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8.4.7 Design
This chapter should be read by anyone who needs an overview of EPOC’s communications and
networking facilities. It consists of three parts.
The first part outlines the key concepts underlying EPOC communications, which have been
designed specifically for mobile users and mobile devices. The middle section describes the
individual components from the user’s point of view, starting from the low level device drivers
and servers and ending with EPOC’s communications applications. The chapter concludes with a
more detailed description of how the various components interlock to provide EPOC applications
with dial-up networking facilities.
8.4.7.1 Introduction
EPOC is a powerful software platform for wireless information devices. Its general aims are to
provide compact, fast and fully-featured applications to the users of ROM-based wireless
information devices; to support Symbian’s licensing strategy by allowing the component mix to
be tailored for different EPOC devices; and to provide a basis for future application and
component development. Among the currently available communications components are:
•
serial and infrared device drivers
•
serial communications server
•
sockets server
•
infrared protocol suite, including IrDA, IrCOMM and IrObex
•
TCP/IP with dial-up support
•
PPP with callback support
•
Internet mail, including SMTP, POP3 and IMAP4
•
support for MIME attachments
•
fax send and receive
•
SMS send and receive
•
web browsing
•
PC connectivity and synchronisation
•
end-user applications for terminal emulation, web browsing, and integrated messaging
Since Symbian licenses EPOC for a range of devices encompassing both smartphones and
communicators, not all components are necessarily suitable for inclusion in all platforms.
8.4.7.2 Design goals
EPOC’s communication components have to be exceptionally flexible, in order to cope with the
challenges inherent in mobile ROM-based computing. It is critically important that end-users are
able to tailor the active mix of components on any individual machine quickly, easily, and safely,
without restarting or rebooting, and without losing any data.
The highly mobile nature of wireless information devices means that the services and devices that
they find readily available are likely to change as they move from place to place.
•
EPOC has been designed for machines which use dial-up connections to Internet Service
Providers (ISPs) . Users can switch between ISPs, phones, and modems with minimal
difficulty, and can then dial out reliably from wherever they are. No substantial
reconfiguration is needed for each new location.
•
EPOC is also designed to cater for the fact that as machines move about, any applications
providing services such as connectivity, synchronisation, and printing may need to
support different hardware and software at each location.
The fact that wireless information devices are ROM-based means that special care has had to be
taken to allow for the fact that communications protocols and standards continually evolve.
•
EPOC is designed to allow the installation of new features such as additional protocols as
they are needed. The fact that both the operating system and the core applications are
built into the ROM does not mean that machines have to be reprogrammed or returned
for service if an application has to be enhanced to access a service that did not exist when
the machine was built.
