Sungkyunkwan University

Samsung Electronics Co., Ltd.

Hee-Yong Youn

Kyung-Tae Kim

Young-Jip Kim

Young-Seop Han

Hyun-Chul Lee

Jin-Woo Jeon

Kyu-Ho Lee

Sung-jin Choi

A method and apparatus perform channel scanning in a wireless communication system. A signal intensity of an Access Point (AP) is compared with a scanning threshold, when the AP signal intensity not less than the scanning threshold, a channel scanning schedule list is generated in consideration of a scan time based on a passive channel scan scheme and a scan time based on an active channel scan scheme. The channel scanning is performed every channel scanning time, according to the channel scanning schedule list.

Method and apparatus for channel scanning in a wireless communication system

A system for effectively pre-distributing keys for a distributed sensor network is disclosed, The system includes: a plurality of sensor nodes, each of which has a sensing function, a calculation function, and a wireless communication function; and a base station which is connected to the sensor nodes over a wireless network, receives data from the sensor nodes, acts as a data central station, and distributes keys for inter-sensornode security authentication to the sensor nodes. A key management unit contained in the base station, generates a set of the sensor nodes used for security authentication between the sensor nodes, decomposes the set of the sensor nodes into a plurality of matrices, distributes the matrices to the sensor nodes, and allows the sensor nodes to search for a common private key required for the security authentication using the received matrices. Therefore, the system can always search for a common private key between the sensor nodes.

System and method for effectively pre-distributing key for distributed sensor network

An apparatus and method are provided for transmitting data in a station of a wireless local area network (LAN) system. In the apparatus, a data queue stores transmission data, and a data processor processes data output from the data queue. A radio frequency (RF) module up-converts a signal output from the data processor to a frequency band of the wireless LAN system, and transmits the up-converted signal as an RF signal. A scheduler performs scheduling such that a specific stepping index decreases each time a backoff time reaches '0' so as to determine whether to transmit the data, and the data is transmitted when both the stepping index and the backoff time reach '0'. A backoff stepping generator determines an initial value of the stepping index within a predetermined range.

Apparatus and method for transmitting data in a wireless local area network

Growing community of inventors

Seongnam-si, South Korea

Hee-Yong Youn