The research presents molding and analytical study of several scheduling algorithms
types in real-time multiprocessor systems. The performance of three scheduling algorithms
have been analyzed : Earliest Deadline First Scheduling (EDF) , Least Laxi
ty First
Scheduling (LLF), and Earliest Deadline First until Zero Laxity Scheduling (EDZL). This
paper considers the scheduling of n periodic, independed, and preempted tasks with
implicit deadlines on a platform of m homogenous multiprocessor. It has compared in
terms of the load on the processor (processor's busyness) , the number of migrations, and
the number of preemptions and the number of times in which these algorithms did not
succeed in achieving the time limits for tasks where the latter is considered the most
important criterion in real time scheduling. It also considers scheduling growing task sets
of periodic tasks starting from 4 task set up to 64 task set, in order to study the effect of
increasing the number of tasks and processors also on the performance of the scheduling
algorithms. As a result of research, the strengths and weaknesses in the performance of
these three algorithms have presented. It is proposed the best type of real-time system to
apply each algorithm according to the strengths of its performance.
Long Term Evolution “LTE” is considered to be one of the most
important and latest communication technologies falling under the fourth
generation of cellular communications technology 4G. LTE supports
high-speed and large bandwidth which makes it
a great candidate to
providing the potential to improve the Quality of Service "QoS"
associated with specific types of data transfer. As a consequence,
researchers have paid their attentions to this type of networks. In fact, it
was a great challenge for researchers to achieve a good level of QoS for
all users as the LTE provides Audio and Data transmission to users at the
same time.
