enables Station 1 to move from the AP 1 signal coverage area to the AP 2 signal
coverage area without disconnecting from the network. The handover is achieved
transparently; the Station 1 user would not realize he had moved from AP 1 to AP 2.
The requirements for a roaming environment are:
a) Multiple APs with overlapping signal coverage (see “Multiple AP
Installation,”)
b) The APs must be configured to have the same domain name (SSID) and
security (WEP) settings (see “Config Window – Encryption Panel,”).
c) The mobile stations must have the same domain name (SSID) and security
(WEP) settings as the APs.
It is advisable that APs on different TCP/IP subnets be given different domain names
(SSIDs) to avoid roaming confusion (see the note below).
Note: For a mobile station to be able to move between APs without losing its
network link, the Roaming function must be enabled on the station (this is
automatic on some wireless LAN adapters), and the APs that the station
roams to must be configured with the same domain name (SSID). If a station
detects that the signal quality on the link to the current AP is poor, it will
search for an AP in the same domain with better signal quality and
automatically associate (establish a connection) with it. The station’s IP
address, however, will not change. A TCP/IP router will not route packets to a
mobile station that has associated with an AP on a different TCP/IP subnet. In
other words, if your network consists of two subnets connected by a router, a
mobile station may roam to a different subnet with the same domain name
(SSID) and then be unable to communicate with other network devices via
TCP/IP. To avoid this problem, you should assign different domain names
(SSIDs) to different TCP/IP subnets.
Outdoor Access Point
11
