Wireless Middleware Services
 
Wireless
Middleware Services
Security
Security is essential in a wireless system. As wireless
communications cannot be physically secured, the needs of wireless access
present a new series of challenges. Wireless access to enterprise systems puts
not only the client device, but also the data, well beyond the physical control
of the organization. Sniffing of data traffic can be done without any risk of
detection, over a much wider range of locations. Furthermore, the client device,
in the case of a cell phone or PDA, is even easier to steal than a laptop
computer, with the additional loss of security. Compromise of the wireless
client thus poses a double threat to data: the remote access to data the device
enables, and immediate access to the downloaded data stored within it. The
wireless middleware can thus incorporate a key encryption security mechanism as
described elsewhere.
Compression
The low bandwidth in a wireless link requires that the
volume of data being transmitted be kept as small as possible. For this reason,
data should be compressed from the client to the server and from the server to
the client. This desire for efficiency contrasts with the processing requirement
on the client side. If the client is a laptop computer, then it can have
adequate processing power to decompress the data; however, if the client device
is a PDA, the amount of processing power available currently is inadequate to
decompress large amounts of data in real time.
As optimal-compression algorithms are data specific, the
compression algorithm to be used will vary on the type of data. For example,
text compression, picture compression, Java class compression, and XML
compression, all use specific, different algorithms. The best the middleware can
do is to have a library of common compression algorithms it can use to compress
uncompressed data depending on the type. Alternatively, the problem of
compression can be regarded as an application design consideration and be left
to the application developer to elect whether to compress the data or not. The
middleware will then only pass data it is given and not attempt to perform any
compression.
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