25-08-2017, 09:32 PM
A Modern Approach for Improving Quality of Service in 4G Wireless Networks
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Abstract
The aim of this paper is to enhance the Quality of
Service (QoS) in 4Gwireless networks. The various QoS factors in
wireless communications are Bit Error Rate, access delay,
Throughput and network life time. A new QoS factor namely User
Satisfaction Factor (USF) has been proposed which is a function of
both the number of received bits and the delay sensitivity. This USF
not only predicts the final delivered QoS, but also takes advantages of
the fact that different packets can be decoded at different time in the
receivers. Based on this USF, three types of scheduling schemes are
considered such as the maximum approach, the overall performance
approach, and the proportional approach. These scheduling schemes
achieve different tradeoffs between system performance and
individual fairness.
INTRODUCTION
OURTH-GENERATION (4G) is a term used to describe
the next complete evolution in wireless communications.
A 4G system will be able to provide a comprehensive IP
solution where voice, data and streamed multimedia can be
given to users on an "Anytime, Anywhere" basis, and at higher
data rates than previous generations. The fourth generation is
the total replacement of the current 3G networks. The
objectives of 4G include: that 4G will be a fully IP-based
integrated system. 4G will be capable of providing between
100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors,
with premium quality and high security. The infrastructure and
the terminals of 4G will have almost all the standards from 2G
to 4G implemented. Although legacy systems are in place to
adopt existing users, the infrastructure for 4G will be only
packet-based (all-IP). Some proposals suggest having an open
platform where the new innovations and evolutions can fit.
The technologies which are being considered as pre-4G are the
following: Flash-OFDM, WiMax, WiBro, iBurst, 3GPP Long
Term Evolution and 3GPP2 Ultra Mobile Broadband.
ADMISSION CONTROL IN THE CONTEXT OF FUTURE
HETERO –GENEOUS WIRELESS SYSTEMS
In order to ensure a high degree of satisfaction of user QoS
requirements, a form of cooperation between WINNER and
legacy RANs is required. A universal admission control
mechanism across all networks that operate in the same area is
a key element in achieving their efficient cooperation. The
main goal of the AC algorithm is to control the admission of
new or handover sessions while maintaining the load of the
network within some boundaries that do not disturb the QoS
of any other sessions. The main function of an efficient AC
algorithm for heterogeneous networks is to decide at a specific
point in time if there is a network that has the available
resources to serve (to satisfy the QoS requirements of) a new
session [6]. The design of the AC algorithm must be made
very carefully to minimize the following: False rejections,
false admissions.
CONCLUSION
In this paper, we define a new QoS measurement for
Multimedia and data transmissions considering heterogeneous
and delay sensitive applications. Based on this measurement,
four scheduling schemes are proposed. From the simulation
results, compared with the weighted round-robin and modified
proportional fair schemes, the proposed schemes find the
different tradeoffs between individual fairness and system
Performance, while the heterogeneous nature and delay
sensitivity of payloads are considered. The schemes can be
further generalized to facilitate the design of the future
wireless networks.