Abstract:
A method for generating packet-based transmission control parameters includes (a) receiving class information of an audio-video (AV) application and characteristic information of an AV packet, from the AV application, (b) receiving status information of a wireless channel and buffer storage time information of the AV packet, from a medium access control (MAC) layer, and (c) generating and outputting the packet-based transmission control parameters on the basis of the received information. In addition, a selective retransmission method includes (a) transmitting packets of an MPEG-2 frame in real-time, (b) checking for any transmission error after the transmission, and (c) if any transmission error is generated, retransmitting only packets of an I-frame. Therefore, it is possible to efficiently support AV service in wireless communication by dynamically controlling transmission control parameters according to a buffer status and by reflecting the characteristics of the AV frames.
Abstract:
PURPOSE: A method and a device for controlling a receiving power consumption in a wireless LAN based on CSMA/CA(Carrier Sense Multiple Access/Collision Avoidance) are provided to turn off power of the rest components except a minimum number of components necessary for stabilizing, thereby reducing power consumed during a medium sensing operation. CONSTITUTION: An RPC(Receive Power Controller) receives a PLCP(Physical Layer Convergence Protocol) and an MAC frame(50), and extracts a transmission rate and frame transmission section information from the received information(51), then determines a power control section by interpreting the extracted information(52). The RPC compares a receiving address of the MAC frame with a self address(53). If the compared addresses are different, the RPC converts power of a baseband layer and an RF layer into a low-power state(54). When the power is off, the RPC counts the power control section(55), and converts the low-power state into a normal state(56). The RPC stabilizes an operation of the RF layer by applying the power(57).
Abstract:
PURPOSE: A method for transmitting a high-speed frame in a wireless LAN is provided to relay a frame if a transmission rate gain can be obtained through a relay node, in case a transmission rate deteriorates, thereby effectively using wireless resources. CONSTITUTION: A system requests a path search process(400), and generates a reliable node request data frame to transmit the frame to the second wireless terminal(402). A wireless AP(Access Point) checks an optimum path(410). A data relay process is carried out(420). If data is transmitted through the first wireless terminal, the wireless AP configures a data frame to be transmitted to the second wireless terminal, and sends the configured data frame to the first wireless terminal(422). A response signal is generated, so that the data is transmitted to the wireless AP(426).
Abstract:
PURPOSE: A method and apparatus for dynamically controlling a real time multimedia data generation rate are provided to be quickly adopted for a radio channel state and effectively use resources by detecting characteristics of a radio channel and reflecting the detected result for a multimedia data generation rate. CONSTITUTION: A data generator generates multimedia data according to a data generation rate and transmits it to a mobile terminal or a wireless access node(AP) through an RTP(Real Time Protocol)(310). An RTCP(Real-time Transport Control Protocol) receives information on a transmission buffer transmitting multimedia and multimedia data loss rate from an MAC(Medium Access Control) layer(320). A generation rate of the multimedia data is calculated and transmitted to the data generator(330). The data generator generates multimedia data on a real time basis according to the received multimedia data generation rate and transmits it to the RTP(340).
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.