356 results about "Congestion window" patented technology

Disclosed is a system for minimizing the effects of faults over an air link of a wireless transmission channel utilizing Transport Control Protocol (TCP). The system includes a TCP-Aware Agent Sublayer (TAS) in a protocol stack, which has a mechanism for caching both TCP packets during forward transmission and acknowledgment (ACK) return packets. The caching mechanism is located near a wireless link of the wireless transmission channel. The system also includes a link monitoring agent coupled to the TAS. The link monitoring agent monitors the condition of the wireless transmission channel for an occurrence of a predefined fault. Once a predefined fault is detected, a system response is implemented based on the type of fault encountered. When the fault is an air link packet loss, an associated packet is immediately retransmitted from the cache, and when the fault is a temporary disconnect, a congestion window of the TCP source is closed.

A communication terminal (1) on a transmission side comprises means (1-10) for detecting congestion, means (1-7) for detecting a sign of congestion with reference to an ideal congestion window size and a current congestion window size, means for estimating a ratio of priority traffic with respect to traffic within a network, and means (1-6) for dynamically changing a threshold value for detection of the sign of congestion in response to the estimated ratio. When the congestion or the sign of congestion is detected, a congestion window size is changed into the idea congestion window size.

An Explicit Congestion Notification (ECN) method is disclosed for wireless applications to avoid network congestion in a TCP/IP packet-switched network. Such method comprises transmitting, at a source node, data packets to a destination node, via at least an intermediate node; determining, at the intermediate node, if an incipient congestion is encountered, setting a Congestion Experienced (CE) flag in each data packet to notify congestion; sending, at the destination node, an ECN-Echo acknowledgment packet back to the source node to inform congestion; reducing, at the source node, a congestion window and a transmission rate to avoid congestion; if the packet loss is due to congestion, re-transmitting, at the source node, only a lost packet to the destination node; alternatively, if the packet loss is due to transmission error, re-transmitting, the lost packet to the destination node, while increasing a round-trip timeout but maintaining the same congestion window.

Improved data transport and management within a network communication system may be achieved by utilizing a transmit timer incorporated within the sender device and exploiting host-level statistics for a plurality of connections between a sender and receiver. The period of the transmit timer may be periodically adjusted based on a ratio of the smoothed round-trip time and the smoothed congestion window, thereby reducing or eliminating bursty data transmission commonly associated with conventional TCP architectures. For applications having a plurality of connections between a sender and a receiver that share a common channel, such as web applications, the congestion window and smoothed round trip time estimates for all active connections may be used to initialize new connections and allocate bandwidth among existing connections. This aspect of the present invention may reduce the destructive interference that may occur as different connections compete with one another to maximize the bandwidth of each connection without regard to other connections serving the same application. Error recovery may also be improved by incorporating a short timer and a long timer that are configured to reduce the size of the congestion window and the corresponding transmission rate in response to a second packet loss with a predefined time period in order to increase resilience to random packet loss.

Via real time online bandwidth measurement, this method confirms the threshold value ssthresh. When the congestion window (CW) is less than a half of the threshold, the rule of exponent gain is followed. Otherwise CW gains each time a value of a half of difference of the threshold and CW (ssthresh-cwnd) to approach gradually the threshold. Until the difference is less than the regulation factor phi (ssthresh/2>= phi >=2). Then CW is set as the threshold value to enter the stage of avoiding congestion. This invention can reduce the happening of loss of several texts in a window at the slowly start stage, reduce the package loss rate and raise the net transferring ability.

A packet size control method allowing reduction in the period of time during which transmission is in a blocked state is disclosed. The size of a packet to be sent is determined depending on a measured round trip time (RTT), a current bandwidth of the data link layer, and a current congestion window size. First, a maximum segment size (MSS) is obtained based on the measured RTT and the current bandwidth of the data link layer using a table obtained by data transfer simulation. Thereafter, the obtained MSS is corrected using the current congestion window size. And the correct MSS is used to determine the final segment of data to be sent.

Provided are apparatuses and methods for transmitting or receiving data packets in a data block in a communication network with a transport protocol. In one example, a loss tolerant TCP protocol is used in which a maximum segment size (MSS) may be adapted to a minimum granularity of a congestion window. Also, proactive forward error correction (FEC) packets may be added to a window of the data block. The number of proactive FEC packets may be determined, for example, based on an estimate erasure rate. In addition, reactive FEC packets may be added to the data block. Also, a receiver may receive data packets in a data block and process a selective acknowledgment (SACK) responsive to the data packets received.

A system, method, and computer program product are provided for bi-directional communication. The system includes a first host capable of transmitting multiplexed data at a first transmission rate and operating with a first congestion window. The first host is also capable of receiving multiplexed data at a second transmission rate from a second host capable of operating with a second congestion window. The first host can be capable of configuring at least one of a size of the first congestion window and a size of the second congestion window based upon first transmission rate, the size of the second congestion window, the second transmission rate and the size of the first congestion window.

Multimedia information communicated between a transmitter and a receiver may be transcoded by intercepting the multimedia information within a network communication system. The available transmission rate of the downlink channel may be estimated by, for example, calculating a ratio of the smoothed round trip time of packets communicated to the receiver and a smoothed congestion window associated with the downlink channel. If the transmission rate at which the multimedia information is encoded is greater than the available transmission rate, the multimedia information may be transcoded to conform the multimedia information to the available transmission rate. The transcoded multimedia information may then be transmitted to the receiver over the downlink channel using a transmission timer.

The invention discloses a collaborative work congestion control method in the high-speed network, the transmitter detects the RTT delay information and 1-bit prediction information from the router to determine the network congestion status and the congestion window is the self-adapted and adjustable. The method of the invention combines the load factor of the network path and number of the data packets in the buffers of all routers connected in the path to adjust the congestion window of the high-speed network which can effectively adapt to the transfer characteristic of the high-speed network to guarantee the better link utilization rate of the network, friendly TCP and fair of the streaming. These two congestion information mechanisms can be fused to avoid the mistaken determination of single congestion detection mode under certain environment and reduce the direct influences of the unilateral information error on the reliability of the method.

Provided are a method for transmitting data in a mobile ad hoc network in which the quantity of data transmitted is adjusted by adjusting the size of a congestion window when network duplicate ACK packets are received, and a network apparatus using the same. The method includes mapping sequence numbers of data packets to be transmitted to congestion window sizes during transmission of the data packets, determining whether there is a lost data packet or not, and if there is a lost data packet, retransmitting the lost data packet and adjusting a congestion window size to the congestion window size mapped to the sequence number of the lost data packet. Accordingly, a data rate throughput over a wireless ad hoc network can be increased.

A method of Transport Control Protocol (TCP) congestion control using multiple TCP AKCs in an integrated network including wireless links, the method including: receiving a packet retransmitted from a correspondent upon a mobile node having a packet loss in a received packet; calculating the number of acknowledgment messages to be transmitted by the mobile node; generating multiple acknowledgment messages according to the calculated number and transmitting the multiple acknowledgment messages to a transmitting node; and increasing a congestion window value corresponding to the multiple acknowledgment messages received by the transmitting node, and executing the TCP transmission.

The invention discloses a congestion control method and system based on deep reinforcement learning. The congestion control method includes: firstly, initializing the environment and model parametersof a network; and training a congestion control model by utilizing the collected current window, the throughput, the time delay, the data transmission rate and the like in the network, selecting the congestion control model with the minimum model loss function value and the maximum reward function value according to a training result, and deploying the model into the network to perform congestioncontrol. According to the method, the size of the congestion window is dynamically adjusted according to the current network throughput, round-trip time delay and data packet loss rate, so that the data transmission rate is controlled, the network throughput is improved, the data transmission delay and the data packet loss rate are reduced, the network congestion is reduced, and the aim of optimizing the network performance is fulfilled.

Methods and apparatus are provided to reduce data congestion and thus improve data throughput in gateways used in a wireless, wireline or a combination wireless and wireline communication system. The congestion management system optimally resizes, or not, congestion window (or buffer) sizing and threshold for the communication gateways based upon mathematical models. Application of the inventive congestion management method optimizes data recovery and throughput in communication networks, particularly those networks having lossy data links.

A first loss determination section 13 of a first communication device 10 determines that a data unit is lost if an acknowledgment response for the transmitted data unit from a second communication device 30 is not received within a predetermined time and retransmits the data unit when the determination is made. When a determination section 16 determines that a spurious timeout has occurred, a window control section 17 sets a target value for decreasing the size of a congestion window and then gradually decreases the size of the congestion window to the target value when the acknowledgment response is received. Therefore, in a case of executing a response algorithm for changing a slow start threshold and the congestion window, if a segment loss occurs subsequent to the spurious timeout, an efficient loss recovery is achieved and the throughput is improved.

The invention relates to a reliable transmission acceleration method facing networks with high error rate and long delay characteristics, belonging to a reliable end-to-end transmission method of internet. In the invention, reasons that the network loses packages are distinguished according to the following method on the basis of a FAST TCP protocol: when a sending end receives 3 repeated ACK packages, the difference value of the transmission speed of a previous RTT and the transmission speed of a present RTT can be determined, when the transmission speed of the present RTT is larger than thetransmission speed of the previous RTT, the network does not have congestion, and the reason for losing package is link error; and when the transmission speed of the present RTT is greatly smaller than the transmission speed of the previous RTT, then the network can have congestion, and the package loss can be determined to be caused by network congestion. Calculated RTT can accurately and timelyreflect the current network status through the invention, thereby the reflection sensitivity of a congestion window of the sending end to the network status can be enhanced.

A method and apparatus for congestion control for acknowledged communication over networks detects congestion based on trends of flight size and transmission rate in order to adapt a congestion window in accordance with a detection result. Such congestion detection enables, for example, distinguishing between the congestion with or without unfair competition. Moreover, the measured transmission rate or its trend can be filtered to compensate for time variations. An end node or a proxy can be used for congestion control.

Methods, apparatus and software for implementing enhanced data center congestion management for non-TCP traffic. Non-congested transmit latencies are determined for transmission of packets or Ethernet frames along paths between source and destination end-end-nodes when congestion along the paths is not present or minimal. Transmit latencies are similarly measured along the same source-destination paths during ongoing operations during which traffic congestion may vary. Based on whether a difference between the transmit latency for a packet or frame and the non-congested transmit latency for the path exceeds a threshold, the path is marked as congested or not congested. A rate at which the non-TCP packets are transmitted along the path is then managed as function of a rate at which the path is marked as congested. In one implementation, non-TCP traffic is managed by mimicking a Data Center TCP technique, under which the congestion marking status of the path is substituted as an input to a DCTP algorithm in place of the normally-used ECN-Echo flag input. The congestion window output by the DCTCP algorithm is then used to manage the rate at which non-TCP packets to be forwarded via the path are transmitted from a source end-node.

The present invention relates to an ARQ control apparatus and method. According to the present invention, a subscriber station performs initialization by communicating with a base station, and receives wireless link channel quality information; stores an SDU in an SDU buffer when the SDU is transmitted from an upper block, and establishes a connection with the base station for a corresponding service flow; receives QoS information on the service flow, ARQ information, and a CINR, and transmits them to the uplink scheduler; detects a TCP header of the SDU and stores TCP sequence number information; and performs a DSC for controlling an MAC ARQ window size with reference to the QoS information, ARQ information, CINR, and TCP congestion window size.

Systems and methods for per service differentiation for congestion avoidance through dropping packets based on service priority include receiving an ingress packet; responsive to no congestion, providing the ingress packet to a queue of one or more queues; and, responsive to congestion, during a congestion window, one of providing the ingress packet to the queue and dropping the packet based on a packet dropping capability and service priority of a service associated with the packet.

An embodiment of a system and method that uses inline measurements to probe available bandwidth for a transmission control protocol, and adaptively sets a slow-start threshold according to the available bandwidth. The method includes initializing a congestion window “cwnd,” sending cwnd packets, estimating an available bandwidth for the cwnd packets. The congestion window cwnd is set to a higher number, and the higher number of further packets is sent if the available bandwidth is greater than a first threshold level. The available bandwidth is re-estimated for the higher number of the further packets, and a soft start threshold “ssthresh” is set to the re-estimated available bandwidth. A statistical measure is calculated for the re-estimated available bandwidth, and the congestion window cwnd is set equal to ssthresh if a ratio of the statistical measure to the re-estimated available bandwidth is less than a second threshold level.