Module Two - Preface

Wireless Network Installation.

The focus of this module is the creation of a wireless network. The main goal is to teach wireless network hardware installation which will enable two or more devices to communicate with one another, without the need for a physical wire directly connecting them. As with the first module, software and network configuration details are not covered in this module. User manuals for software and equipment purchased will be required for final setup of the installed wireless technology.

Safety Reminder

Please review the safety overview for these modules and for this specific module before proceeding with any work. Please be safe. Throughout these modules, we have stressed SAFETY in all aspects of network installation - safety is of the UTMOST importance!

Wireless Background

So what is wireless? Wireless technology, at its very basic level, is any technology that can transmit a signal (data, voice, or otherwise) from one location to another, without a physical connection between the two locations. The first wireless technology was developed in 1896, by Guglielmo Marconi. His technology eventually became what we know today as radio. The process of sending information over the "airwaves" since that time has been used for many different applications, including telegraph, telephone, radio, and data communications. Wireless data communication uses similar technology and medium as a radio, but it needs specific technology on both ends of the signal to send and receive the data properly, in a way that we can use it.

After Marconi, a wireless technology was developed during the 1940's and Patented in 1942 by Hedwig Kiesler and her neighbor at the time, George Antheil. This technology used a broad spectrum of radio waves to send small portions of data, a bit at a time, on many different radio frequencies. Hedwig was known as "Hedy Lamarr" (left) and as a famous Hollywood actress for MGM in the 1940's, was at one time called the "most beautiful woman in Hollywood." Antheil was famous in his own right, as a concert pianist and composer, and part of the timing mechanism for their invention was based upon player piano technology.

Frequency Hopping: The main concept behind the wireless technology invented by Lamarr (Kiesler) and Antheil is known as "frequency hopping." As this was during World War II, both inventors were interested in developing ways of controlling torpedoes remotely, in such a way that the signals could not be intercepted. The basic idea developed is that the signals sent are spread over a large spectrum of radio frequencies, which is where the term "spread spectrum" comes from. The data itself then is divided up into small bits and spread over the frequency, while both the sending device and the receiving device switch between frequencies at the same time. This is called frequency hopping, and is done by accurately timing the sending and receiving devices so that they hop from the same frequency to another same frequency at the exact same moment, in order to exchange information. Click here for more information on frequency hopping.

Frequencies: Demand for wireless technology has grown, largely due to increased Internet usage. Because of this, increased amounts of data are being placed on wireless frequencies, which has necessitated the creation of regulations to enable fair sharing of wireless frequencies between all users and wireless technology types. For more information on division of frequencies, click here.

Wireless Advantages: There are several advantages to installing wireless networks in rural and remote locations that make this technology ideally suited for description in this context. In short:

• Mountains and rough terrain can be a GOOD THING for wireless installations

• Wireless can be cheaper to install
  
• Wireless is a flexible technology

While mountainous and difficult terrain is a problem for installing cable-based technologies, mountains can be advantageous for wireless installations.

Mountains are an asset for wireless as they offer an ideal place to install wireless towers. In flatter or less "geographically challenging" areas such as the prairies, much taller towers are required (sometimes more than two hundred feet tall) which can make this technology cost-prohibitive for those areas.

In addition to wireless technology being potentially cheaper as it is far easier to install in very remote areas, it offers the additional benefit that it is not a tariffed service in the same way that copper-wire voice-based data circuits are. These services, because they are generally so costly to put in place by running wire to remote locations, are tariffed across the board by the CRTC (Canadian Radio-television and Telecommunications Commission). The tariffs charged are then used to subsidize the cost of running the cable to remote areas. Wireless technology offers a degree of flexibility not offered by other technologies. If a wireless antenna is mounted on a temporary or semi-permanent tower, or on the side of a building, it can generally be easily moved (certainly more easily than wires on poles or wires in conduit) to compensate for environmental changes that can effect the signal, such as tree growth that blocks line of sight.

This technology can offer interesting partnership opportunities for communities sharing bandwidth, construction, and/or maintenance of wireless "hops" - links to towers which can be shared on nearby hills between communities.

An example of how wireless works: It may help to understand how wireless could apply to your organization or community by looking at a specific example to understand how it might work. In the diagram below, following the blue line from left to right will show two communities hook their networks together and to the Internet, using wireless technology.

• Community "A" has their own ethernet, which they hook into a central location in one of the buildings in their community.
  
  
• On the roof of the building where their network lives, Community "A" installed a simple tower with a wireless antenna, and linked it to their network.
  
  
• The wireless antenna is pointed at another antenna on a hill nearby their town.
  
  
• The antenna then sends the signal along to another TV tower, further away and near a different community.
  
  
• In the second community, there is a wireless connection from their tower to the building where their network is, and they have an ethernet which connects via another wireless hop to their network building.
  
  
• A fibre line in the building where their network is connects their wireless unit to a CSU / DSU, which is a specialized piece of technology to connect to a T1 fast line.
  
  
• The T1 line is a direct line out to the Internet.

Though it may sound complicated, this is actually quite a simple and potentially more cost-effective way of networking communities, particularily in remote areas where the geography is too challenging to install wire-based networking technology such as coaxial able or fibre-optic.

Different Topologies: In Module One, different types of LAN networks were looked at: point-to-point, and point-to-multipoint. Similar topologies exist in wireless networking technology, with different topologies generally having different uses. The different types are illustrated below.

• Point-to-point: This wireless technology is a link between two points. It is like having a patch-cord between two computers, only without the patch cord! This type of link is generally used for long distance links between hilltops or towns, or along valleys.
  
  
• Point-to-multipoint: This is a shorter range type of wireless connectivity, and is generally used for distances to a maximum of five to seven kilometres. As the name indicates, this topology connects one point (such as a wireless hub) to many points (such as laptops or workstations with wireless access.)

Flawless Connectivity for remote communities? Unfortunately, wireless technology, despite its many advantages, is not a flawless method for connecting rural and remote communities. Because it is an "indirect" type of connection, it can be affected by environmental issues. Generally speaking, wireless connections prefer to have a clear line of sight between antennas and/or access points, which means that anything that could create a barrier to a clear line of sight could cause problems with the connection. Common environmental conditions and objects which have been known to cause wireless network difficulties include: mountains, large rocks, trees, poor weather, smoke, stratus cloud formation over water (fog), reflection off of water, or other particulate matter in the air. Ways around some of these line of sight issues will be discussed in this module.

Other issues with wireless: Wireless does have great advantages for rural and remote communities, as outlined. However, in addition to line of sight issues, there are technical issues with this technology that must be addressed in order for it to function well. Because the signals are not being sent through wires, security of the data becomes more of an issue, as there is greater potential for interception, and/or interference. Usage census and increased network security measures are required to monitor who is on the network. The potential for usage by non-network members is also increased. Additionally, because this technology generally relies on some form of outside antenna or access point, careful installation is of the utmost importance to ensure that the upfront technology investment is protected from the weather.

This wireless module will explain specifics for designing the wireless network, including what can be done to troubleshoot and eliminate problems. Installation of the equipment is covered, including pole, tower, and antennae installation, and the tools and equipment required to connect communities to the Internet using wireless technology are detailed.