Upload
abhi749434
View
214
Download
0
Embed Size (px)
Citation preview
7/29/2019 IJETAE_1111_03
http://slidepdf.com/reader/full/ijetae111103 1/4
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 1, Issue 1, November 2011)
20
Review of congestion control algorithms for Performance Evaluation of WCDMA
Arnika khare1, Prof. Yudhisthir Raut2
1 M.Tech Scholar, Department of Electronics And Communication, NIIST, Bhopal, M.P. India
2 Department of Electronics And Communication, NIIST, Bhopal, M.P. India
Abstract — WCDMA is an important air interface
technologies for wireless networks. As WCDMA based
cellular networks fully developed, the current point-to-
point links will evolve to an IP-based Radio Access
Network (RAN).This Paper present a review of congestion
control mechanism using Router control, channel control
and admission control method for IP-RAN on WCDMA
cellular network. The Router control mechanism uses the
features of WCDMA networks using active Queue
Management technique to reduce delay and to minimize
the correlated losses. The Random Early Detection Active
Queue Management scheme (REDAQM) is to be realizedfor the router control for data transmission over the radio
network using routers as the channel. The channel control
mechanism control the congestion by dividing the access
channel into multiple layer for data accessing. Call
Admission Control (CAC) is one of the important
methods in the performance evaluation of cellular
network of Wideband CDMA. CAC handles different
classes of users and type of services. It is the most
highlighted part and deals with the resource allocation
and resource management. The aim of this paper is
improve and enhance the quality of service by generating
different congestion control algorithms for multiclass
users
Keywords — Call Admission Control (CAC), Wideband
Code Division Multiple Access (WCDMA), Radio access
network (RAN), Active queue management (AQM),
Random Early Detection Active Queue Management
(REDAQM).
I. I NTRODUCTION
Cellular wireless networks have become an
important part of the communication infrastructure. It
has been selected for implementation in both the North
American and European 3G standards. Traditionally, in
these wireless access networks, the base stations are connected to radio network controllers or base station
controllers by point-to-point links. These links, also called backhaul links, are expensive and their use
impressive an ongoing cost on the service providers. In
such networks, reliability comes at a high price: by
replication of links or controllers.
IP RAN has the following advantages:
Cost : Point-to-point links, including T1 links, are
expensive and cannot be shared. An IP network will
benefit from statistical multiplexing gains and could be
shared with other wireless and wireless applications.
Scalability and Reliability: Replacing point-to-point
links by a distributed IP network will provide alternate
paths to more than one network controller, thereby
improving reliability and scalability. For example, it is
shown in [2] that adding a selected few paths between
base stations and network controllers results in the
majority of the gains in resiliency to failures.
Data Applications: Increasingly, a large number of IP
based “data applications,” including Web browsing,
email, streaming, and packetized voice (voice over IP)
are being offered in wireless networks. Hence, wireless
access networks must support IP traffic. An IP RAN
efficiently addresses this eventuality.
7/29/2019 IJETAE_1111_03
http://slidepdf.com/reader/full/ijetae111103 2/4
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 1, Issue 1, November 2011)
21
Fig.1. Wireless Access Network with IP RAN.
While the use of an IP RAN results in the aboveadvantages, mechanisms must be designed to control IP
RAN congestion. Congestion occurs when the offered
traffic exceeds the IP RAN capacity. There are
essentially three approaches to control and avoid
congestion:
1.CALL ADMISSION CONTROL: In WCDMA cellular
network bandwidth is varying over time due to inter
and intracell interference. To overcome the scarcity of
bandwidth in WCDMA, CAC is used. It is the rule to
admit requested calls maintaining the quality of service.
CAC is basically to make a decision about whether a
user should be admitted into the system according to
the users’ quality of service requirements and the
current traffic load.
Fig.2: Flow chart for CAC algorithm
2. ROUTER CONTROL USING ACTIVE QUEUE
MANAGEMENT : Active queue management (AQM)
[4] is a form of router control that attempts to provide
congestion control by monitoring the congestion state
of a router queue and proactively dropping packets
before the buffers become full and queuing delays
become too high. Some of the AQM policies (e.g., [7])
drop packets with a certain probability to avoid bursty
loss.
Y
N
Y
N Robust
N Fragile
N
Fig.3 active queue management
3. DIVERSITY CONTROL: Diversity allows mobile
users to smoothly transition their connections from one
cell to the next without loosing connectivity or
suffering service degradations as is typical in hard-
handoff scenarios. Diversity control selectively
discards uplink voice radio frames from potentially
redundant secondary legs for some mobile users at the
base stations in such a way that the voice quality is not
noticeably degraded while reducing traffic in the IP
RAN to manage congestion. Key challenges in
diversity control are the service degradation and
restoration policies, which dictate how users are chosen
for and freed from diversity control, respectively.
New flow
Calculate avg & maxq
Non adaptive?
Minth<avg<maxth
Avg<minth
Dro tail
Drop
RED
Accept
New state
7/29/2019 IJETAE_1111_03
http://slidepdf.com/reader/full/ijetae111103 3/4
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 1, Issue 1, November 2011)
22
In this paper, the work done in [3] is analyzed and
the future work will be to implement the same analysis
but with artificial intelligence. The rest of the paper is
organized as follows. Section II is a brief on literature
reviews of the related topics. Section III describes the
future scope with the conclusion in section IV.
II. LITERATURE SURVEY
To satisfy ever-increasing demands for higher data
rates, as well as to allow more users to simultaneously
access the network, interest has peaked in what has
come to be known as wideband code division multiple
access (WCDMA). And WCDMA is packet switched
network. An important issue in packed switched
network is congestion. In this section we discuss the
survey Of various congestion control mechanism.
Several papers are published with the impact of
congestion.
Many algorithms have been proposed for the CAC
for wireless CDMA cellular networks. In fact, this topic
is among the interest of many of the researchers.
Several papers are published with the CAC algorithm
where handoff is given priority. That is certain
bandwidth is reserved for the handoff calls also known
as guard channel policy [8, 10, 11]. Researchers have
been done in this field based upon the SINR (signal to
interference and noise ratio) calculations [12], [13]. Butin these literatures, the mobility of the user has been
kept constant. And also, the channels are not assumed
to be dynamic in nature due to which there is under
utilization of the resources when the load is not so
heavy. In paper [9,14], imperfect power is assumed to
determine the SIR. in [15] assumed the imperfect
power, dynamic channel allocation and imperfect
power. In [16], used packet switched MC-CDMA
supporting multimedia applications in which handoff is
given priority developing the CAC based on real time
measurements by estimating the effective bandwidth in
the users’ cell and the neighbouring cells too for the
mobility information. The simulation achieved low new
call blocking and handoff call dropping probabilities. In
[17], the CAC algorithm is proposed which considers
not only the cell in which the call is originating but also
neighbouring cells so that the handoff call blocking
probability is reduced. Shen, Chang et all [18] proposed
intelligent call admission controller with fuzzy logic
theory to estimate the new and handoff call interference
based on the knowledge of effective bandwidth
method. They say that intelligent system such as fuzzy
logic or neural network system cope up with the traffic
uncertainty. According to their paper, the fuzzy logic
system is preferred when there is no mathematical
model of a process. Random early Detection is one of
the active queue management control mechanism
deployed at gateways [1]. The RED gateway detects
incipient congestion by computing the average queue
size (Jacobson, 1998). The gateway could notify
connections of congestions either by dropping packets
arriving at the gateway or by setting a bit in packet
headers. When the average queue size exceeds a preset
threshold, the gateway drops or marks each arriving
packet with a certain probability, where the exact
probability is a function of the average queue size.
RED gateways keep the average queue size low whileallowing occasional burst of packets in the queue.
In[19] presented the WCDMA networks, radio
network controller (RNC) is a potential bottleneck for
TCP connections - due to difference in available
bandwidth between the core network (CN) and the
radio access network (RAN). This may result in packet
data convergence protocol (PDCP) buffer overflows or
excessive delays at the RNC, as PDCP buffers are
flow-specific. In order to avoid PDCP buffer overflows,
different active queue management (AQM) methods
may be applied at the RNC. In typical cellular
networks, mobiles can be in SHO with up to six base
stations at once with one primary leg and up to fivesecondary legs. These multiple legs constitute what is
known as the mobile’s active set. Field measurements
(also corroborated by [5] and [6]) indicate that CDMA
voice users tend to operate in SHO mode almost half of
the time, with an average of about 1.5 legs per call. In
[10] diversity control exploits traffic redundancy, it can
be a very effective congestion control technique by
adapting to congestion without either increasing the
frame error rate or blocking.
III. FUTURE SCOPE
The implementation makes few assumptions for the
implementation of the two control mechanisms such asidle channel equal speed traffic balanced, burstiness
etc.These assumptions hold well during algorithm
evaluation but may deviate in its operation in real time
scenario. An effort could be made to evaluate the
performance considering these factors also. The
proposed implementation is evaluated on apart of
image and speech sample, an effort can be made to
speed up the operation of this implementation in future.
7/29/2019 IJETAE_1111_03
http://slidepdf.com/reader/full/ijetae111103 4/4
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 1, Issue 1, November 2011)
23
The algorithm can also be tried out with other
communication system such as MC-CDMA, CSCDMA
etc. The implementation can also be evaluated
considering various channel parameters for real time
evaluation .these implementation could be made to
evaluate the performance of mobile ad-hoc network.
IV. CONCLUSION
The evolution of wireless communication for multi
bit rate application has come down to integration of
different technologies for efficient transmission of data
over wireless network. In this paper, we studied the
problem of congestion control in the IP RAN of a
WCDMA wireless access network and examined three
control techniques, called admission control, diversity
control, and router control. This paper, review of
different types of call admission control algo. is done.
The aim of this research is to enhance the same
algorithm with multiclass and multiservice user this
paper realizes the two most advanced congestion
control policies namely the Channel Admission Control
and Router Control controlling in wireless network. For
the evaluation of control algorithms a wireless network
with WCDMA standard is adapted. A router interface is
described as an intermediate interface between the
source and destination to provide better services using
an IP- enabled wireless. This algorithm is designed an
incorporated with router architecture for the control of congestion at early stage. The controlled is achieved by
floating the congestion level between minimum and
maximum threshold.
References-
[1] “Nokia Launches Its IP Radio Access Network Concept IP
RAN, ”http://press.nokia.com/PR/200002/, Feb. 2002.
[2] T. Bu, M.C. Chan, and R. Ramjee, “Connectivity, Performance,
and Resiliency of IP-Based CDMA Radio Access,” Proc. IEEEInfocom ’04, 2004.
[3] K. Maney, “Future Not So Bright for Telecoms,” USA Today,
July 2002.
[4] B. Braden, D. Clark, J. Crowcroft , B. Davie, S. Deering, D.Estrin, S. Floyd, V. Jacobson, G. Minshall, C. Partridge, L.
Peterson, K. Ramakrishnan, S. Shenker, J. Wroclawski, and L.Zhang, “Recommendations on Queue Management and
Congestion Avoidance in the Internet,” Request for Comments
2309, Network Working Group, Apr. 1998.
[5] M. Wallace and R. Walton, “CDMA Radio Network
Planning,” Proc. Third Ann. Int’l Conf. Universal Personal
Comm., Sept. 1994.
[6] S.Hong and I.-T. Lu,“Soft Handoff Parameter Optimization in
Various Propagation Environments,” Proc. Vehicular Technology Conf., 2001.
[7] S. Floyd and V. Jacobson, “Random Early Detection Gatewaysfor Congestion Avoidance,” IEEE/ACM Trans. Networking,
vol. 1, no. 4, pp. 397-413, Aug. 1993.
[8] Shristop Lindemann, Marco Lohmann and Axel Thummler , , “Adaptive Call Admission Control for QoS/ Revenue
Optimization in CDMA Cellular Networks”, Kluwer AcademicPublishers, Wireless Networks 10,457-472,2004.
[9] Yuguang Fang, Yi Zhang, “Call Admission Control Schemes
and Performance Analysis in Wireless Mobile Networks”, IEEE
Transactions on vehicular technology, vol 51, no. 2 March2002.
[10] Sneha Kumar Kasera, Ramchandran Ramjee, Sandra R.Thuel
and Xin Wang, “Congestion Control Policies for IP BasedCDMA Radio Access Networks”,IEEE transaction on mobile
computing, vol 4, no 4, Jul/Aug,2005.
[11] B. Sudhir Kumar Reddy,” Call Admission and Control Schemes
for QoS provisioning in Wireless Networks”, MTech (IT), IIT-
Bombay, April 2004.
[12] Jon M Peha and Arak Sutivong,”Admissionn ControlAlgorithm for Cellular Systems”, Kluwer Academic Publishers,
Wireless Networks 7, 117-125, 2001.
[13] Derong Liu, Yi Zhang and Sanqing Hu,” Call Admission
Policies on Calculated Power Control Setpoints in SIR- BasedPower-Controlled DS-CDMA Cellular Networks”, Wireless
Networks 10,473-483, 2004.
[14] Mohamed H. Ahmed and Halim Yanikomeroglu,” SINR Threshold Lower Bound for SINR-based Call Admission
Control in CDMA Networks with Imperfect Power Control”IEEE Communications Letters, Vol 9, no. 4, April2005.
[15] Yiannis Argyropoulos, Scott Jordan and Srikant
P.R.Kumar,”Dynamic Channel Allocation in Interference-Limited Cellular Systems with Uneven Traffic Distribution”,
IEEE Transactions on Vehicular Technology, Vol 48 no.1,1999.
[16] JinFang Zhang,” An adaptive handoff priority scheme for
wireless.”
[17] Youssef Iraqi and Raouf Boutaba, “ A Novel Distributed Call
Admission Control for Wireless Mobile Multimedia
Networks”ACM,,WOWMOM 2000 .
[18] Scott Shen, Chung-Ju Chang, Ching Yao Huang and Qi Bi,“Intelligent Call Admission Control for Wideband CDMA
Cellular Systems”, IEEE Transaction on WirelessCommunications, Vol 3. No 5, Sept 2004.
[19] Lakkakorpi, J.Cuny, R.Nokia Technol. Platforms, Espoo
“Comparison of different active queue managementmechanisms for 3G radio network controllers” : IEEE wireless
communication and networking conference.
[20] Xinxing ZhaoY.,uning Dong Hai-tao Zhao Zhang Hui JiazhouLi Can Sheng Coll. of Comm. & Inf. Eng., Nanjing Univ. of
Posts & Telecommunication., Nanjing, China “A real-time
congestion control mechanism for multimedia transmission over
3G wireless networks” January 2011.