Embedded system book

1. WOLAITA SODO UNIVERSITY
SCHOOL OF INFROMATICS
DEPARTEMENT OF COMPUTER SCIENCE
ASSIGNMENT OF REAL TIME AND
EMBEDDED SYSTEM

2. GROUP MEMBERS NAME
• STUDENT NAME ID NUMBER
1. ZERIHUN BORSAMO-----------------------190
2. ZINABU ZEWUDNEH------------------------191
3. ZUFANU KALEB-------------------------------193
4. YISIMA YISHAK--------------------------------186
5. TESFAHUN ABANCHE-----------------------165
6. PHAWULOS GETACHEWU------------------135
7. SOLOMON MIRTAKA------------------------147

3. CHAPTER 5
REAL TIME COMMUNICATION

4. Chapter outline
• 5.1 Basic concept and examples of real time
communication
• 5.2 Real time communication in LAN
• 5.3 Bounded access protocol
• 5.4 Real time communication over internet
• 5.5 internet of things(IOT)
• 5.6 Sensor and actuators
• 5.7 Resource reservation
• 5.8 Traffic shaping and policing
• 5.9 Scheduling mechanisms QOS MODELS

5. 5.1 Basic concept and examples of
real time communication
• Real-time communication applications are
commonly classified as either soft or hard
real-time.
• Real-time communication (RTC) is the ability
to communicate and exchange information in
real-time over the internet.
• Soft real-time applications can tolerate some
amount of lost messages, while hard real-time
applications have zero loss tolerance.

6. Examples of real time communication
# Some well-known examples of RTC
include:
• internet relay chat
• mobile devices
• the internet
• video conferencing
• instant messaging services

7. Goals for Real-time Communication
Techniques
• All methods of real-time communication aim to provide
real-time message delivery with either low
• The following are some desirable properties for real-time
communication:
• - low jitter
• - low latency
• ability to easily integrate non-real-time and real-time
services
• adaptable to dynamically changing network and track
conditions
• good performance for large networks and large numbers
of connections

8. RT Communication-System Needs
• The features of real-time system are as follows −
• Reliability
• Manageability
• Performance Predictability
# A real-time communication system (RTCS) is the
backbone of distributed control applications. To
support the timely completion of distributed real-
time activities, RTCS must ensure bounded delivery
delay for real-time messages.

9. Goals for Real-time Communication
Techniques
• The goals for the real-time communication techniques are as
follows −
• Low latency
• Ability to easily integrate non-real-time and real-time services
• Adaptable to dynamically changing network and traffic conditions
• Good performance for large networks and large numbers of
connections
• Modest buffer requirements within the network.
• High effective bandwidth utilization.
• Low overhead in header bits per packet or cell.
• Low processing overheads per packet within the network at the end
system.

10. 5.2 Real-time communication in
LAN
• Real-time communication in LAN refers to the ability to
exchange information and messages in real-time within
a local area network.
• LANs are designed to:
- provide optimized flexibility
- streamlined communication
- reduced costs.
• LANs enable devices to connect, transmit and receive
information between them, allowing users to access
shared resources and communicate with each other.

11. Examples of RTC in LANs
# Examples of real-time communication
technologies in LANs include:
• internet relay chat
• mobile devices
• video conferencing
• instant messaging services.

12. 5.3 Bounded access protocol
• Bounded Access Protocol is a type of Multiple Access Protocol used
for real-time communication (RTC) in local area networks (LANs).
• It is based on the Time-Bounded Medium Access Control (TBMAC)
protocol, which is a time-division multiple access protocol with
dynamic but predictable slot allocation.
• TBMAC is designed to provide Quality of Service (QoS) support for
real-time and multimedia communication.
• Unlike Random Access Protocols, Bounded Access Protocol provides
predictable access to the channel and avoids collisions and crosstalk
by assigning time slots to each station.
• Bounded Access Protocol is an essential feature of tools like Blitzz,
which provides easy-to-use RTC for collaborative issue resolution
and personalization.

13. 5.4 Real-time communication over
Internet
• Real-time communication, also known as RTC, refers to
the ability to exchange information and messages in
real-time over the internet.
• Some examples of real-time communication over the
internet include:
- video conferencing,
- instant messaging services
- VoIP (Voice over Internet Protocol).
# RTC has become an essential part of modern society,
enabling people to communicate and exchange critical
information instantly.

14. 5.5 Internet of things (IoT)
• The Internet of Things (IoT) refers to the
evolutionary stage of the internet, which makes a
global communicating infrastructure between
humans and machines.
• IoT is constructing the global infrastructure which
will change the fundamental aspects of our lives,
from health services to manufacturing, from
agriculture to mining.
• IoT offers a lot of benefits, including
• Locating and tracing abilities: Customers should
be capable of tracking the nodes and locating them
in a short amount of time.

15. IoT offers a lot of benefits,
• Ubiquitous information swap:
• Enhanced power solution:
• Data and intelligence management:
• Scalability:

16. IoT drawbacks IoT
• Security
• Privacy
• Flexibility
• Compliance
• Complexity
#Challenges:
Unexpected activities
Device longevity
Lack of transparency
No warnings

17. 5.6 Sensors and Actuators
• SENSORS
• A device which provides a usable output in response to a
specified measure.
• Sensor is a device that detects and responds to some type
of input from the physical environment
• Human beings are equipped with 5 different types of
sensors.
• Eyes detect light energy, ears detect acoustic energy, a
tongue and a nose detect certain chemicals, and skin
detects pressures and temperatures.
• The eyes, ears, tongue, nose, and skin receive these signals
then send messages to the brain which outputs a response.

18. Characteristics of sensors
• 1. Range
• 2. Resolution
• 3. Sensitivity
• 4. Error
• 5. Accuracy
• 6. Precision
• 7. Repeatability
• 8. Impedance
• 9. Response time
• 10. Linearity

19. Actuators.
• Definition, types and selection of Actuators; linear;
rotary; Logical and Continuous
• Actuators, Pneumatic actuator- Electro-Pneumatic
actuator; cylinder, rotary actuators,
• Mechanical actuating system: Hydraulic actuator -
Control valves; Construction,
• In a more general way, "actuator" is named as an
output transducer that initiate some action (S.
Middelhoek, Silicon Sensors, 1989)
• Actuators can be characterized as out-of-plane (bulk
micromachining) and in-plane (surface
micromachining) motion

20. 5.7 Resource reservation
• WHAT IS RSVP?
• RSVP is the means by which applications
communicate their requirements to the
network in an efficient and robust manner.
RSVP does not provide any network service;
• RSVP is developed to support traffic requiring
a guaranteed quality of service over both IP
unicast and multicast.

21. 5.8 Traffic shaping and policing
• Traffic shaping is a technique used to control
the rate of data transmission in a network to
avoid congestion and ensure real-time
performance.
• Traffic policing is another technique used to
limit the rate of traffic flow to a certain level to
prevent traffic bursts.
• In the development of automotive embedded
systems, traffic shaping is used for real-time
flows to prevent traffic bursts.

22. 5.9 Scheduling mechanism-QoS
models
What is scheduling in QoS?
• Scheduling is the process of mapping a packet to an
internal forwarding queue based on its QoS
information and servicing the queues according to a
queuing method.
Mechanisms of QoS:
• The main mechanisms are:
- resource reservation signaling
- admission control.
# The lowest service level that a network can provide is
best effort service, which does not provide QoS support.