The four main requirements for a WLAN solution are as follows:
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High availability – High availability is achieved through system
redundancy and proper coverage-area design. System redundancy includes
redundant APs on separate frequencies. Proper coverage area design includes
accounting for roaming, automatic rate negotiation when signal strength
weakens, proper antenna selection, and the possible use of repeaters to extend
coverage to areas where an AP could not otherwise be used.
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Scalability – Scalability is accomplished by supporting multiple APs
per coverage area, which use multiple frequencies. APs can also perform load
balancing, if desired.
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Manageability – Diagnostic tools represent a large portion of
management within WLANs. Customers should be able to manage WLAN devices
through industry standard APIs, including SNMP and Web, or through major
enterprise management applications like CiscoWorks 2000, Cisco Stack Manager,
and Cisco Resource Monitor.
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Open architecture – Openness is achieved through adherence to
standards such as 802.11a and 802.11b, participation in interoperability
associations such as the Wi-Fi Alliance, and certification such as U.S. FCC
certification.
Other requirements are evolving as WLAN technologies gain popularity:
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Security – It is essential to encrypt data packets transmitted
through the air. For larger installations, centralized user authentication and
centralized management of encryption keys are also required.
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Cost – Customers expect continued reductions in price of 15 to 30
percent each year, and increases in performance and security. Customers are
concerned not only with purchase price but also with total cost of ownership
(TCO), including costs for installation.