1. Lecture 2: Facts of network technologies developments
Networking Trends

2. Introduction Computer networks:
A computer network is a system of interconnected computers and peripheral devices.
Communication:
Communications is about the transfer of information from a sender, across a distance, to a receiver
The older forms of communications technology, such as telephones and radios, use analog signals.
Computers communicate with digital signals.

3. Top Networking Research Topics
Security
Mobile Computing
Network-based computing
Cloud Computing
Grid Computing
Internet-of-things (IoT)
Voice-over-IP (VoIP)
Large-scale wireless networks (Sensors, RFID)
High-speed wireless

4. Mobile Computing
Mobile computing is a generic term describing one's ability to use technology while moving.
Mobile computing involves: mobile communication, mobile hardware, and mobile software.
Mobile Hardware includes mobile devices or device components.
Mobile software deals with the characteristics and requirements of mobile applications.
Communication issues in mobile computing include ad hoc and infrastructure networks as well as communication properties, protocols, data formats and the existing technologies.

5. Mobile Computing: Items
There are at least three different classes of mobile computing items:
portable computers, compacted lightweight units including a full character set keyboard and primarily intended as hosts for software that may be parameterized, as laptops, notebooks, notepads, etc.
mobile phones including a restricted key set primarily intended but not restricted to for vocal communications, as cell phones, smart phones, phonepads, etc.
wearable computers, mostly limited to functional keys and primarily intended as incorporation of software agents, as watches, wristbands, necklaces, keyless implants, etc.
The existence of these classes is expected to be long lasting, and complementary in personal usage, none replacing one the other in all features of convenience..

6. Mobile Computing: Devices and Limitations
Many types of mobile computers have been introduced since the 1990s including the:
Personal digital assistant/enterprise digital assistant
Smartphone
Tablet computer
Ultra-Mobile PC
Wearable computer
Limitations
Range & Bandwidth
Security standards
Power consumption
Transmission interferences
Potential health hazards
Human interface with device

7. Internet-based technologies and services: VoIP
Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or  other  packet-switched networks.
Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.

8. VoIP the process is reversed at the receiving end.
Internet telephony refers to communications services including: voice, fax, and voice-messaging applications-that are transported via the Internet, rather than the public switched telephone network (PSTN).
The basic steps involved in originating an Internet telephone call are:
conversion of the analog voice signal to digital format , and
compression/translation of the signal into Internet protocol(IP) packets for transmission over the Internet;
the process is reversed at the receiving end.

9. VoIP
VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codes which encode speech allowing transmission over an IP network as digital audio via an audio stream.
Codec use is varied between different implementations of VoIP
some implementations rely on narrowband and compressed speech, while others support high fidelity stereocodes

10. Cloud Computing
Cloud computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a utility (like the electricity grid) over a network (typically the Internet). Clouds can be classified as public, private or hybrid.

11. Cloud Computing
Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network.
At the foundation of cloud computing is the broader concept of converged infrastructure and shared services.
Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources.
Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users.

12. The Internet of Things
The Internet of Things (IoT) refers to the interconnection of uniquely identifiable embedded computing-like devices within the existing Internet infrastructure.

13. The Internet of things
We have passed the threshold where more things are connected to the Internet than people.
The transition to IPv6 also supports seemingly limitless connectivity.
Cisco IBSG predicts the number of Internet-connected things will reach 50 billion by 2020, which equates to more than six devices for every person on Earth.
Many of us in the developed world already have three or more full-time devices connected to the Internet when factoring in PCs, smartphones, tablets, television devices and the like.

14. The Internet of Things
Things, in the IoT, can refer to a wide variety of devices such as heart monitoring implants, biochip transponders on farm animals, automobiles with built-in sensors, or field operation devices that assist fire-fighters in search and rescue.
Future IoT? IoT of sensor networks, using low-power sensors that "collect, transmit, analyze and distribute data on a massive scale," says Evans.

15. The Internet of Things
Typically, IoT is expected to offer advanced connectivity of devices, systems, and services that goes beyond machine-to-machine communications (M2M) and covers a variety of protocols, domains, and applications.
IoT Applications :
Environmental Monitoring, Infrastructure Management, Industrial Applications, Energy Management, Medical and Healthcare Systems, Building and Home Automation, Transport Systems, Large Scale Deployments
IoT Trends:
Intelligence, Architecture, Complex system

16. Wireless Sensor Networks (WSNs)
A sensor network is a wireless network that consists of thousands of very small nodes called sensors.
Base station
- (WSN) stands for wireless sensor network.
- This technology involves deploying a large #number of inexpensive/small sensor nodes over the area of interest
- The main function of sensor nodes is to monitor, record, and notify a specific condition to the BS
- The collected data is transferred to the BS in multi-hop fashion from one node to another using broadcast communication.
Figure 1: Architecture of wireless sensor networks

17. Wireless Sensor Networks (cont.)
WSN Sensors are equipped with sensing, limited computation, and wireless communication capabilities.
Sensors are mainly equipped with:
A sensing unit: to sense the environmental parameters
A microcontroller to perform the local data processing
A wireless communication unit that allows node to communicate with other nodes, and
A Power Unit or a battery: that empowers all components of the sensor node.
Typical hardware components of a sensor node in wireless sensor networks

18. WSNs Applications
These pictures show some of the possible applications of WSNs.
The earliest applications of WSNs were in military field for (surveillance and control).
Later, they’re used for several civilian applications such as:
habitat monitoring
Forest fire detection and air pollution
Underground, seismological, and Volcano Monitoring
Body sensor networks and Several medical applications
they can also be integrated into many smart systems such as “smart cities”: For structural health monitoring, traffic detection, and many other
WSNs Applications

19. WSNs Challenges Limited Sensor Resources Networking Challenges
Battery power, computation capability, memory, etc.
Networking Challenges
Limited bandwidth, routing, multi-hop communication, mobility, topology control, large no. of sensors, frequent node on/off, etc.
Environment/Application-Driven Challenges
Requirements, extreme conditions, interference, etc.
Other Challenges
Security, synchronization, localization, deployment..
There are many challenges related to this class of networks, such as
limited resources of sensor nodes
networking challenges
how to perform routing and multihop communication with limited bandwidth, Topology changes, large no. of sensors
- environmental challenges and application requirements
As well as other networking challenges