The Quality of Service (QoS) term is refer to capability of network to prioritization and service distinguish for providing
better service to some service classes and call types.
Because of the lack of resources, from one side, and user's mobility
from the other, provision of QoS guarantees is considered at the head of the challenges that wireless cellular mobile network systems face.
Call Admission Control (CAC) is used for providing and achieving QoS guarantees in wireless systems.
This paper proposes a new CAC algorithm with priority index for providing and achieving QoS guarantees on the call level in
wireless systems in terms of new call blocking probabilities using multiple thresholds to determinate the number of acceptable new calls of each type of service.
Results of simulation provided in this paper show that the application of proposed new CAC algorithm with priority index on
the New Call Bounding Scheme (NCBS) provides a new CAC scheme which has better performance in terms of new call blocking
Probabilities and guarantees any desired level of QoS for new call types with the keeping priority of handoff calls.
Providing a good Quality of Service (QoS) for all users is a big challenge in Cellular Networks, as soon as the number of users increases the demand on Internet service increases too especially with using the current technology of today. While on mov
e a user needs Internet connectivity with good Quality of Service and minimum call dropping probability.
Cellular IP presents a good solution mobility as it supports highly mobile users, users' needs are becoming larger and more multifarious (files downloading, video streaming, sending an e-mail….) there for the need for efficient way to improve QoS is necessity.
Bandwidth is the most important factor in Cellular IP Networks, for improving QoS in Cellular IP Networks a model for bandwidth management is presented in this paper, the model presented here is based on borrowing bandwidth reserved to non-real-time users using Particle Swarm Optimization (PSO) the proposed model preserves a low bandwidth threshold for the ongoing non-real-time calls. This threshold is the security limit that keeps non-real-time calls from being dropped. This research models handoff process and proposes a technique that gives the lowest percentage of dropped and blocked hand offs. Simulation results show the efficacy of the proposed model.
Advanced Reservation (AR) is used to guarantee resource provisioning for many different types of
applications including workflows. This technique is still under a huge controversy in both Business and
Research communities because of its potentialit
y of reducing resource utilization. Most of the works
proposed in this domain suggest reservation for the whole workflow schedule, and on all available
resources at the same time, which worsen the problem of resource utilization.
Many solutions are introduced to improve resource utilization under advanced reservation through
generating relaxed and elastic reservation plans that local scheduling systems could modify to improve
utilization and decrease internal fragmentation. These solutions depend mainly on changing rigid AR,
which considered to be the most difficult kind of reservation, into relaxed and elastic ones through adding
extra time on the resulted schedule and then distributing it on all tasks of the workflow.
This paper presents a new autonomic algorithm (EWARP) for producing elastic reservation plans for
workflow applications which doesn’t add extra times. Instead, it depends on exploiting the timing gaps
produced by the different scheduling algorithms. The new algorithm use the technique of discovering
timing gaps, but modifies it, and adds to it to be used for producing an elastic reservation plan for
workflows. The results presented in this paper demonstrate how the proposed algorithm outperforms
existing works in the fields by a lower bound approximating 25%.This shows that (EWARP) algorithm
offer efficient and practical solutions for the problem of scheduling workflow applications under QoS
constrains.
Real-time multimedia transport over MANET has stringent bandwidth, delay, and loss requirements. It is
a great challenge to support such applications in wireless ad hoc networks, which are characterized by
frequent link failures, congestion, and lack of central administration.
Voice over IP Protocol is an important Internet voice connection, characterized by high
quality of service. In this work, we will assess how today's Internet service matches its
expectations by examining the performance of the Voice over IP protoco
l and its quality of
service. We have relied on the method of selection of encoders first within some
parameters to obtain the simulation result of the comparison and analysis (QoS). Which we
adopted on VoIP protocols in the case of multiple users with three algorithms for the
symbols, and after determining the problem in this range, we took a number of factors into
account due to their impact on sound performance, such as jitter and Delay. This action
simulates three of the most common encoders (analog audio conversion and packet
compression), G.711, G.723.1 and G.729. The main objective is to achieve high-quality
sound performance by making the appropriate decision in the choice of sound encoder.
