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Yue Zhang
Department of Computer Science
Inner Mongolia University
Huhhot, Inner Mongolia
$
utonomous
5
egion, China
stefyue8801256@163.com
Xiangyu Bai*
Department of Computer Science
Inner Mongolia University
Huhhot, Inner Mongolia
$
utonomous
5
egion, China
bxy@imu.edu.cn
Abstract—Delay Tolerant Network (DTN) shows some features
like link frequent interruptions, long delays, limited resources
and so on, while nodes fight each other to win the network
resources in the process of communication, which can lead to
network congestion in delay tolerant network. Therefore,
congestion control is a key issue in delay tolerant network
research. The present congestion control strategies are divided
into congestion detection, congestion avoidance, congestion
handling. In this paper, we qualitatively analyze and compare
typical congestion control strategies have been proposed, which
are based on the analysis of the basic characteristics of the delay
tolerant network. Through the analysis of the advantages and
disadvantages of each mechanism, we conducted further research
and discovery. Finally, we make a conclusion and propose
congestion control technology and the energy constraint balance
strategy.
Keywords- delay tolerant network; congestion control; energy
constraint
I. INTRODUCTION
After the interplanetary network [1] appeared, interrupt
latency communication scenarios have emerged on earth, then
sensor networks [2], mobile ad-hoc networks [3], and other
foreign media networks have also successively appeared, they
are collectively known as the limited network. The limited
network has characteristics of long latency, link frequent
interruptions, non-end connectivity, resource-constrained and
others, so the limited network and traditional network have
significant difference between performance and network
architecture. Therefore, Kevin Fall et al proposed delay tolerant
network architecture is based on the limited networks [4] in
2003. Compared with the traditional network architecture,
DTN architecture inserts a "bundle" layer [5] between the
application layer and the transport layer. Fig.1 shows the
modified five-layer Internet protocol stack that includes the
bundle layer, the bundle layer adopts the method of "store -
carry - forwards" approach to complete communication
between nodes. While the custody transfer mechanism is one of
the six classes of service (CoS) [6] in Bundle Protocol, solving
high latency, links frequently interrupted and other serious
issues in the delay tolerant network. However, since the social
attributes of the some nodes is selfishness, these selfish nodes
compete for network resources from each other so that lead to
the problems such as imbalance of network resource utilization.
Compared with the traditional networks, delay tolerant
network has long delay, network disconnection, poor quality of
service, resource-constrained and other features, so generating
the unbalanced distribution of network resources and network
traffic. These features lead to take place congestion in delay
tolerant network, which affects message delivery success rate.
The so-called congestion refers to a certain period of time, if
the demand for a kind of resources on the network exceeds the
available resources can provide part of the circumstances
which led to the deterioration of network performance.
Congestion control means by processing storage for a long
time in the contents of the DTN repeater to relieve the
communication process of the whole network, thus improve the
rate of message delivery.
Fig.1 Traditional network architecture and DTN architecture
II. CONGESTION CONTROL OVERVIEW
Handling congestion is mainly divided into two processes:
congestion detection and congestion control. Due to the biggest
difference between traditional network and delay tolerant
network is end-to-end reliability problems, so the traditional
network congestion control measures do not apply to delay
Traditional network architecture
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978-1-4799--5 /15/$31.00 ©2015 IEEE