Selecting A Different Antenna 11

Selecting A Different The standard detachable portable antenna supplied with the access point is a

Antennamulti-purpose antenna suitable for a variety of environments, including office LANs, physical plants, and factory floors. If your site has special requirements that might be served by different types of antenna, four optional antenna models are available, as shown below:

Model number

3CWE490

3CWE492

3CWE497

3CWE498

 

 

 

 

 

 

Design and type

Omnidirectional

Ceiling-mount

Ceiling-mount

Directional Panel

 

(fiberglass)

omnidirectional

hallway

 

(indoor/outdoor)

 

 

 

 

 

Frequency Range

2.400-2.4835 GHz

2300-2500 Mhz

2300-2500 Mhz

2300-2500 Mhz

 

 

 

 

 

 

 

 

 

Gain

4 dBi

 

2.5 dBi

 

4 dBi

 

8 dBi

 

 

 

 

 

 

 

 

 

 

VSWR across band

< 1.5:1

 

< 1.35:1

 

< 1.5:1

 

< 1.5:1

 

 

 

 

 

 

 

 

 

 

Distance (coverage)*

2100 feet

 

1800 feet

 

2100 feet

 

3600 feet

 

 

 

 

 

 

 

 

 

 

Effective Radiated Power

High:

159 mW

High:

112 mW

High:

159 mW

High:

398 mW

(ERP) @ different power

Medium:

50 mW

Medium:

36 mW

Medium:

50 mW

Medium:

126 mW

transmission settings**

Low:

13 mW

Low:

9 mW

Low:

13 mW

Low:

32 mW

 

 

 

 

 

Temperature range

-40°C to +80° C

-40°C to +80° C

-40°C to +71° C

-40°C to +80° C

 

 

 

 

 

Dimensions (inches)

10” (height)

4.25 (diameter)

2.6 x 1.8 x 0.2

5.1 x 4.7 x 1.5

 

 

 

 

 

 

 

 

 

Weight

5.34 oz.

 

8 oz.

 

2 oz.

 

8 oz.

 

 

 

Cable

A six-foot accessory cable (model 3CWE480) is required for each of these optional antennas. It

 

provides the transition from the SMA connector on the access point to the N-type connector

 

on the antenna. A 20-foot cable (model 3CWE481) is also available.

 

 

*Coverage varies depending on building construction.

**See “Setting Data Transmission Properties” on page 27 for information on selecting power transmission levels.

You can order any of the optional antennas by model number from the 3Com

Web site.

Omnidirectional Antenna

The fiberglass omnidirectional antenna (model number 3CWE490) is designed for use in harsh indoor environments. It can be centrally located on the ceiling to provide uniform coverage over a wide area.

This antenna features a built-in matching network that eliminates the need for a ground plane.

This antenna can be mounted on the ceiling by means of a standard ceiling-mount bracket. Before installing, ensure that access is available for cable routing.

This antenna does not have an electrical connection between the mask mount and the coaxial cable shield. However, adding a lightning arrestor will correct this situation by grounding the outer shield as recommended. Some arrestor designs provide over-voltage protection for the signal sent down the cable. If you use such

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3Com 11 Mbps manual Omnidirectional Antenna, Model number 3CWE490 3CWE492 3CWE497 3CWE498

11 Mbps specifications

3Com 11 Mbps was a pivotal product in the evolution of networking technology, paving the way for wireless communications as we know them today. Introduced in the late 1990s, this wireless LAN (Local Area Network) product utilized the IEEE 802.11 standard, which defined the protocols for wireless networking. Operating at a maximum data rate of 11 megabits per second, it offered users a revolutionary means of connecting devices without the constraints of physical cabling.

One of the main features of the 3Com 11 Mbps solution was its simplicity and ease of installation. Unlike traditional wired networks that involved intricate setups of cabling and switches, 3Com facilitated a swift deployment process. Users could set up a wireless network in minutes, allowing organizations to enhance their productivity without extensive infrastructure.

The technology behind 3Com 11 Mbps was based on Direct Sequence Spread Spectrum (DSSS) modulation. This approach spread the signal over a wider frequency range, which improved resistance to interference from other devices. The 2.4 GHz frequency band used by this network supported compatibility with various devices, making it a flexible option for businesses and homes alike.

In terms of security, 3Com incorporated Wired Equivalent Privacy (WEP), which aimed to provide a level of data confidentiality comparable to that found in wired networks. However, WEP was later found to have vulnerabilities, leading to the development of more secure protocols like WPA (Wi-Fi Protected Access) and WPA2 in subsequent technologies.

Another characteristic that distinguished the 3Com 11 Mbps system was its ability to support multiple devices simultaneously. With the emergence of wireless laptops, printers, and other peripherals, a single access point could service several users without significant performance degradation.

Ultimately, the 3Com 11 Mbps was a significant stepping stone in the development of wireless technology. It showcased the potential of wireless networking and set the standard for future innovations. Although much faster and more secure wireless technologies have since emerged, the legacy of 3Com 11 Mbps resides in the fundamental advancements it brought to the realm of connectivity, making it easier and more accessible for users around the globe.