Data transfer device for a portable telephone

DETAILED DESCRIPTION An object of the present invention is to provide a data transfer device for a portable telephone which is capable of achieving efficient and reliable transfer of data and also minimizing the influence on vocal communication as well as the restrictions on the availability of added services.
To achieve the above object, there is provided a data transfer device for a portable telephone, to which data terminal equipment having a data transmitting/receiving function is connectable and which has a radio link provided with an information channel, a fast associated control channel and a slow associated control channel.
The data transfer device for a portable telephone comprises transfer data quantity measuring means for measuring a data quantity of transfer data input from the data terminal equipment, channel selecting means for comparing the data quantity measured by the transfer data quantity measuring means with a predetermined value and selecting one of the fast associated control channel and the slow associated control channel in accordance with a result of the comparison, data transfer means for sending the transfer data input from the data terminal equipment to the radio link by using the channel selected by the channel selecting means, and voice transmitting means for performing voice transmission by using the information channel, regardless of whether or not data transfer is performed by the data transfer means.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.