CHAPTER 6. PHONE INTERFACE

6.1 INTRODUCTION

A. Layer

I519 is complex terminal that is physically divided into PDA side and Phone side. PDA entirely relies on Phone side for the functions related to phone. To connect the two sides, DPRAM element is used, which is the simplify characters of Dual Port RAM. It has two ports and each port is assigned to both sides respectively for communication. DPRAM driver makes the two sides interchange resource messages that are made by following the communication protocol known to both sides. Phone server, which is PDA side application, refines and standardizes the message taken from DPRAM and sends it to the applications that want to communicate with phone. The layer can be divided into 6 from the applications that want to communicate with phone to DPRAM driver that sends resource message to phone.

It is the layer composed of the applications that want to communicate with phone. The applications connect with ID that is registered in TAPI, request, and take response through call back function. Those are identified and restricted by special ID that is registered in TAPI.

It is the library that is offered for the applications that want to interface with phone. Through this, applications deliver their ID and request phone functions and take response of the function.

It controls the applications that are connected by TAPI and sends the responses relevant to their requests.

It implements the protocol that is to interface with phone and it interchanges resource data directly with DPRAM. The protocol for communicating with PDA and Phone (IPC-Inter Process Command) is implemented.

It is for Network applications that use Ethernet. It switches phone to data communication mode and forms virtual Ethernet through PPP demon. Through this, network applications can do mailing, WEB browsing, WAP browsing, etc. using TCP/IP, UDP.

It is the module that controls DPRAM hardware. It takes charge of interchanging resource data, which is defined as protocol, with phone.