Higher-Gain Antenna

 

Higher-Gain Antenna

Although you will not see a huge increase in the wireless coverage area when you replace your wireless router or hotspot gateway "rubber duck" antenna with a higher-gain one, it is a good way to maximize the coverage area for that particular infrastructure device. It is also a good way to increase the signal strength for places that are already covered, resulting in better performance, as depicted in Figures 12-1 and 12-2.

Figure 12-1. Example of Coverage with a "Rubber Duck" Antenna

[View full size image]

Figure 12-2. Example of Coverage with a High-Gain Antenna

[View full size image]

For example, say that a hotel manager sets up his hotspot gateway behind the front desk because that is where the Internet connection is. However, he wants to provide wireless Internet access to the people in the lobby and down the hall in the conference room. Hotel users often complain that they have a hard time keeping a connection to the hotspot in the conference room, and the typical signal strength is poor. He buys and hooks up a higher-gain antenna and then receives many fewer complaints about the coverage in the conference room, because the typical signal strength is now good.

Purchasing

Most wireless networking manufacturers offer high-gain antennas that work with their products. You can usually find out by visiting their website and browsing to their antenna section or viewing your product manual for compatible accessories.

You might be able to order the antenna directly from the manufacturer or a retailer. If you do not find it at local consumer electronics stores, you should try searching Internet stores, such as Amazon.com and Buy.com.

Table 12-2 lists the information about compatible high-gain antennas for the infrastructure devices used in the solutions discussed in this book.

Table 12-2. High-Gain Antennas for Infrastructure Devices Used in Solutions

Solution	Infrastructure Device	Compatible Antenna	Cost
Simple free access hotspot	Linksys Wireless-G Broadband Router Model #WRT54G	Linksys R-TNC Antenna (7 dBi) Model # HGA7T (sold in pairs) See Figure 12-3	$35$60
Advanced free access hotspot using ZoneCD	Linksys Wireless-G Broadband Router Model #WRT54G	Linksys R-TNC Antenna (7 dBi) Model # HGA7T (sold in pairs)	$35$60
Advanced free access hotspot using ZoneCD	Linksys Wireless-G Access Point Model #WAP54G	Linksys R-TNC Antenna (7 dBi) Model # HGA7T (sold in pairs)	$35$60
Join Boingo's hotspot network to provide paid access	Linksys Wireless-G VPN Broadband Router with a 5-dBi Antenna Model # WRV54G	Linksys R-SMA Antenna (7 dBi) Model # HGA7S	$36$50
Free or paid access and private network using hotspot gateway	D-Link Airspot Wireless G Public/Private Hot Spot Gateway with two 2-dBi Antennas Model #DSA-3200	D-Link 2.4-GHz Omnidirectional 7-dBi Indoor Antenna (need two) Model # ANT24-0700 See Figure 12-4	$35$50 each

Figure 12-3Figure 12-4

Figure 12-3. Linksys R-TNC 7-dBi Antenna (HGA7T)

Figure 12-4. D-Link 2.4GHz Omnidirectional 7-dBi Indoor Antenna (ANT24-0700)

Bear in mind that if you use a different brand from the infrastructure device for the antenna, you should buy an antenna that has the supported connector type.

Installation

To replace the antenna of your infrastructure device, you can usually remove the existing "rubber duck" antenna and connect the new antenna cable. Then you need to properly position the antenna and, if required, mount it. Generally, you get better performance if you position the antenna vertical to the ground. If the antenna has a separate base that you must mount, you can hide your infrastructure device, if desired, and place the antenna in a more visible location to obtain maximum range or coverage.