A system and method for reducing content acquisition delay of NDN network mobile users

Abstract

The invention relates to a system and method for reducing the delay in acquiring content of mobile users in an NDN network. The system includes an NDN network composed of NDN nodes, and a wireless network including a mobile node and an access point AP; the mobile node is responsible for sending an Interest packet and receiving a corresponding Data packet; the NDN node includes a prediction module and a redirection module; when When the mobile node wants to switch to another AP, the redirection module redirects the Interest packet to the NDN node corresponding to the AP predicted by the prediction module, and the corresponding NDN node provides the nearest service for the mobile node to be connected through the cached Data content . The present invention can greatly reduce the communication delay, and its feature of predicting a neighbor node one hop away is suitable for the scene of the correct next access point discarded due to excessive cache overhead, and its feature of predicting multiple hops is suitable for Scenarios where mobile nodes move and switch at high speed.

Description

technical field [0001] The patent application of the present invention belongs to the field of computer network, and specifically relates to a system and method for improving the performance of mobile users in obtaining content in a named data network (hereinafter referred to as NDN network). Background technique [0002] With the rapid development of mobile technology, the massive increase in the number of mobile devices and their mobile characteristics have degraded the performance and service quality of traditional Internet networks, and also greatly reduced the quality of service experience of mobile users. Especially when a mobile user switches between different access points, repeatedly requesting the same content not only wastes network bandwidth, but also greatly reduces the time interval from sending a request to receiving data content (hereinafter referred to as communication delay). [0003] In recent years, a variety of solutions have been proposed to address the...

AI Technical Summary

Problems solved by technology

This problem will be more serious when the mobile node switches frequently

(2) Difficult to achieve seamless switching

Mobile IP only describes the method of handover, and does not give in-depth consideration to how to reduce handover delay and packet loss rate.

(3) The cost of the care-of address registered by the mobile node is relatively large

The main disadvantages of this scheme are as follows: (1) increases the message size

Before sending the data packet, the LISP header carrying the RLOC is added to the message, which undoubtedly increases the size of the message and also occupies part of the network bandwidth during network transmission.

(2) Increased delay and packet loss rate

The disadvantages of this scheme are: (1) a large amount of control information is introduced

A large amount of control information will occupy network bandwidth during network transmission and increase the burden on the network

(2) A large amount of control information interaction will also increase the communication delay

The disadvantages of this method are: (1) In the model established for finding the next access point, factors such as the moving speed and moving direction of the mobile node are not considered, but simply assume that the current access point AP i All neighbor nodes of are equally likely to be the next access point, so the analysis of the mobility factor is missing

(2) During the experiment, we only estimate different delay overhead ratios and cache overhead ratios, and set different fixed values ​​for experiments, so the experimental results lack reliability

(3) In actual scenarios such as schools and shopping malls in hotspot areas, after a period of time, these access points have a large cache overhead. Assume that an access point in a hotspot area is always discarded by the target cost function because of the cache overhead. That is, it is not included in S*, but the next access point of the mobile user is often this abandoned access point, so this method not only wastes the cache overhead of other neighbor access points, but also has to go to the content provider The delay overhead caused by acquiring content is always the largest, so this method is invalid in this scenario

(4) In the scenario where the mobile user moves at high speed and switches between different networks, the link duration between the mobile user and the neighbor access point is not long enough for the neighbor access point to cache the required content. If the cache wastes the cache of the neighbor node, It also does not meet the needs of mobile seamless handover, so this method is also invalid in this scenario

This solution only directly maps the mobile solution in the traditional network to the NDN network, and does not make full use of the advantages brought by the NDN network architecture

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