Abstract:
PURPOSE: An apparatus and method for optimizing transmission power of a wireless private simple network are provided to enable nodes to reduce transmission power consumption while maintaining a suitable level of communication quality by performing a protocol for optimizing transmission power. CONSTITUTION: Reference transmission power between a master and a slave is determined by comparing connection information received from the slave with allowable sensitivity(S440). Transmission power between the master and the other remaining slaves constituting a PAN(Personal Ad-hoc Network) is optimized(S480).
Abstract:
PURPOSE: An apparatus and method for optimizing transmission power of a wireless private simple network are provided to enable nodes to reduce transmission power consumption while maintaining a suitable level of communication quality by performing a protocol for optimizing transmission power. CONSTITUTION: A communicating unit(10) transmits or receives a data packet in the air. A power measuring unit(20) measures power of the data packet received through a receiver(4). A power adjusting unit(30) adjusts transmission power of a transmitter(2). A memory(50) stores a transmission power value with respect to each slave. A link quality measuring unit(32) measures link quality with respect to a specific slave based on the measured reception power of the data packet and a reception state parameter of the data packet. A link quality comparing unit(34) compares the reception link quality and pre-set reference link quality and obtains a difference. A power adjusting value determining unit(36) determines whether to increase or reduce power to be transmitted to the slave according to the comparison result value. A controller(40) broadcasts a packet with content requesting the slave to adjust transmission power according to the determined power adjustment value through the transmitter(2).
Abstract:
A method for transmitting data in a centralized data communications system using a carrier sense multiplexing access (CSMA) method is provided. The data transmission method uses a backoff number control in a centralized data communications system formed with an access point and stations, the method comprising (a) receiving a multi-poll message containing backoff numbers to be assigned to each station by the access point; (b) setting the backoff numbers of the multi-poll message to the backoff numbers of the stations; and (c) counting down the set backoff numbers and transmitting data. Each station that desires polling registers a station ID and a polling cycle, sets a backoff number contained in a multi-poll message, counts the backoff number, and if the backoff number becomes '0', transmits data such that contention between stations can be prevented. The data transmission method can be applied for controlling media access of a wireless LAN or Home PNA such that time-limited services can be supported. Also, with simple implementation, the method can be easily applied to existing systems such that the method can support real time service in low priced systems.
Abstract:
PURPOSE: A method is provided to effectively support a real time traffic and ensure a backward compatibility, while differentiating channel access regions between the real time terminal and non-real time terminal. CONSTITUTION: A method comprises a step(1000 to 1200) of constructing a first or a second competitive window in accordance with whether the corresponding terminal is a real time terminal or a non-real time terminal during channel access; and a step(1300,1400) of permitting the real time terminal to gain an access to the channel prior to the non-real time terminal by including a predetermined offset value to the second competitive window of the non-real time terminal in case where the real time terminal and the non-real time terminal request a channel access at the same time.
Abstract:
PURPOSE: A method of transmitting data based on backoff number control is provided to set backoff numbers included in a multiple polling message by registering IDs and polling periods of stations, and to countdown the backoff numbers, then to transmit data when the backoff numbers are '0', thereby preventing collision between the stations. CONSTITUTION: A data communication system receives a multiple polling message including backoff numbers assigned in each station from an access point. The data communication system sets backoff number values of the multiple polling message to backoff numbers of the stations. The data communication system countdowns the set backoff number values, and transmits data. The stations wanting to transmit the data register IDs and polling periods in the access point. The multiple polling message includes at least one of the number of stations to be polled, the IDs or backoff numbers of the stations.
Abstract:
PURPOSE: A method and device for forming a local mobility domain and a local mobility agent and an apparatus therefor are provided to set the local mobility domain and the local mobility agent according to the motion of a mobile terminal. CONSTITUTION: A router(1201) has a hop-count setup unit(12011) for receiving a hop-count and storing the received hop-count, a local mobility domain list generating unit(12012) for setting routers within a range which is less than the set hop-count value as a local mobility domain, generating a list of the routers within the local mobility domain, and storing the generated list. The router(1201) has an address management unit(12013) for receiving a region external address and a local external address from a mobile terminal(1202) and storing the region external address and the local external address in case that the address management unit(12013) is set up as a local mobility agent. The mobile terminal(1202) has a local mobility agent management unit(12021) for determining whether a connected access router is set up as the local mobility agent, receiving a list of the access router determined as the local mobility agent, and storing the received list, and an address registering unit(12022) for registering the region external address and the local external address to a home agent and the local mobility agent. The mobile terminal(1202) has a local mobility control service time adjusting unit(12023) for setting the currently connected access router as a new local mobility agent when a binding valid time is exceeded and the number of binding update messages exceeds a predetermined certain value.
Abstract:
PURPOSE: An apparatus and a method for optimizing a transmission power of a wireless personal ad-hoc network(PAN) are provided, which perform a protocol to optimize the transmission power for nodes doing multi point communication(1:N) to reduce power consumption as maintaining a communication quality. CONSTITUTION: The apparatus includes a communication part(10) including a transmission part(2) and a reception part(4), a power measuring part(20), a power control part(30), a control part(40) and a memory(50). The communication part transmits or receives data packet through air. The power measuring part measures a power of the data packet received through the reception part. The power control part controls a transmission power of the transmission part. The memory memories transmission power value as to slaves. The control part includes a link quality measuring part(32), a link quality comparison part(34) and a power control value determining part(36). The link quality measuring part measures a specific slave and a link quality on the basis of the received power of the data packet and received state parameter of the data packet. The power control value determining part determines whether to increase or decrease the transmission power to the slave according to the calculated result of the link quality comparison part.
Abstract:
PURPOSE: A method for performing local area wireless communication is provided to make a Bluetooth module start an inquiry procedure by using an HCI(Host Control Interface) command in a host, to find out an address of a peripheral Bluetooth apparatus before setting up a connection for the communication, so as to be applied to a wireless interface between a computer and a peripheral device by using Bluetooth. CONSTITUTION: A master Bluetooth module sequentially transmits preset packets for permitting data transmissions to at least more than one slave Bluetooth modules. The slave Bluetooth modules receive the preset data packets to demodulate the data packets, and supply the demodulated data packets to a host. Each of the slave Bluetooth modules receives the preset packets to modulate transmission data of the host, and supplies the modulated transmission data to the master Bluetooth module.
Abstract:
PURPOSE: A communication system is provided to transmit a data while effectively satisfy various service requirements in each terminal of high speed wireless communication system. CONSTITUTION: The system comprises an access point, at least one wireless terminal, and a media access controlling (MAC) means for controlling ATM (Asynchronous transfer mode) data transmitting operation between the access point and the wireless terminal through a wireless link which uses a wireless ATM MAC protocol. A transmitting frame used in the wireless ATM MAC protocol is formed into the order of a frame header, an up-link field for transmitting an up-link from the access point to the wireless terminal and a down-link field for transmitting a down-link from the wireless terminal to the access point. The boundary between the up-link field and the down-link field is variable. Thereby, a frame overhead of the transmitting frame is minimized by an effective bust structure, and a scheduling time of the access point is sufficiently secured.