Wavecom W51PC, User Manual

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Glossary of Terms User Manual W51PC DCOM Interface V1.1
The addition of the "D" to COM was due to extensive use of DCE/RPC -
more specifically Microsoft's enhanced version, known as MSRPC.
In terms of the extensions it added to COM, DCOM had to solve the
problems of
Marshalling - serializing and deserializing the arguments and return val-
ues of method calls "over the wire".
Distributed garbage collection - ensuring that references held by clients
of interfaces are released when, for example, the client process crashed,
or the network connection was lost.
One of the key factors in solving these problems is the use of DCE/RPC
as the underlying RPC mechanism behind DCOM. DCE/RPC has strictly
defined rules regarding marshalling and who is responsible for freeing
memory.
DCOM was a major competitor to CORBA. Proponents of both of these
technologies saw them as one day becoming the model for code and
service-reuse over the Internet. However, the difficulties involved in get-
ting either of these technologies to work over Internet firewalls, and on
unknown and insecure machines, meant that normal HTTP requests in
combination with web browsers won out over both of them. Microsoft, at
one point, attempted and failed to head this off by adding an extra http
transport to DCE/RPC called
DTD
Can accompany a document, essentially defining the rules of the docu-
ment, such as which elements are present and the structural relationship
between the elements. It defines what tags can go in a XML document,
what tags can contain other tags, the number and sequence of the tags,
the attributes a tag can have, and optionally, the values those attributes
can have.
RGB
A color perceived by the human eye can be defined by a linear combina-
tion of the three primary colors red, green and blue. These three colors
form the basis for the RGB-colorspace.
Unicode
Unicode is a character code that defines every character in most of the
speaking languages in the world. Although commonly thought to be only
a two-byte coding system, Unicode characters can use only one byte, or
up to four bytes, to hold a Unicode "code point" (see UTF-8 and UTF-16).
The code point is a unique number for a character or some character as-
pect such as an accent mark or ligature. Unicode supports more than a
million code points, which are written with a "U" followed by a plus sign
and the number in hex; for example, the word "Hello" is written U+0048
U+0065 U+006C U+006C U+006F.
UTF-16
This is a fixed-length character encoding for unicode. It is able to
represent any universal character in the Unicode standard. UTF-16 uses
two bytes per character.