Wireless

Wireless as a technology uses electromagnetic waves to carry the signal between endpoints.

Everyday examples of wireless technology include cell phones, wireless LANs, cordless computer equipment, and satellite television.

Here are some examples of wireless implementations:

■ Mobile wireless—Consists of cellular applications and mobile phones. Most wireless technologies such as the second and third generations are migrating to more digital services to take advantage of the higher speeds. Mobile wireless technologies include GSM, GPRS, and UMTS:

— GSM—Global system for mobile communications. A digital mobile radio standard that uses Time-Division Multiplex Access (TDMA) technology in three bands— 900, 1800, and 1900 MHz. The data transfer rate is 9600 bps and includes the ability to roam internationally.

— GPRS—General Packet Radio Service. Extends the capability of GSM speeds from 64 kbps to 128 kbps.

— UMTS—Universal Mobile Telecommunications Service. Also known as 3G broadband. Provides packet-based transmission of digitized voice, video, and data at rates up to 2.0 Mbps. UMTS also provides a set of services available to mobile users, location-independent throughout the world.

■ Wireless LAN—WLANs have increased too in both residential and business environments to meet the demands of LAN connections over the air. Commonly called IEEE 802.11a/b/g or Wi-Fi wireless networks. Currently, 802.11n is in development and provides typical data rates of 200 Mb/s. The growing range of applications includes guest access, voice over wireless, and support services such as advanced security and location of wireless endpoints. A key advantage of WLANs is the ability to save time and money by avoiding costly physical layer wiring installations.

■ Bridge wireless—Wireless bridges connect two separate wireless networks, typically located in two separate buildings. This technology enables high data rates for use with line-of-sight applications. When interconnecting hard-to-wire sites, temporary networks, or warehouses, a series of wireless bridges can be connected to provide connectivity.

Figure 5-7 shows bridge wireless and wireless LANs.

Figure 5-7 Wireless Implementations

Figure 5-7 Wireless Implementations

NOTE Additional information on wireless LANs is provided in Chapter 4, "Wireless LAN Design."

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