Information Technology Reference
In-Depth Information
The Data Over Cable Service Interface Specifications (DOCSIS) protocol defines the cable
procedures that the equipment needs to support.
Figure 6-3 illustrates how a cable modem connects to the CMTS. The PC connects to the
TCP/IP network using PPP over Ethernet (PPPoE) or Dynamic Host Configuration Proto-
col (DHCP).
Remote Access
Internet Service Provider
Cable Modem
Termination
System (CMTS)
Cable Modem
PPPoE
Cable
DHCP
Cable Modem
Figure 6-3
Data over Cable
Wireless
Wireless as a technology uses electromagnetic waves to carry the signal between end-
points. Everyday examples of wireless technology include cell phones, wireless LANs,
cordless computer equipment, and global positioning systems (GPS).
Here are some examples of wireless implementations:
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.
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Wireless LAN:
WLANs have increased, too, in both residential and business envi-
ronments to meet the demands of LAN connections over the air. Commonly called
IEEE 802.11a/b/g/n or WiFi networks, 802.11n is now available and provides typical
data rates of 150 Mbps to 300 Mbps. The growing range of applications includes
guest access, voice over wireless, and advanced security and location-based services.
A key advantage of WLANs is the ability to save time and money by avoiding costly
physical layer wiring installations.
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Mobile wireless:
Consists of cellular applications and mobile phones. Most wireless
technologies, such as the second and third generations, are migrating to more digital
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