Abstract:
본 발명은 2세대 모뎀용 매체접속제어 통신 프로토콜 선택방법에 관한 것이다. 본 발명에 따른 2세대 모뎀용 매체접속제어 통신 프로토콜 선택방법은, a)임의의 선박국에 의해 해상 통신에서 사용되는 규정된 주파수 범위대의 두 개의 주파수 f1, f2 중 일측의 주파수를 스캐닝하여 신호가 검출되는지의 여부를 판별하는 단계; b)상기 판별에서 신호가 검출되면, 상기 두 개의 주파수 f1, f2 중 타측의 주파수를 스캐닝하여 신호가 검출되는지의 여부를 판별하는 단계; c)상기 단계 b)의 판별에서의 신호 검출 여부에 따라, 매체접속제어를 선택하기 위해 싱글홉 모드 또는 멀티홉 모드의 통신 네트워크를 설정하는 단계; 및 d) 상기 설정된 싱글홉 모드 또는 멀티홉 모드에 따라 CS-TDMA 또는 EASO-TDMA의 매체접속제어 프로토콜을 선택하는 단계를 포함한다. 이와 같은 본 발명에 의하면, 주어진 물리적 제원에서 싱글-홉(single-hop) 모드와 멀티-홉(multi-hop) 모드 중 어느 하나의 모드를 육상국과 선박국, 선박국과 선박국 간에 설정하고, 그를 바탕으로 대응하는 매체접속제어 프로토콜을 적절히 적용함으로써 해상통신을 원활하게 수행할 수 있다.
Abstract:
The present invention relates to a medium access control method with an enhanced ad-hoc self-organizing time division multiple access method for a base station, more particularly, to a medium access control method with an enhanced ad-hoc self-organizing time division multiple access method designed with an enhanced ad-hoc self-organizing time division multiple access (EASO-TDMA) communication method which is to improve the disadvantage of a communication method due to an ad-hoc self-organizing time division multiple access (ASO-TDMA) which is previously used and is to more practically correspond to environment change of marine communication.
Abstract:
PURPOSE: A method for communications of a marine moving body ad hoc network and a node thereof are provided to perform routing and medium access control (MAC) in one algorithm in consideration of a marine communications environment. CONSTITUTION: A communications mode setting part (100) sets up a communications mode for transmitting and receiving a message based on whether there is the other node around a node or not and an available channel situation of the node. A communications control setting part (200) comprises a communications activation part and a communications deactivation part. The communications control setting part performs set-up for transmitting and receiving the message based on reception target information included in the message and the type of the message. A message transceiver (300) transmits and receives the message according to the set communications mode and communications control set-up. [Reference numerals] (100) Communications mode setting part; (110) Carrier wave detecting unit; (130) Node identifier data storing unit; (150) Transceiving mode setting unit; (200) Communications control setting part; (210,230) Communication activating unit; (300) Message transceiver
Abstract:
PURPOSE: An apparatus and method for transmitting additional information in a preamble in a packet data communication using differential modulation are provided to increase a data transfer rate by rotating the preamble, which is predetermined according to the classification of a packet, by phase. CONSTITUTION: A phase rotator(110) outputs a phase rotation amount corresponding to additional information to be applied to a transmission target packet. A transmission multiplier(120) multiples a phase rotation amount, which is outputted from the phase rotator, and the preamble to be transmitted. A symbol mapper(130) converts a header and payload data to be applied to the transmission target packet into a symbol. A multiplexer(140) selectively outputs an output signal of the transmission multiplier and an output signal of the symbol mapper through an output terminal. A differential symbol converter(150) converts a symbol string outputted from the multiplexer using preset differential modulation. [Reference numerals] (110) Phase rotator; (130) Symbol mapper; (140) Multiplexer; (150) Differential symbol converter; (AA) Preamble symbol row; (BB) Packet additional information; (CC) Header and payload