Abstract:
A method and an apparatus for improving network performance by adjusting a bop size in a wireless sensor network are provided to minimize packet delay by re-using a beacon period based on the adjustment of the size of a BOP(Beacon-only Period). A ZigBee coordinator compares a value that a maximum hop count of a wireless network is divided into selected numbers with a length of BOP(Beacon-only Period)(S310). The ZigBee coordinator adjusts the size of the beacon period(S320), and applies the adjusted beacon period to the super frame and transmits the applied super frame(S330,S350).
Abstract:
An upsteam and downstream dynamic routing method using a beacon is provided to supply efficient dynamic routing by using beacon and join information of a MAC(Media Access Control) layer without using a route search packet. A node receives an address value from its parents node and shares address information with the parents node so that the node is joined with the parents node. The node determines whether a received data packet is broadcast(S201). When the data packet is not a packet to be broadcast, the node determines whether the node is a final destination node(S203). If the node is not a final destination node, the node transmits the data packet to the parents node based on the shared address information to set a routing route(S204).
Abstract:
A DACW(Distance. Adaptive Contention Window) adjusting apparatus in a wireless sensor network and a method thereof are provided to obtain more transmission opportunities in a node where the traffic bottleneck phenomenon occurs, thereby reducing the channel competition time and the amount of consumed energy. A DACW adjusting apparatus floods concerned packets so that a sink node can receive desired data from sensor target nodes(S10), calculates the hop count to relay the packets to a neighboring node(S20), establishes a path to the sink node by using routing metric(S30), compares the current traffic node with a pre-defined critical value based on the established path to determine whether the current state is congested(S40), if it is determined that the congestion does not occur, largely adjusting the value of a contention window(S50), and then if it is determined that the congestion occurs, adjusting the contention window value in small(S60).
Abstract:
An apparatus and a method for congestion control by using dynamic packet bursting in mobile Ad hoc networks are provided to increase the actual amount of traffic, not the simple concession of a bandwidth, thereby quickly solving congestion and reducing the packet transmission delay of the whole network, and improving its processing amount capacity. An apparatus for congestion control comprises the followings: an IP(Internet Protocol)(20) which manages Ad hoc routing through an Ad hoc routing protocol(10) in a mobile terminal; an MAC(Media Access Control)(40) based on IEEE(Institute of Electrical and Electronics Engineers) 802.11 which interacts with a data link layer; a monitoring unit(50) which determines a congestion state by monitoring the number of packets settled on an interface buffer and the number of active connections of each mobile terminal in the IP; and a resource allocating unit(60) which performs packet bursting by instructing the number and method of the packet bursting to the MAC if the congestion is recognized through the monitoring unit.
Abstract:
본 발명에 따르는 놀이치료를 위한 로봇 제어 시스템은, 놀이치료를 위한 시각적 및 청각적 및 촉각적 및 행동적 자극을 출력하는 로봇; 조작자에 의해 상기 로봇이 출력하는 자극에 따른 아동의 반응을 반응정보로서 입력받아 외부로 전송함과 아울러, 상기 조작자의 요청에 따른 자극을 출력하도록 하는 제어명령을 상기 로봇으로 전송하는 이동 단말기; 상기 이동 단말기가 전송하는 반응정보를 입력받아 상기 로봇이 출력하는 자극을 선호 또는 비선호 또는 무반응 하는지를 판단하고, 상기 자극의 선호 또는 비선호 또는 무반응 판단에 따라 다음 자극을 선정하고, 선정된 다음 자극을 출력하도록 하는 제어명령을 상기 로봇으로 전송하는 서버;를 구비하는 것을 특징으로 한다. 놀이치료, 로봇