The best antennas were chosen for the long distance link. A few antennas scored 10-12 dBi gain.

Implementation

The following picture shows the hub site at the top of the mountain. Notice the last-minute heat protection of the access point. Temperature at the top of the mountain was well over 45 C.

Mountain/Hub: Specs Cavity Antenna, 14 dBi

Site Atlas/Client: Home-Workshop made 'Cantenna', ~12dBi

Testing the radio link from the client site

Results

A presentation prepared by the team with the results of the radio link is available to download here [Arabic, 2.1 M]

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