8.3 Location

   

Location is very important in fixed wireless environments for two reasons: accessibility and security. It is important to keep both of these objectives in mind when determining where to place both the antenna and the wireless modem.

Accessibility is generally the primary concern of fixed wireless Internet users, especially those using LMDS technology. If the antenna does not have clear line of sight to the ISP's WMTS, the connection is rendered useless.

Oftentimes, the need for line of sight access to the WMTS means that the antenna will have to be placed on the roof of the building, or on a pole several feet from the building. When the antenna is placed in remote areas like this, a cable is usually run to the modem, which is stored somewhere inside the building. In order to maximize accessibility, it is a good idea to work with the manufacturer of the wireless modem to determine the maximum distance that the modem can be from the antenna before unacceptable signal degradation begins to occur. [3] Obviously, it is not very effective to have a clear line of sight, but have the modem placed so far away that the signal fades.

[3] Signal degradation begins the moment the signal travels through the coupler to the RF cable.

NOTE

One way to improve wireless network performance is through the use of better cabling. Using better cabling, such as LMR-400 coaxial cable, can help reduce the signal degradation experienced .


A second concern is equipment security. Whenever possible, a wireless modem should be locked in the same closet as other routing equipment. As with routers and switches, an attacker who has direct access to a wireless modem can either sniff traffic directly from the modem, or can use the modem manufacturer's information to develop strategies for sniffing data.

Some companies will store the modem in the same location as the antenna, generally on a rooftop, as a way to keep the signal strength strong. From the roof, an Ethernet cable is run to the network. There is nothing inherently wrong with this, as long as proper security precautions are taken. The modem itself should be locked up in such a way that it is protected from both atmospheric conditions and from potential attackers . Someone lurking on the rooftop should not be able to determine the equipment manufacturer, and if possible, a fence should be built to enclose both the modem and the antenna.

As with any other piece of network equipment, default passwords on the modem should be changed, and the number of employees who have access to it should be limited.

   


The Practice of Network Security. Deployment Strategies for Production Environments
The Practice of Network Security: Deployment Strategies for Production Environments
ISBN: 0130462233
EAN: 2147483647
Year: 2002
Pages: 131
Authors: Allan Liska

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