Data transfer device for a portable telephone

摘要

A data transfer device for a portable telephone which device is capable of achieving efficient and reliable transfer of data and minimizing the influence on vocal communication and restrictions on the availability of added services. When data is to be transferred from data terminal equipment connected to a portable telephone to another data terminal equipment connected to a portable telephone at a remote side of a network during vocal communication, transfer data quantity measuring unit measures the data quantity of the transfer data. Channel selecting unit compares the measured data quantity with a predetermined value, and selects one of a fast associated control channel and a slow associated control channel in accordance with the result of comparison. Using the channel selected by the channel selecting unit, data transfer unit sends the transfer data input from the data terminal equipment to a radio link.