Zhang et al. / J Zhejiang Univ SCI 2004 5(9):1087-1094 1087
On service differentiation in mobile Ad Hoc networks
ZHANG Shun-liang (张顺亮), YE Cheng-qing (叶澄清)
†
(College of Computer Science & Engineering, Zhejiang University, Hangzhou 310027, China)
†
E-mail: ycq@mail.hz.zj.cn
Received Jun. 25, 2003; revision accepted Sept. 27, 2003
Abstract: A network model is proposed to support service differentiation for mobile Ad Hoc networks by combining a
fully distributed admission control approach and the DIFS based differentiation mechanism of IEEE802.11. It can provide
different kinds of QoS (Quality of Service) for various applications. Admission controllers determine a committed band-
width based on the reserved bandwidth of flows and the source utilization of networks. Packets are marked when entering
into networks by markers according to the committed rate. By the mark in the packet header, intermediate nodes handle the
received packets in different manners to provide applications with the QoS corresponding to the pre-negotiated profile.
Extensive simulation experiments showed that the proposed mechanism can provide QoS guarantee to assured service traffic
and increase the channel utilization of networks.
Key words: Mobile Ad Hoc networks, IEEE802.11, DIFS, Service differentiation, QoS (Quality of Service)
doi:10.1631/jzus.2004.1087 Document code: A CLC number: TP393
INTRODUCTION
In the past several years, researchers have
made considerable efforts to provide QoS (Quality
of Service) to Internet, with proposals such as In-
tegrated Service (Braden et al., 1994) and Differ-
entiated Service (Blake et al., 1998). Both of these
architectures are based on sophisticated admission
control and resource reservation mechanism to
provide guarantee for absolute performance meas-
ures. At the same time, wireless networks are being
increasingly deployed to extend wired networks to
mobile users. QoS mechanisms are of particular
relevance in the case of wireless networks, where
the bandwidth is limited and the efficient use of it is
of special importance. What is more, rapidly in-
creasing multimedia applications impose require-
ments on communication parameters. Guaranteeing
them in wireless environment is greatly challenging,
especially for mobile Ad Hoc networks. They rep-
resent complex distributed systems, where mobile
nodes are interconnected without the need for any
fixed infrastructure. The dynamical network to-
pology causes the rerouting among mobile nodes,
which makes it difficult to provide real-time ap-
plications with appropriate QoS. Besides, the
characteristic of wireless Ad Hoc networks makes it
difficult to dynamically assign a central controller
to maintain connection state. Due to these reasons,
support QoS in wireless networks has been one of
the focuses of research in recent years.
RELATED WORK
Researchers had made considerable effort to
provide satisfactory levels of QoS in wireless
communication. Currently, the IEEE802.11 for
WLAN is the most widely used standard, so most of
the existing schemes for providing QoS are aimed
at IEEE802.11 wireless LANs, such as Blackburst
(Sobrinho and Krishnakumar, 1999), enhanced
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