Publication Number 53719. Issue 3, April 2012
SERVICE MANUAL FOR THE 13754 TGX150 INTERNAL RLAN TYPE A/B SC ETM
Page 7
3
GENERAL DESCRIPTION
3.1
WHAT IS RADIO LAN?
A wireless local area network (LAN) is a flexible data communications system implemented
as an extension to, or as an alternative for, a wired LAN. Using radio frequency (RF)
technology, wireless LANs transmit and receive data over the air, minimizing the need for
wired connections. Thus, wireless LAN’s combine data connectivity with user mobility.
In a typical wireless LAN configuration, a transmitter / receiver (transceiver) device, called an
(Access Point), connects to the wired network from a fixed location using standard cabling.
At a minimum, the access point receives, buffers, and transmits data between the wireless
LAN (Internal Radio LAN in the ETM) and the wired network infrastructure. A single
access point can support a small group of users and can function within a range of less than
one hundred to several hundred feet.
3.2
WHAT THE RADIO LAN SYSTEM DOES?
All vehicles are fitted with Internal Radio LAN ETM’s mounted in a convenient position,
depending on the vehicle.
As the driver proceeds along his route, details of all tickets issued or processed by the ticket
machine are stored in the memory of the module located inside the ticket machine. Typically,
the module will record information such as the number, value, and type of each ticket issued.
At the end of his shift, the driver returns the bus to the depot. The Depot is the location where
all information from the day’s transactions can be downloaded and analysed.
To do this the depot consists of wireless Radio LAN access points and (Depot readers
connected to Depot computers). As the bus comes into range of the depot the module
information is transmitted from the bus to the depot over the Radio LAN. The depot reader
and the stored information are read into the computer to which the depot reader is connected.
When taken together with information from all the other buses over a period of time, a study
of this accumulated information enables the bus company to determine the best and most
efficient way of operating their fleet of buses.
