Pervasive service-oriented adaptive network congestion control method

Abstract

The invention relates to a pervasive service-oriented adaptive network congestion control method. The method comprises the following steps that: a source node for transmitting information measures round-trip time (RTT) of a target node for receiving the information, wherein when the ratio CSRTT of the latest measuring value to the minimum of the historical RTT is increased, the congestion is caused by too many packets forming a line in an intermediate network node; the target node distinguishes the received data packet is a normal data packet or is a packet-pair used for detecting bandwidth and feeds the estimated available bandwidth back to the source node; according to a feedback signal, the source node distinguishes the congestion states with four levels according to a preset rule and uses the four congestion states as a basis of speed adjustment; when a new connection exists, the target node transmits three repeated acknowledge characters (ACK) of the last received data before switching; and the source node resets a slow start threshold by using the result after receiving an acknowledgment packet which is not data bursting one window, but data for only transmitting two back-to-back packets to detect the available bandwidth on a new path.

Description

【Technical field】 [0001] The invention belongs to the technical field of combining computer application and mobile Internet. 【Background technique】 [0002] With the development of computing technology, a variety of new computing devices are widely used in computer networks and penetrate into all aspects of social life. Under this background, human beings have entered the era of ubiquitous computing. It envisions a world in which computers, handheld devices, sensors, and other physical devices such as home appliances are seamlessly combined to provide ubiquitous services. This service model is called pervasive service. The main characteristics of ubiquitous services are the diversity and autonomy of devices in the environment and the variability and context relevance of the environment itself. [0003] The network environment of pervasive service is a mixed network environment composed of broadband network, narrowband network and wireless network. This extremely complex h...

AI Technical Summary

Problems solved by technology

Although increasing storage space can alleviate this problem to a certain extent, studies have shown that excessively large caches can lead to worsening congestion

Because the data packets in the network are forwarded through the router after a long queue, it will waste network resources and aggravate network congestion.

[0010] 2. Insufficient link bandwidth capacity

The mismatch between the high-speed link and the low-speed link is generally manifested in a heterogeneous network; or the sum of multiple input bandwidths is greater than the bandwidth capacity, which will cause the data arrival rate in the router to be much greater than the sending rate, resulting in buffer capacity Limited, causing network congestion

[0011] 3. The processing power of the processor is weak and the speed is slow

However, this mechanism also has several shortcomings: First, it uses the network layer protocol to transmit feedback, and uses the transport layer protocol to reduce congestion. The coexistence of multiple protocols on these layers will result in unfair resource sharing among data streams.

Second, feedback in some strategies requires additional feedback packets in the network

[0017] The existing Freeze-TCP method is designed for wireless mobile networks. When the network is switched, no matter what environment the switch is in, after the switch is over, the sender will send data with the window size before the switch, but it is applied to heterogeneous networks. In the environment, it will cause unnecessary network congestion due to ignorance of the network status, resulting in network performance degradation

For example, assuming that the mobile device switches from the WLAN to the GPRS network, if the sender sends a window of data in the GPRS network according to the sending window size in the WLAN, it is likely that the GPRS network will be congested due to the sharp reduction of the network bandwidth, resulting in The loss of a large number of data packets affects the performance of TCP

Similarly, when the mobile device is switched from the GPRS network to the wireless LAN, although the above situation will not occur, the wireless LAN can withstand bursty data with its high bandwidth, but it will also bring another problem at the same time, because it is possible before the switch. The sending end has entered the congestion avoidance stage, and the slow window growth rate cannot obtain the available network bandwidth in a short time, resulting in a waste of a lot of network resources

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