Electronics and Telecommunications Research Institute

Don-Sung Oh

Dong-jin Shin

Seung-Chan Bang

Hyun-Kyu Chung

Il-Gyu Kim

Young-Dae Lee

A group service providing method and apparatus suitable for use in a wireless communication system. A group registration method for providing a group service to a master terminal and a slave terminal, the group registration method may comprise receiving and storing subscriber profile information of the master terminal from an associated communication network server in response to a group service registration request from the master terminal; generating a group related to the group service registration request and a group key corresponding to the generated group and transmitting to the master terminal a group generation completion message including the group key; receiving and storing subscriber profile information of the slave terminal dependent on the master terminal from the communication network server; and transmitting the group key to the slave terminal with reference to the subscriber profile information of the slave terminal.

Apparatus and method for providing group service in wireless communication system

The invention once stores PCM data to a memory and after a predetermined time is elapsed, reading in again and making to output whereby makes to delay the PCM data. The invention comprises a memory for once storing a PCM data converted to parallel, a delay time setting circuit for setting a delay time of PCM data, and a comparator and control circuit for comparing a setting value from the delay time setting circuit and a high order 10 bits writing address of the memory and thereby providing an address and control signal for either initiating a high order 10 bits reading address of the memory or else for writing or reading to the memory.

Delay circuit of PCM data

The invention is a method for controlling an echo canceller circuit including a data storage for storing a program for processing digital signals to cancel an echo in PCM encoded voice data, a plurality of digital signal processors each having a reset terminal and which are downloaded with the program which is executed by the plurality of digital signal processor to carry out removal of the echo in the PCM encoded voice data, and a one chip controller for performing control functions of the echo canceller. The method comprises the steps after completion of initialization of the one chip controller, controlling the reset terminals of the digital signal processors to maintain all of the digital signal processors in reset state; releasing one digital signal processor from the reset state and downloading the program to the one released digital signal processor from the data storage; and the released one digital signal processor processing the PCM encoded voice data with the program to remove the echo from the PCM encoded voice data.

Growing community of inventors

Daejeon, South Korea

Don-Sung Oh