Introduction to IoT
Module 1:
I. Basics of Networking: Today’s world relies heavily on data and networking, which allows for
the instant availability of information from anywhere on the earth at any moment. Networking refers
to the linking of computers and communication network devices (also referred to as hosts), which
interconnect through a network (Internet or Intranet) and are separated by unique device identifiers
(Internet protocol, IP addresses and media access control, MAC addresses). These hosts may be
connected by a single path or through multiple paths for sending and receiving data. The data
transferred between the hosts may be text, images, or videos, which are typically in the form of binary
bit streams.
Network Types: Computer networks are classified according to various parameters:
1)Type of connection
2) physical topology, and
3) reach of the network.
These classifications are helpful in deciding the requirements of a network setup and provide insights
into the appropriate selection of a network type for the setup.
1. Connection type (Type of connection):
Depending on the way a host communicates with other hosts, computer networks are
of two type:
Point-to-point
Point-to-multipoint.
1.1 Point-to-point:
Point-to-point connections are used to establish direct
connections between two hosts. Day-to-day systems such as
a remote control for an air conditioner or television is a point
to point connection, where the connection has the whole
channel dedicated to it only. These networks were designed
to work over duplex links and are functional for both
,synchronous as well as asynchronous systems. In computer networks, point to point connections find
usage for specific purposes such as in optical networks.
1.2 Point-to-multipoint
In a point-to-multipoint connection, more than two hosts share the same link. This type of
configuration is similar to the one-to-many connection type. Point-to-multipoint connections find
popular use in wireless networks and IP telephony.
The channel is shared between the various hosts, either spatially or temporally. One common
scheme of spatial sharing of the channel is frequency division multiple access (FDMA). Temporal
sharing of channels includes approaches such as time division multiple access (TDMA). Each of the
spectral and temporal sharing approaches has various schemes and protocols for channel sharing
in point-to-multipoint networks. Point-to multipoint connections find popular use in present-day
networks, especially while enabling communication between a massive number of connected
devices.
2.Physical topology
Depending on the physical manner in which communication paths between the hosts are
connected, computer networks can have the following four broad topologies like
Star
Mesh
Bus
Ring
, 2.1 Star connection: In a star topology, every host has a point-to-point link to a central controller or
hub. The hosts cannot communicate with one another directly; they can only do so through the central
hub. The hub acts as the network traffic exchange. For large-scale systems, the hub, essentially, has
to be a powerful server to handle all the simultaneous traffic flowing through it. However, as there
are fewer links (only one link per host), this topology is cheaper and easier to set up. The main
advantages of the star topology are easy installation and the ease of fault identification within the
network. If the central hub remains uncompromised, link failures between a host and the hub do not
have a big effect on the network, except for the host that is affected. However, the main disadvantage
of this topology is the danger of a single point of failure. If the hub fails, the whole network fails.
Fig1 Star connection Fig2.Mesh Topology
2.2 Mesh Topology: In a mesh topology, every host is connected to every other host using a
dedicated link (in a point-to-point manner). This implies that for n hosts in a mesh, there are a total
of n(n-1)/2 dedicated full duplex links between the hosts. This massive number of links makes the
mesh topology expensive. However, it offers certain specific advantages over other topologies. The
first significant advantage is the robustness and resilience of the system. Even if a link is down or
broken, the network is still fully functional as there remain other pathways for the traffic to flow
through. The second advantage is the security and privacy of the traffic as the data is only seen by the
intended recipients and not by all members of the network. The third advantage is the reduced data
load on a network. The reduced data load on a single host, as every host in this network takes care of
its traffic load.
Module 1:
I. Basics of Networking: Today’s world relies heavily on data and networking, which allows for
the instant availability of information from anywhere on the earth at any moment. Networking refers
to the linking of computers and communication network devices (also referred to as hosts), which
interconnect through a network (Internet or Intranet) and are separated by unique device identifiers
(Internet protocol, IP addresses and media access control, MAC addresses). These hosts may be
connected by a single path or through multiple paths for sending and receiving data. The data
transferred between the hosts may be text, images, or videos, which are typically in the form of binary
bit streams.
Network Types: Computer networks are classified according to various parameters:
1)Type of connection
2) physical topology, and
3) reach of the network.
These classifications are helpful in deciding the requirements of a network setup and provide insights
into the appropriate selection of a network type for the setup.
1. Connection type (Type of connection):
Depending on the way a host communicates with other hosts, computer networks are
of two type:
Point-to-point
Point-to-multipoint.
1.1 Point-to-point:
Point-to-point connections are used to establish direct
connections between two hosts. Day-to-day systems such as
a remote control for an air conditioner or television is a point
to point connection, where the connection has the whole
channel dedicated to it only. These networks were designed
to work over duplex links and are functional for both
,synchronous as well as asynchronous systems. In computer networks, point to point connections find
usage for specific purposes such as in optical networks.
1.2 Point-to-multipoint
In a point-to-multipoint connection, more than two hosts share the same link. This type of
configuration is similar to the one-to-many connection type. Point-to-multipoint connections find
popular use in wireless networks and IP telephony.
The channel is shared between the various hosts, either spatially or temporally. One common
scheme of spatial sharing of the channel is frequency division multiple access (FDMA). Temporal
sharing of channels includes approaches such as time division multiple access (TDMA). Each of the
spectral and temporal sharing approaches has various schemes and protocols for channel sharing
in point-to-multipoint networks. Point-to multipoint connections find popular use in present-day
networks, especially while enabling communication between a massive number of connected
devices.
2.Physical topology
Depending on the physical manner in which communication paths between the hosts are
connected, computer networks can have the following four broad topologies like
Star
Mesh
Bus
Ring
, 2.1 Star connection: In a star topology, every host has a point-to-point link to a central controller or
hub. The hosts cannot communicate with one another directly; they can only do so through the central
hub. The hub acts as the network traffic exchange. For large-scale systems, the hub, essentially, has
to be a powerful server to handle all the simultaneous traffic flowing through it. However, as there
are fewer links (only one link per host), this topology is cheaper and easier to set up. The main
advantages of the star topology are easy installation and the ease of fault identification within the
network. If the central hub remains uncompromised, link failures between a host and the hub do not
have a big effect on the network, except for the host that is affected. However, the main disadvantage
of this topology is the danger of a single point of failure. If the hub fails, the whole network fails.
Fig1 Star connection Fig2.Mesh Topology
2.2 Mesh Topology: In a mesh topology, every host is connected to every other host using a
dedicated link (in a point-to-point manner). This implies that for n hosts in a mesh, there are a total
of n(n-1)/2 dedicated full duplex links between the hosts. This massive number of links makes the
mesh topology expensive. However, it offers certain specific advantages over other topologies. The
first significant advantage is the robustness and resilience of the system. Even if a link is down or
broken, the network is still fully functional as there remain other pathways for the traffic to flow
through. The second advantage is the security and privacy of the traffic as the data is only seen by the
intended recipients and not by all members of the network. The third advantage is the reduced data
load on a network. The reduced data load on a single host, as every host in this network takes care of
its traffic load.
