User's Manual

Teklogix 9150 Wireless Gateway User Manual 9
Chapter 1: Introduction
IEEE 802.11b Protocol
1.5.1.1 Inter-Access Point Protocol (IAPP)
The Inter-Access Point Protocol (IAPP) is an extension to the IEEE 802.11b proto-
col. IAPP facilitates roaming of mobile stations across different Basic Service Sets
(see Note below) and specifies how access points communicate with each other.
Note: A Basic Service Set (BSS) is a set of stations (terminals) controlled by a
single coordination function, in this case by the 9150 Wireless Gateway
functioning as an access point within the terminals’ radio coverage area.
In a multiple-9150 system, IAPP informs the other 9150 Wireless Gateways when a
new 9150 becomes active, and enables the awareness of the 9150s of each other.
With IAPP, an IEEE 802.11b system can operate on one or more channels, with
terminals moving between the 9150s. Although each terminal is associated with one
9150, it can re-associate with another 9150 to maintain uninterrupted communica-
tions. The newly-associated 9150 will receive the terminal’s data frames and pass
them onto the LAN. Returning frames are no longer accepted by the original 9150,
which has disassociated from that terminal. The returning frames are now accepted
by the newly-associated 9150 and passed over the RF to the terminal.
1.5.1.2 Psion Teklogix’ 802.IQ Protocol
802.IQ is a Psion Teklogix proprietary optimized protocol that enables terminals to
operate on a wireless LAN in a network that supports both TCP/IP and 802.IQ pro-
tocol simultaneously. 802.IQ protocol is available in two versions: 802.IQv1 and
802.IQv2. The 9150 can support both versions of the protocol at the same time (ter-
minals must use only one).
802.IQv1 protocol is a wireless LAN routing scheme that provides greater perfor-
mance in an 802.11b wireless network than is possible with TCP/IP routing. The
9150 bridges the 802.IQv1 wireless and TCP/IP wired networks. A terminal can
communicate with the 9150 access point using either TCP/IP or 802.IQv1 protocol,
which makes possible a system with dual-operability.
802.IQv2 protocol is an enhanced version of the 802.IQv1 protocol that transports
packets over the UDP layer. It provides all the 802.IQv1 functionality, with the added
features of software upgrade capability over RF, the ability to add third-party access
points between controllers and terminals, and integration into the mapRF system if desired.
For detailed information on configuring the 9150 as an 802.IQv1 access point, see
“802.IQ Version 1 Configuration Menu” on page 64. For information on configuring
the 9150 as an 802.IQv2 mini-controller, see “802.IQ V2 Features Menu” on page
192. Please see Figure 1.4 on page 10 for a generalized system diagram.