Abstract:
PURPOSE: A method for allocating resources in a wireless network is provided to disperse a burden about a computative quantity which can focus on one node to several nodes, thereby enhancing the energy efficiency of the node. CONSTITUTION: Cluster headers are calculated according to the cluster after the cluster is formed. A node which comprises a wireless network determines whether oneself is a edge node or not. If the node is not an edge node, the node collects link information(301) with other nodes in cluster which oneself is included in. The collected ink information is transferred ot the cluster header of the node.
Abstract:
PURPOSE: A super frame structure and a beacon scheduling method for mesh networking are provided to support a mesh topology in a beacon mode and to enable easy adaptation of network environment change using a distribution-type beacon scheduling algorithm. CONSTITUTION: A join node performs beacon scanning(S201). The join node obtains neighboring mode beacon allocation information of a neighboring node(S203). The join node selects a non-allocated beacon slot(S205). A node which selects an own beacon slot transmits a beacon from the beacon slot periodically(S211).
Abstract:
PURPOSE: A time synchronization method for a multi-hop sensor network is provided to add a delay transmission temporal value to a beacon frame for reducing the collision of the beacon frame in a beacon mode, so that receiving nodes can perform exact time synchronization. CONSTITUTION: A transmission node performs CCA(Clear Channel Assessment) and backoff for preventing collision(S101). The transmission node creates a time stamp before transmission of a beacon frame and after time delay(S103). The transmission node adds a delayed temporal value and a time stamp value to the beacon frame. The transmission node transmits the beacon frame(S105). The delayed temporal value is the temporal value delayed by performance of backoff and CCA. The time stamp value comprises an interface delay value between an MAC(Media Access Control) layer and a PHY(Physical) layer and a modulation delay value in the PHY layer.
Abstract:
PURPOSE: An MAC(Media Access Control) system of a multi-hop sensor network is provided to prevent transmission delay caused by relatively long inactive duration for energy saving and the convenience of scheduling. CONSTITUTION: In the higher layer of a source device, MLME-EGTSinfo.request primitive is transmitted to MLME(MAC sub Layer Management Entity)(601). The MLME transmits an EGTS information request command to a destination device(602). The destination device confirms the reception of the EGTS(Extended Guaranteed Time Slot) information request command by transmission of an ACK(Acknowledgement) frame(603). The MLME of the destination device transmits a time stamp and an EGTS parameter to the source device(604). The source device transmits an ACK frame to the destination device(605). The MLME of the source device notifies a higher layer next to itself that the EGTS information request succeeds(606).
Abstract:
A method for estimating the distributed density and relative positions of sensor nodes which are randomly arranged and an apparatus therefor are provided to construct a wireless sensor network topology without the help of a network operator by constructing an autonomous topology depending on the local information between wireless sensor nodes which are randomly distributed. A location signal generator(810) periodically generates a signal showing the current location. A location signal detecting unit(820) detects the energy level and location signal holding time from the location signal received from neighboring sensor nodes. A distribution density estimating unit(830) estimates the distribution density of the neighboring sensor nodes within a reception available range based on the number of neighboring sensor nodes, energy level and location signal holding time. A location signal message transmitter(840) transmits a location signal message including the estimated distribution density to a reference sensor node.
Abstract:
A method and an apparatus for scheduling in a feedback based uplink are provided to allocate traffic transmission time according to the state of a terminal by enabling a base station to perform a scheduling operation based on an EQN(Explicit Queue length notification) message received from a correspondent terminal which has transmitted traffic. A first traffic is transmitted to a base station during a first traffic transmission time, and a second traffic is stored a queue(S170). Before the initiating state of the next service section, it is judged whether or not the second traffic stored at the queue can be processed during the first traffic transmission time(S190). A message requesting the allocation of the second traffic transmission time is generated(S210). The message including the information of the second traffic transmission time is received from the base station.
Abstract:
A method and an apparatus for predicting wired/wireless network traffics through probabilistic traffic characteristic estimation are provided to model characteristics of dynamically-changed traffics, and extract probabilistic characteristics of the traffic from limited sampling data, thereby probabilistically predicting effects of traffics, applied to a specific flow or a specific link, on service quality of the other flow or link for providing services within a network. A frame of a flow flowed into a variation band traffic within a preset time in wired/wireless networks is sampled(S601,S602). A probability distribution function for a continuous function corresponding to a histogram of continuous frame duration extracted through the sampling, continuous frame duration configured from frame pause period data and continuous frame appearance period is calculated(S609). Through the flow frame sampling increase, the probability distribution function of the continuous frame duration and the continuous frame appearance period is modified. Based on the modified probability distribution function, the traffic is predicted.
Abstract:
A method for improving TCP(Transmission Control Protocol) performance by congestion window limit is provided to provide an efficient service and a stable multimedia service by maintaining a congestion window at such a size as not to generate packet accumulation and preventing an unnecessary loss for checking an available bandwidth to thus obtain optimum performance and stable characteristics regardless of a buffer size. When a network connection is established(101), it is checked whether a service is a fixed bandwidth service(102). When the service is a fixed bandwidth service, a maximum congestion window is preferentially and quickly set by using an available bandwidth prediction method(103). A minimum round trip delay is calculated(104) and an effective optimum congestion window is calculated by using the calculated minimum round grip delay value(105). The calculated optimum congestion window is applied to control a TCP congestion window(106). When an available band increases while the congestion window is being applied(107), the maximum congestion window is updated by obtaining an additional band(108).
Abstract:
본 발명은 유선 네트워크에서 전송 노드의 물리적인 위치를 용이하게 파악하고 네트워크상의 악성 공격에 강한 보안성이 있는 전송 노드의 주소 체계 구조 및 이 전송 노드의 주소 체계 구조를 기반으로 한 전송 노드의 주소 할당 방법을 제공하고, 유선 네트워크에서 라우팅을 설정하고 패킷 데이터를 전송할 때, 전송 노드의 패킷 헤더 분석 시간을 줄이고 빠른 라우팅을 할 수 있도록, 전송 노드의 주소 체계 구조를 이용한 라우팅 헤더 설정 방법 및 패킷 데이터 전송 방법에 관한 것으로, 본 발명에 따른 전송 노드의 주소 체계 구조는, 네트워크의 최하위 레벨에 해당되는 레벨 영역의 전송 노드의 식별 정보부터 네트워크의 최상위 레벨에 해당되는 레벨 영역의 전송 노드의 식별 정보까지 물리적으로 연결된 각 레벨에서의 전송 노드의 식별 정보를 순차적으로 포함하고, 각 레벨에서의 전송 노드의 식별 정보는 동일한 길이를 갖는다.
Abstract:
1. 청구범위에 기재된 발명이 속한 기술분야 본 발명은 동기식 이더넷에서의 프레임 동기 방법 및 클럭 발생 장치에 관한 것임. 2. 발명이 해결하려고 하는 기술적 과제 본 발명은 클럭 동기가 이루어지지 않은 네트워크에서, 프레임의 시간 간격을 일정하게 유지시키는 프레임 계수기를 일치시키고 그 후 수신되는 프레임 계수기의 오차를 이용하여 송수신단의 클럭을 일치시킴으로써, 동기 서비스가 가능하도록 하는 프레임 동기 방법을 제공하는데 그 목적이 있음. 3. 발명의 해결방법의 요지 본 발명은, 프레임 간격을 일정하게 유지시키는 프레임 계수기를 이용한 송신 노드와 수신 노드 간의 프레임 동기를 위한 방법으로서, 수신 노드가 송신 노드와 프레임 계수를 포함하는 동기식 패킷을 송수신하여, 자신의 프레임 계수를 송신 노드의 프레임 계수에 일치시키는 프레임 계수 일치단계; 프레임 계수를 일치시킨 후 송신노드와 프레임 계수를 포함하는 동기식 패킷을 송수신하여, 송신 노드의 프레임 계수와 자신의 프레임 계수의 오차를 추출하고 그 프레임 계수 오차 정보를 이용하여 자신의 프레임 계수를 보정하는 프레임 계수 보정단계; 및 상기 프레임 계수 오차 정보를 클럭 발생 장치의 입력 기준 신호로 사용하여 보정된 베이스 클럭을 생성하는 베이스 클럭 보정단계를 포함함. 4. 발명의 중요한 용도 본 발명은 이더넷 네트워크 시스템 등에 이용됨. 이더넷, 클럭, 동기, 프레임