Abstract:
A method for resetting node position information in a wireless sensor network is provided to perform a function of a shadow anchor node and supply an anchor node to nodes without anchor nodes by resetting an initial position and confirming position information in the wireless sensor network. A method for resetting node position information in a wireless sensor network includes the steps of: setting an initial position based on an anchor node; receiving a position resetting message from the anchor node(S302); resetting the initial position by measuring a distance between adjacent nodes based on the anchor node(S306); and converting the anchor node into a shadow anchor node based on the reset position information, and broadcasting the reset position information and the shadow anchor information to other nodes(S310).
Abstract:
A time synchronization method in a wireless sensor network is provided to enable an upper node to offer backoff scheduling to lower nodes in the wireless sensor network having a hierarchical structure, so that each lower node can adjust time synchronization according to the backoff scheduling on the basis of local clocks. The first to fourth lower nodes receive synchronization packet data where time information broadcasted from an upper node is contained(S402). The first to fourth lower nodes start synchronization, and calculate backoff time by using self local clocks(S404). If the calculated backoff time comes(S406), the second and third lower nodes generate response packet data for the synchronization, and broadcast the generated data to the upper node(S408). If collision occurs when the response packet data are transmitted(S410), the corresponding lower nodes receive response packet data from other nodes to previously use the received data as self synchronization process start packet data, then conduct synchronization(S412).
Abstract:
본 발명은 타겟과, 일정한 영역 내에 위치한 타겟의 정보를 수집하는 센서노드들과, 타겟의 정보를 설정된 라우팅 경로를 이용하여 전달받는 싱크노드로 구성된 통신 시스템에서, 타겟의 정보를 전달하기 위해 센서노드로부터 싱크노드까지 라우팅 경로를 재설정하는 방안을 제안한다. 이를 위해 설정된 라우팅 경로로부터 타겟의 정보가 전달되지 않으면 타겟의 정보를 수집하고 있는 센서노드가 라우팅 요청 메시지를 브로드캐스팅한다. 설정된 라우팅 경로 상에 위치하고 있는 제1센서노드그룹의 제1센서노드에서 수신한 라우팅 요청 메시지에 포함되어 있는 정보와 제1센서노드로부터 일정 거리 내에 위치하고 있는 제2센서노드그룹의 제2센서노드에서 수신한 라우팅 요청 메시지에 포함되어 있는 정보를 비교한다. 비교에 의해 선택된 센서노드를 이용하여 라우팅 경로를 재 설정한다. 라우팅 요청 메시지, 라우팅 변경 메시지, 라우팅 응답 메시지, 홉 카운트
Abstract:
무선매체 접근방법이 개시된다. 본 발명에 따른 중재자로부터 브로드캐스트되는 동기신호에 의해 동기화 되는 무선 네트워크에서의 무선매체 접근방법은, a) 무선 네트워크에 참여하는 복수의 디바이스를 전송할 패킷의 응용 특성에 따라 무선자원의 확보를 위한 우선순위를 각각 결정하는 단계, b) 복수의 디바이스가 통신을 요청하면, 슈퍼프레임내 적어도 한 슬롯을 복수의 미니슬롯으로 분할하고, 우선순위에 따라 미니슬롯을 각각 복수의 디바이스중 어느 하나에 할당하는 단계 및 c) 동기신호에 할당된 미니슬롯에 대한 정보를 삽입하여 브로드캐스트하여, 할당된 미니슬롯 구간에서 할당된 미니슬롯을 확보한 디바이스가 우선적으로 통신하도록 하는 단계를 포함한다. 이에 의해, 노드 집적도가 높은 무선 개인영역 네트워크 환경에서 초기 리소스 확보시 많은 노드가 동시에 무선매체에 접근하는 경우 발생할 수 있는 충돌을 감소시킬 수 있다. 무선 개인영역 네트워크, 매체 접근, 슈퍼프레임, 지능형접근구간
Abstract:
무선네트워크에서 브로드캐스트 방법 및 그 방법을 사용하는 통신장치가 개시된다. 본 무선네트워크에서 브로드캐스트 방법은, 브로드캐스트 패킷을 수신하면 처음 수신된 패킷인지 여부를 판단하여, 처음 수신된 패킷인 경우에는 브로드캐스트 패킷을 저장한 후, 브로드캐스트 패킷을 리브로드캐스트 한다. 리브로드캐스트후에는, 인접 노드들 중에서 브로드캐스트 패킷이 중계된(relayed) 노드를 기록한다. 소정 시간 후에, 인접 노드들 모두에 브로드캐스트 패킷이 중계된 것으로 기록되어 있지 않으면, 다시 브로드캐스트 패킷을 리브로드캐스트하고, 모든 인접 노드에 브로드캐스트 패킷이 중계된 것으로 기록되어 있으며, 저장된 브로드캐스트 패킷을 폐기한다. 본 발명에 따르면, 링크 기반(link-based)에 의해 효율적인 브로드캐스트 방법이 제공된다.
Abstract:
A routing method comprising receiving a first packet, the first packet being broadcast for discovery of a route. A first backoff of the first packet is calculated based on a route cost of the first packet. The first packet is rebroadcast if a second packet is not received within the first backoff, the second packet being a duplicate of the first packet. A second backoff of the second packet is calculated based on a route cost of the second packet if the second packet is received within the first backoff. One of the first and the second packets is rebroadcast as a result of comparing the first backoff and the second backoff.
Abstract:
PURPOSE: A device and a method for setting a routing path in a scatternet are provided to set a routing path up to a destination device from a source device by using two steps only, and to designate a device of the routing path as a master device or a slave device according to the number of hops with the destination device, thereby reducing a time for setting the routing path while consuming the same power in devices configuring a scatternet. CONSTITUTION: Information for inquiring about the first radio resource used in each device configuring a piconet and information for requesting a routing path setting are generated as one packet. The packet is broadcasted to adjacent devices. The first radio resource includes address information and clock information. The second radio resources which can broadcast the generated packet are divided into at least two groups not to collide with each other. The packet is broadcasted by alternatively using the second radio resources included in the divided groups.
Abstract:
PURPOSE: A device and a method for setting a routing path in a sensor network are provided to reset a routing path by using sensor nodes located within a certain area and an existing set routing path, thereby reducing the number of transceived messages while reducing power consumption of the sensor nodes. CONSTITUTION: A sensor node receives an RREQ(Routing Request) message or an RREV message(S1100), and updates a stored routing table by using the message(S1102). The sensor node decides whether a received message is an RREQ message(S1104). If so, the sensor node decides whether the routing table is changed(S1106). If so, the sensor node decides whether the RREQ message is received from another sensor node(S1110). If so, the sensor node decides whether the sensor node is a final sensor node(S1112). If so, the sensor node generates an RREP(Routing Reply) message, and transmits the RREP message(S1114).
Abstract:
PURPOSE: A wireless communication equipment capable of controlling beacon intervals and a method therefor are provided to control time intervals between beacon slot column sections according to traffic amount within a piconet, thereby maximally improving performance of the piconet, even though the number of parked slaves is changed. CONSTITUTION: Beacon channel forming units(29,39) generate beacon slot column sections for the first period in a park mode state. Slot section operators(25,35) calculate the second period based on slot using rates and wake-up rates in slot sections so as to calculate the second period for the beacon slot column sections. Controllers(27,37) control the beacon channel forming units(29,39) in order to generate the beacon slot column sections according to the calculated second period. The slot section operators(25,35) calculate the longer second period than the first period, if a value subtracting a slot using rate of a just prior slot section from a slot using rate of a current slot section is more than the first predetermined value, and if a value subtracting a wake-up rate of the current slot section from a wake-up rate of the just prior slot section is more than the second predetermined value.
Abstract:
PURPOSE: A wireless communication method for preventing a mutual reference between wireless communication systems and an apparatus thereof are provided to prevent the mutual interference between the wireless communication systems by determining whether data are transmitted according to the state of a communication channel. CONSTITUTION: A measurement unit(61) measures a channel state of a transmission slot. A judgement unit(62) judges whether data are transmitted on the basis of the channel state of the transmission slot measured in the measurement unit(61). A control unit(63) outputs a signal for transmitting the data according to the judgement of the judgement unit(62). The measurement unit(61) measures the strength of a signal received in a channel used in the transmission slot.