User`s guide

Aironet Wireless Communications, Inc. 1-2 Confidential and Proprietary
standard. The PC4500/4800 WEP is capable of using 128 bit keys for additional security above the
802.11 standard which specifies the use of 40 bit keys.
System Configurations
The PC4500/4800 can be used in a variety of network system configurations. Aironet access points can
be used to provide a wireless connection to an ethernet or token ring wired network. The PC4500/4800
can be used in any of the following ‘standard’ system architectures:
• Point to point wireless connectivity (computer to computer transfer)
• Point to multi-point configuration (cash register price updates from server)
• Multiple terminal communications (workgroup discussion)
• Multiple terminal communication using an access point root unit (conference room discussion)
• Wireless mobile infrastructure using access points off a wired LAN (warehouse and retail
environments)
• Extended mobile infrastructure using repeaters (temporary parking lot sales)
An all wireless LAN is the simplest LAN configuration. These configurations are also referred to as peer
to peer or ad-hoc networks (802.11 uses the term IBSS – independent basic service set). In an all
Wireless LAN, using a peer to peer network operating system (such as Windows for Workgroups or
Windows 95), all devices equipped with the PC4500/4800 can be linked together and communicate
directly with each other.
Better coordination can be achieved by adding an access point to the configuration. The access point is
not required to be attached to any backbone LAN (such as an Ethernet LAN). It functions as a hub,
linking all workstations and devices together. This configuration is very similar to the peer to peer
network. The main difference is that the access point serves as the focal point for communications,
thereby increasing the effective communication range, since all PC4500/4800 nodes are not required to
be in direct communication range of each other. This configuration offers an added benefit of improved
PC4500/4800 power management for increased battery life and operation of the host device.
A micro-cellular network (infrastructure) can be created by placing two or more access points on a
backbone LAN. The wireless protocols and access point communications facilitate mobility by allowing
remote workstations to move from the domain of one microcell to another. The process is seamless and
transparent, and the connection to the file server or host is maintained without disruption. This
configuration is particularly useful with portable or mobile network workstations allowing these nodes to
maintain a session with an application executing on the wired network, even while moving about
(roaming). When a network is configured using multiple access points and/or repeaters, a mobile client
is automatically connected to the access point, which provides the best performance. This process is
referred to a seamless roaming.
Coverage Options
The system architecture options of the PC4500/4800 client devices and AP4500/4800 access points
provide for a variety of coverage alternatives and flexibility. The system can be designed to provide a
wide coverage area with minimal overlap (Figure 1.1) or coverage with heavy overlap (Figure 1.2) which
can improve system performance and add protection (redundancy) against downtime in the event of an
access point failure.