Abstract:
PURPOSE: A simulation apparatus based on a modeling and simulation framework in distributed cognitive radio networks is provided to simulate a hybrid access protocol. CONSTITUTION: A band selection unit (610) selects a spectrum band among a plurality of predetermined spectrum bands. A detection unit (620) detects virtual traffic that is transmitted to the selected spectrum band from a user node. If it is determined that the selected spectrum band is in an idle state by a result of detection of the virtual traffic, a packet transmission unit (640) transmits a packet through the selected spectrum band. A protocol selection unit (630) selects a spectrum access protocol corresponding to the aforementioned selected spectrum band among a plurality of predetermined spectrum access protocols. [Reference numerals] (610) Band selection unit; (620) Detection unit; (630) Protocol selection unit; (640) Packet transmission unit
Abstract:
PURPOSE: A spectrum selection method in a recognition wireless network is provided to independently select a spectrum and detect without additional control message by considering hardware restriction such as portability, mobility, power consumption and et cetera. CONSTITUTION: Whether a channel is an idle channel or not is detected in a time slot according to a predetermined channel selection method for a predetermined period consisting of the time slot. Communication is performed through the idle channel. An initial channel is assigned when the predetermined period passes. The predetermined channel selection method is a method detecting whether the next time slot is an idle channel or not with respect to the same channel when the detected time slot is an idle channel.
Abstract:
PURPOSE: A group unit dynamic channel assignment device for a cognitive wireless network is provided to assign spectrums to each group regarding the level of traffic generated by all the nodes within each group. CONSTITUTION: A group assignment unit (201) allocates a non-contention channel and a contention channel to each group. The non-contention channel is occupied by a plurality of groups. A first channel assignment unit (202) assigns a transmission channel of a first message to the non-contention channel. A second channel assignment unit (203) allocates the contention channel to transmission channels of a second message and a third message. [Reference numerals] (201) Group assignment unit; (202) First channel assignment unit; (203) Second channel assignment unit; (AA) First group; (BB) N-th group
Abstract:
PURPOSE: A group unit dynamic channel allocation method for a wireless network is provided to effectively use limited frequency resources by differently allocating a spectrum regarding the level of the traffic generated in all the nodes within each group. CONSTITUTION: A non-competition channel and a competition channel in a recognition wireless network are allocated to each of groups. The non-competition channel is monopolized with a plurality of the groups. The transmission channel of a first message in the group is assigned to the non-competition channel. The transmission channel of a second message and a third message is allocated to the competition channel. The first message demonstrates high QoS (Quality of Service). The first message is a message in which the delay time and a packet loss rate are not allowed.
Abstract:
본 발명에 따른 분산형 인지 무선 네트워크에서의 매체 접근 제어 방법은, 공통제어채널을 통하여 부사용자들 각각에게 미니슬롯이 할당되는 단계; 상기 부사용자들 각각이 복수개의 데이터채널들 중 자신에게 할당된 미니슬롯에 대응하는 데이터채널을 감지하고, 상기 공통제어채널을 통하여 자신에게 할당된 미니슬롯에서 상기 데이터채널의 감지 결과를 보고하는 단계; 및 소정의 이벤트가 발생하면 상기 공통제어채널을 통하여 상기 부사용자들 중 적어도 일부가 자신에게 할당된 미니슬롯을 이용하여 데이터채널의 사용을 위한 협상을 수행하는 단계를 포함하는 것을 특징으로 한다.
Abstract:
PURPOSE: A spectrum selection device for a recognition wireless network is provided to sense a spectrum without additional control messages by considering hardware limitations. CONSTITUTION: A channel allocating unit (201) allocates an initial channel to a recognition wireless network. When a set period comprising timeslots passes, the channel allocating unit allocates the initial channel again. A sensing unit (202) senses the channel of the time slot regarding the set channel selection method during the set period. The set channel selection method senses an idle channel from the time slot when the sensed time slot is the idle channel. [Reference numerals] (201) Channel allocating unit; (202) Sensing unit; (220) Communication unit