Applications of Adhoc wireless network – ASSIGNMENT No: 1 APPLICATIONS OF ADHOC WIRELESS NETWORK – Studocu

ASSIGNMENT No: 1

APPLICATIONS OF ADHOC

WIRELESS NETWORK

SUHILA V M

MTECH IT(Software Systems)
ROLL NO:
SOE,CUSAT

INTRODUCTION

Adhoc network is an autonomous system node connected with wireless link. The
node in the ad hoc network communicates with other node without any physical
representation. The nodes in the ad hoc organization instantly form the network whenever the
communication is established. Each node in the network communicates with other node using
radio waves. The entire network is distributed and nodes are collaborated with each other
without fixed station access point (AP) or base station. An ad hoc network is local area
network that builds an automatic connection to the nodes in the network

The wireless network architecture is be classified in two ways, first one is
infrastructure where the node are connected with the fixed physical representation. Thus, the
nodes are communicated through AP (Fig. 1). Examples for these kinds of wireless networks
are GSM, UMTS and WLAN etc.

Fig 1: Infrastructure based Adhoc wireless Network

Second is infrastructureless where the node is communicated without any fixed
physical representation. The ad hoc networks are formed by connecting the terminals in the
multi-hop distributed architecture. Due to the absence of centralized structure, the nodes in
the ad hoc network acts as router to send and receive the data (Fig. 2).

Fig 2: Adhoc Wireless Network

I. MANET(MOBILE AD HOC NETWORK )

A mobile ad hoc network (MANET) is a continuously self-configuring, infrastructure-
less network of mobile devices connected without wires. Ad hoc is Latin and means “for this”
(i., for this purpose).

Each device in a MANET is free to move independently in any direction, and will
therefore change its links to other devices frequently. Each must forward traffic unrelated to
its own use, and therefore be a router. The primary challenge in building a MANET is
equipping each device to continuously maintain the information required to properly route
traffic. Such networks may operate by themselves or may be connected to the larger Internet.
They may contain one or multiple and different transceivers between nodes. This results in a
highly dynamic, autonomous topology.

MANETs are a kind of Wireless ad hoc network that usually has a routable
networking environment on top of a Link Layer ad hoc network. MANETs consist of a peer-
to-peer, self-forming, self-healing network. MANETs circa 2000-2015 typically
communicate at radio frequencies (30 MHz – 5 GHz)

The growth of laptops and 802/Wi-Fi wireless networking have made MANETs a
popular research topic since the mid-1990s. Many academic papers evaluate protocols and
their abilities, assuming varying degrees of mobility within a bounded space, usually with all
nodes within a few hops of each other. Different protocols are then evaluated based on
measures such as the packet drop rate, the overhead introduced by the routing protocol, end-
to-end packet delays, network throughput, ability to scale, etc.

I Types of MANET

There are four types of MANETs which are working in present scenerio:

1. Vehicular Ad-hoc Networks (VANETs) Vehicular Ad-hoc Networks (VANETs) play
   a greater role in the communication among the vehicles that act as mobile nodes and
   between the vehicles and roadside equipment.
2. Intelligent vehicular ad-hoc networks (InVANETs) Intelligent vehicular ad-hoc
   networks (InVANETs) are based on artificial intelligence and specially designed to
   help the vehicles moving on the road to behave in an intelligent manner during
   vehicle-to-vehicle collisions, accidents, etc. The main purpose of InVANETs is the
   road safety.
3. Internet Based Mobile Ad-hoc Networks(iMANET) The third type of MANET is
   Internet Based Mobile Ad-hoc Networks (iMANET) that connect mobile nodes and

fixed Internet-gateway nodes. In these type of networks normal ad hoc routing
algorithms don’t apply directly.
4. Smartphone Adhoc Networks(SPANs) leverage the existing hardware (primarily
Bluetooth and Wi-Fi) in commercially available smart phones to create peer-to-peer
networks without relying on cellular carrier networks, wireless access points, or
traditional network infrastructure. SPANs differ from traditional hub and
spoke networks, such as Wi-Fi Direct, in that they support multi-hop relays and there
is no notion of a group leader so peers can join and leave at will without destroying
the network.

I Characteristics of MANET

1. Self Governing Behaviour: In MANET, each node act as both host and router. When a
   source node and destination node is out of the radio range to send or receive any
   message respectively, at that time the MANETs are capable of multi-hop routing.
2. Actively changing Network Topology: The nodes can join or leave the network
   anytime, making the network topology dynamic or actively changing in nature.
3. Spontaneous Behaviour: It demands minimum human interference to configure the
   network.
4. Harmonious Environment: All nodes have indistinguishable attributes with similar
   responsibilities and capabilities and therefore it leads to complete symmetry and
   harmony in an environment.
5. Centralized Firewall Absent: Distributed nature of operation for security, routing and
   host configuration.
6. User Density and Mobility: MANETS provide High user density and large level of
   user mobility
7. Less Memory and Power Usage: Mobile require less memory, and consume less
   power and have many light weight features.
8. Inferior to Wired Links: The Stability, Reliability, Efficiency and capacity of
   wireless links are lesser than wired links so there is variation in the link bandwidth
   of wireless links.

I Applications of MANET

Following are some of the applications of Mobile Ad Hoc Networks:

 MANETs play a greater role in the Strategic networks such as automated battlefields.
It is used for Communication purposes and for performing various operations in
Military department.

and constantly changing their position within network. For example consider a
MANET (Mobile Ad-hoc Network) where node B sends a signal to node A but this
does not tell anything about the quality of the connection in the reverse direction.
2. Routing Overhead : In wireless ad hoc networks, nodes often change their location
within network. So, some out-of-date routes are generated in the routing table, which
leads to unnecessary routing
3. Overhead Interference : This is the major problem with mobile ad-hoc networks as
links come and go depending on the transmission characteristics, one transmission
might interfere with another one and node might overhear transmissions of other
nodes and can corrupt the total transmission.
4. Dynamic Topology : This is also the major problem with ad-hoc routing since the
topology is not constant. The mobile node might move or medium characteristics
might change. In ad-hoc networks routing tables must somehow reflect these changes
in topology and routing algorithms have to be adapted. For example in a fixed
network routing table updating takes place for every 30sec. This updating frequency
might be very low for ad-hoc networks.

II. VANET (VEHICULAR ADHOC NETWORKS)

VANET is an application of mobile ad hoc network. More precisely a VANET is self-
organised network that can be formed by connecting vehicle aiming to improve driving safety
and traffic management with internet access by drivers and programmers. Two types of
communication are provided in the VANET.

First a pure wireless ad hoc network where vehicle to vehicle without any support of
infrastructure. Second is communication between the road side units (RSU), a fixed
infrastructure, and vehicle. Each node in VANET is equipped with two types of unit i. On
Board Unit and Application Unit (AU). OBU has the communicational capability whereas
AU executes the program making OBU>s communicational capabilities. An RSU can be
attached to the infrastructure network which is connected to the Internet. Fig 3 describes
C2C-CC architecture of VANET.

Fig 3: C2C-CC reference architecture

To establish a VANET, IEEE has defined the standard 802 or 802 (WiMax). A
Dedicated Short Range Communication (DSRC) is proposed which is operating on 5
band and uses 802 access methods. It is standardised as 802 which provides short
range communication with low latency. USA has allocated 75MHz of spectrum in the
5 band for DSRC to be used by Intelligent Transportation Systems (ITS). Also, Europe
has allocated 30 MHz of spectrum in the 5 band for ITS.

Some protocols are being developed by the other groups also. NOW (Network on
Wheels), which is associated with Car-2-Car Consortium, has developed some protocols.
Ford and General Motors have also created a Crash Avoidance Metric Partnership (CAMP)
in order to improve the VANET services.

The ultimate goal of all works toward VANET is to provide road safety information
among the nodes hence the frequent exchange of such type of data on the network clearly
signifies the role of the security. Any successful attack can cause loss of lives or financial
lose. Hence the security of the information in VANET is crucial. In this article we are going
to discuss the security challenges and major attacks on VANET and also discuss the existing
solution for these attacks.

II VANET APPLICATIONS AND CHARACTERISTICS

To deploy VANETs, there must be some commercial applications that benefit from
them. The applications where VANET can play major role can be categorised into two broad
categories.

AE-RIS program will work in partnership with the vehicle-to-vehicle (V2V)
communications research effort to better define how connected vehicle data and
applications might contribute to mitigating some of the negative environmental
impacts of surface transportation.

 Time Utilization: If a traveler downloads his email, he can transform jam traffic into a
productive task and read on-board system and read it himself if traffic stuck. One can
browse the Internet when someone is waiting in car for a relative or friend.

 Fuel Saving : When the TOLL system application for vehicle collects toll at the toll
booths without stopping the vehicles, the fuel around 3% is saved, which is consumed
when a vehicles as an average waits normally for 2-5 minutes.

II Characteristics of VANET

VANET is an application of MANET but it has its own distinct characteristics which
can be summarised as:

 High Mobility: The nodes in VANETs usually are moving at high speed. This makes
harder to predict a node?s position and making protection of node privacy.
 Rapidly changing network topology: Due to high node mobility and random speed of
vehicles, the position of node changes frequently. As a result of this, network
topology in VANETs tends to change frequently.
 Unbounded network size: VANET can be implemented for one city, several cities or
for countries. This means that network size in VANET is geographically unbounded.
 Frequent exchange of information: The ad hoc nature of VANET motivates the nodes
to gather information from the other vehicles and road side units. Hence the
information exchange among node becomes frequent.
 Wireless Communication: VANET is designed for the wireless environment. Nodes
are connected and exchange their information via wireless. Therefore some security
measure must be considered in communication.
 Time Critical: The information in VANET must be delivered to the nodes with in time
limit so that a decision can be made by the node and perform action accordingly.

 Sufficient Energy: The VANET nodes have no issue of energy and computation
resources. This allows VANET usage of demanding techniques such as RSA, ECDSA
implementation and also provides unlimited transmission power.
 Better Physical Protection: The VANET nodes are physically better protected. Thus,
VANET nodes are more difficult to compromise physically and reduce the effect of
infrastructure attack.

II Issues in Vanet

Although the characteristics of VANET distinguishes it a different network but some
characteristics imposes some challenges to deploy the VANET. These challenges can be
categorised into following categories:

1. Technical Challenges

The technical challenges deals with the technical obstacles which should be resolved
before the deployment of VANET. Some challenges are given below:

 Network Management: Due to high mobility, the network topology and channel
condition change rapidly. Due to this, we can?t use structures like tree because these
structures can?t be set up and maintained as rapidly as the topology changed.
 Congestion and collision Control: The unbounded network size also creates a
challenge. The traffic load is low in rural areas and night in even urban areas. Due to
this, the network partitions frequently occurs while in rush hours the traffic load is
very high and hence network is congested and collision occurs in the network.
 Environmental Impact: VANETs use the electromagnetic waves for communication.
These waves are affected by the environment. Hence to deploy the VANET the
environmental impact must be considered.
 MAC Design: VANET generally use the shared medium to communicate hence the
MAC design is the key issue. Many approaches have been given like TDMA, SDMA,
and CSMA etc. IEEE 802 adopted the CSMA based Mac for VANET.
 Security: As VANET provides the road safety applications which are life critical
therefore security of these messages must be satisfied.

Vehicle-to-vehicle (V2V) is an automobile technology designed to allow automobiles
to “talk” to each other. The systems will use a region of the 5 GHz band set aside by the
United States Congress in 1999, the unlicensed frequency also used by WiFi.

V2V is currently in active development by General Motors, which demonstrated the
system in 2006 using Cadillac vehicles. Other automakers working on V2V
include Toyota, BMW, Daimler, Honda, Audi, Volvo and the Car-to-Car communication
consortium.

Providing vehicle–vehicle and vehicle–roadside communication can considerably
improve traffic safety and comfort of driving and traveling. For communication in vehicular
ad hoc networks, position-based routing has emerged as a promising candidate. For Internet
access, Mobile IPv6 is a widely accepted solution to provide session continuity and
reachability to the Internet for mobile nodes. While integrated solutions for usage of Mobile
IPv6 in (non-vehicular) mobile ad hoc networks exist, a solution has been proposed that, built
upon a Mobile IPv6 proxy-based architecture, selects the optimal communication mode
(direct in-vehicle, vehicle–vehicle, and vehicle–roadside communication) and provides
dynamic switching between vehicle–vehicle and vehicle–roadside communication mode
during a communication session in case that more than one communication mode is
simultaneously available.

Currently there is ongoing research in the field of InVANETs for several scenarios.
The main interest is in applications for traffic scenarios, mobile phone systems, sensor
networks and future combat systems. Recent research has focused on topology related
problems such as range optimization, routing mechanisms, or address systems, as well as
security issues like traceability or encryption. In addition, there are very specific research
interests such as the effects of directional antennas for InVANETs and minimal power
consumption for sensor networks. Most of this research aims either at a general approach to
wireless networks in a broad setting or focus on an extremely specific issue.

IV. BLUETOOTH AND ADHOC WIRELESS NETWORKS

Bluetooth is one of the technologies that can be used for ad hoc networking.
Bluetooth specification is a computing and telecommunications industry specification that
describes how e. mobile phones, computers, and personal digital assistants (PDAs) can
easily interconnect and communicate with each other by using wireless transmission in a
short-range. The goal of the specification is to eliminate the need for any cable connectivity
and promote ad hoc networking. By using this technology, users of cellular phones, laptops,
PDAs, etc. portable devices can quickly share information with each other, for example, in a
conference room using ad hoc networking.

IV Point to Point Application

Point to point connection is the very basic functionality of the Bluetooth technology.
It is not exactly the main interest of us when talking about Bluetooth ad hoc networks, indeed
it can said that it is more like ad hoc connection than network. However, some key issues of
Bluetooth usability in piconets with a single slave should be noted to understand how it is
performing in the area where it is originally plant to be used. This helps us to understand the
future availability of Bluetooth enabled devices in general.

Point to point connectivity with Bluetooth is obviously an alternative for cable
connectivity. However, it is clearly not an option as replacement of every type of cable
connections. The data transmission rates that Bluetooth is currently designed to support are
not suitable for high capacity connections. Connections using over 723 kbps data
transmission rates will most probably not be replaced by Bluetooth simply for the sake of
having a wireless connection.

Computer industry is today widely supporting the Universal Serial Bus (USB) cabling
standard for chaining peripherals together. Currently USB is enabling data transmission rates
up to 12 Mbps. Any peripheral whose performance is less than satisfactory over such a
connection is probably not going to benefit from a wireless link running at less than a tenth of
this capacity. The next version of USB is expected to run at 480 Mbps with the aim of being
able to support digital video. After this there is clearly even less ground for Bluetooth
technology to work as a USB replacement.

The same goes for the IEEE 1394 standard, also known as Firewire and iLink. This
standard enables connections which runs at speed of 400 Mbps in true peer to peer fashion
and are being adopted by the consumer video products industry for the likes of camcorders
and as a wired networking solution to pipe video round the home from a residential gateway.
Again, Bluetooth is no alternative here.

However, as well as supporting much higher capacities and not being mobile these
technologies are a different kind of options from Bluetooth. These standards are essentially
high speed but also mainly unidirectional, as they allow only very limited bandwidth used for
signaling purposes towards the other direction. Bluetooth supports a much greater degree of
interactivity and will be best deployed where this two-way capability is required such as
voice and information retrieval applications.

In general, Bluetooth is well suitable in point to point applications demanding, or
highly benefiting of, wireless connectivity. Good examples of this kind of applications are
mobile terminal headsets and dial-up networking between laptop and mobile terminal.

Fig 4: Single piconet ad hoc network.

Firstly there is the fact that although the slaves can come and go as they want and the
application will handle these dynamics as expected, if the master leaves the piconet the whole
network drops down. It is clear that this is a problem in applications like used as an example
here. It needs extra work from the users of the ad hoc network to decide a proper master that
will be available for the whole time.

Secondly, with up to seven devices paging the master at once there are likely to be a
considerable number of collisions leading to an increased network formation time. Still the
effect of this might not be so dramatic because the fact that often the slaves won?t be joining
into the network at the same time but with some time variance.

Finally, loss of bandwidth will result due to the way in which the piconet is formed.
Normally a connection will have to be initiated by the slave with a master/slave switch
occurring once the connection is made. This requires the master to continuously be in page
scan mode, which will consume up to 10% of the available bandwidth. In the case of the
fixed LAN access point this is simply part of the application it is serving, it is constantly
being on the lookout for new devices that may want to connect to the network. But in the

group networking situation when the number of participants in the network will be known at
the setup, as an example a meeting of few person, there will be no need for the master to visit
page scan mode once all participants have joined. If there is no facility to switch this mode
off then the application will be saddled with a significant loss of bandwidth.

As conclusion of Bluetooth usage for a simple, piconet size, ad hoc networking it can
be noted that there are few problems that are not currently solved and that effect to
performance of Bluetooth specification to work as ad hoc networking technology. The
presented problems are not however showstoppers for Bluetooth usage in simple, e.
meeting kind of, ad hoc networking application.

In general it can still be seen that the Bluetooth technology suits well in this kind of
small, piconet sized, ad hoc networks as it does not need any cable connectivity and offers
moderate bandwidth for data transmission. Next we look into scatternet topology that extends
Bluetooth application usage over the limit of piconet?s eight simultaneously active nodes.

IV Scatternet Application

The concept of the scatternet is integral part of Bluetooth specification and has been
under a remarkable research interest since first introduced. Anyone new to Bluetooth will be
introduced to the concept of the scatternet almost immediately; the topology employed by
Bluetooth is that of a master and slave forming a piconet and piconets in turn can be linked to
create a scatternet covering a much wider area.

Indeed, scatternets are suggested as being preferential to a point to multipoint piconet
as the AU System?s Bluetooth White paper suggests; <if a mobile user wants to connect a
number of Bluetooth units to his mobile phone, the best way to get high data transmission
capacity is to form as many piconets as possible in one scatternet. Every connection is using a
piconet?s maximum capacity (721 kbps).=

Sound good in theory, but the reality is that the scatternet functionality to date is still
essentially that – just theory. Many observers claim that the scatternet functionality is not
defined precisely enough in the Bluetooth specification to ensure interoperability and that that
as a result many developers of Bluetooth radios are not even attempting to implement it.
Furthermore none of the existing profiles support scatternet functionality.

Also this situation is being remedied by the PAN Working Group, which is extending
Bluetooth to provide true IP-based personal area networking capability, which will involve
tightening up the scatternet specification. Making scatternets work via a profile in this way,
as opposed to altering the radio or base-band specification is necessary in order to maintain
the basic stability of the version 1 of the specification.

the Internet as well as receive packets from the Internet and route them back into the mesh
network. It is possible to use a regular laptop or a mobile phone with a 3G/4G data service
plan to operate as the gateway for the mesh nodes.

The gateway concept introduces a bottleneck through which all Internet packets are
routed. In most impoverished areas, this is already a limited resource. SPAN does not need
the Internet to operate as its own off-grid communications network. The bandwidth of the
WiFi between phones is significant without having to access the Internet at all. Therefore, the
focus of 3WDroid, particularly in a many node mesh network needs to focus upon
downloadable apps that can be routed between nodes within the mesh rather than moving
packets through the gateway.

SPAN has already developed a voice chat application that leverages this intranet
concept which would be essential to a successful relief operation. Giving 3WDroid users a
free voice communication tool to others in the WiFi network is itself a great application. (It
would be nice to develop a texting intranet application as well). The point is that there are
many Android applications that can be written that don?t need the Internet at all and 3WDroid
hopes to crowd source development of such applications as it emerges from being a startup.

For example, the following are 3 applications:

1. Educational applications

The successful emergence of the massive open on-line curriculum
companies(MOOC?s) such as Coursera, Ed-X, Khan Academy and Udacity into the 3WDroid
network would be huge. The implementation details need to be worked out but one can
envision hosting courses on a proxy server at the gateway end-point or at other points within
the mesh network (solar powered Ubuntu laptops). Or, individual phones/tablets can
download individual courses that could be streamed in a peer-to-peer fashion over the mesh
network.

2. Medical applications

The target population of 3WDroid has very little access to clinics or doctors or any
medical care of any sorts. Providing access to medical knowledge can be a significant

improvement to enhancing whatever little medical care the population already has. Hosting a
proxy medical question/answer application could be a great life enhancer.

3. Offline Market Place

Most of the target population of 3WDroid leads subsistence lifestyles eking out a
living from whatever limited resources are available to them. An online marketplace that
supports a barter transactional system could significantly alter the economics of an
impoverished area – seeds for food; clothes for produce; etc

CONCLUSION

Recent trends in compact computing and wireless technologies are expansion of ad hoc
network. Ad hoc network consists of versatile flat forms which are free to move
expeditiously. Ad hoc networks are multi-hop network that use wireless communication for
transmission without any fixed infrastructure. The networks are form and deform on-the-fly
without the need for any system. Ad hoc structure does not require an access point, it is easy
to setup, especially in a small or temporary network. Each node in the network forwards the
packet without the need of central administration. In ad hoc network, node acts as a router to
send and receive the data. An advantage of the system is robustness, flexibility and mobility.
Due to these reasons there are several applications of ad hoc wireless network. Ad hoc
network are capable for analyzing radio propagation environment to optimize the
performance. This typically requires that the network node have positioning capability as
well as memory to recall geographical local condition. An ad hoc network typically refers to
any set of network where all devices have equal status on a network and are free to associate
with any other ad hoc network device in link range. Ad hoc network often refers to a mode of
operation of IEEE802 wireless networks.