CROSS-LAYER DESIGN IN MOBILE (VEHICULAR) AD HOC NETWORKS: ISSUES AND POSSIBLE SOLUTIONS

Abstract

The Vehicular Ad hoc Network (VANET) is a type of Mobile Ad hoc Network (MANET) that is distinguished by its high-speed mobility, restricted movement patterns, high node density in urban areas, and low node density in rural areas. Vehicle Adhoc networks, an emerging technology in automobiles, play a critical role in ensuring road safety. It's a type of smart transportation system. However, with VANETs, changing network architecture and rapid vehicular movement constitute a concern since they cause packet losses and latency, lowering QoS. (QOS). Cross-layer design is used in VANET architecture because it allows information to be exchanged across all layers. This paper examines the various difficulties that mobile ad-hoc networks face (mostly specific to VANETS) I. INTRODUCTION With the rise of mobile devices, cutting infrastructure costs while retaining the same degree of connection became critical. MANETs (mobile ad-hoc networks), which rely on wireless communication between devices, are at a crossroads. Ad Hoc Networks, which are devoid of any infrastructure or central management, is called after a Latin word that means "for this purpose alone." Military rescue, disaster assistance following an earthquake, sensors for measurement in regions inaccessible to people, and other uses demanded a network with little infrastructure, resulting in the development of Mobile ad hoc networks (MANETs) [2]. MANETs were restricted to computing devices and electronics until the emergence of Intelligent transportation systems, which focus on vehicular connectivity and safety and are all wireless. VANETS (Vehicular Ad-Hoc Networks) is the term for this sort of network, which primarily refers to the usage of MANET technology for vehicular communication. In VANETS, vehicles and other roadside items communicate with one another. As a hybrid network, VANETS may connect with both automobiles and infrastructures [3]. Because VANET is a subset of MANET, it contains all of MANET's features, such as self-management, peer-to-peer communication, self-configuration, and a dynamic topology that consumes less bandwidth. VANETS support two forms of communications: vehicle-to-vehicle communication (V2V) and vehicle-to-vehicle communication (V2V). The other is Vehicle to Infrastructure (V2I), which is concerned with communication between a vehicle and permanent infrastructures (such as gateways, base stations, and other devices located beside highways to assist vehicles)[4]. Fig. 1. Vehicle to vehicle (V2V) and vehicle to infrastructure (V2I)[5] A. ARCHITECTURE OF VANETS The architecture of VANETs is divided into the following categories: 1)Wireless Local Area Network(WLAN): The architecture in which automobiles communicate with each other through cellular networks. The automobiles in this architecture can communicate with one another via a roadside unit. The cars can only communicate with vehicles within the RSU's radius and cannot connect with vehicles outside the RSU's radius.. Fig. 2. Vehicle to infrastructure[6] 2) Adhoc: In this architecture, vehicles communicate with one another using ad hoc networks. The vehicles may send, receive, and forward messages from one vehicle to another,

Full text

CROSS-LAYER DESIGN IN MOBILE
(VEHICULAR) AD HOC NETWORKS:
ISSUES AND POSSIBLE SOLUTIONS
Rampalli Lakshmi Sree Alekhya
Dept. of Electronics
Carleton University
Ottawa, Canada
Abstract: The Vehicular Ad hoc Network (VANET) is
a type of Mobile Ad hoc Network (MANET) that is
distinguished by its high-speed mobility, restricted
movement patterns, high node density in urban areas, and
low node density in rural areas. Vehicle Adhoc networks,
an emerging technology in automobiles, play a critical
role in ensuring road safety. It's a type of smart
transportation system. However, with VANETs, changing
network architecture and rapid vehicular movement
constitute a concern since they cause packet losses and
latency, lowering QoS. (QOS). Cross-layer design is used
in VANET architecture because it allows information to
be exchanged across all layers. This paper examines the
various difficulties that mobile ad-hoc networks face
(mostly specific to VANETS)
I . INTRODUCTION
With the rise of mobile devices, cutting infrastructure
costs while retaining the same degree of connection became
critical. MANETs (mobile ad-hoc networks), which rely on
wireless communication between devices, are at a
crossroads. Ad Hoc Networks, which are devoid of any
infrastructure or central management, is called after a Latin
word that means "for this purpose alone." Military rescue,
disaster assistance following an earthquake, sensors for
measurement in regions inaccessible to people, and other
uses demanded a network with little infrastructure, resulting
in the development of Mobile ad hoc networks (MANETs)
[2]. MANETs were restricted to computing devices and
electronics until the emergence of Intelligent transportation
systems, which focus on vehicular connectivity and safety
and are all wireless. VANETS (Vehicular Ad-Hoc
Networks) is the term for this sort of network, which
primarily refers to the usage of MANET technology for
vehicular communication. In VANETS, vehicles and other
roadside items communicate with one another. As a hybrid
network, VANETS may connect with both automobiles and
infrastructures [3]. Because VANET is a subset of MANET,
it contains all of MANET's features, such as self-
management, peer-to-peer communication, self-
configuration, and a dynamic topology that consumes less
bandwidth.
VANETS support two forms of communications:
vehicle-to-vehicle communication (V2V) and vehicle-to-
vehicle communication (V2V). The other is Vehicle to
Infrastructure (V2I), which is concerned with
communication between a vehicle and permanent
infrastructures (such as gateways, base stations, and other
devices located beside highways to assist vehicles)[4].
Fig. 1. Vehicle to vehicle (V2V) and vehicle to infrastructure (V2I)[5]
A. ARCHITECTURE OF VANETS
The architecture of VANETs is divided into the following
categories:
1)Wireless Local Area Network(WLAN): The architecture
in which automobiles communicate with each other through
cellular networks. The automobiles in this architecture can
communicate with one another via a roadside unit. The cars
can only communicate with vehicles within the RSU's
radius and cannot connect with vehicles outside the RSU's
radius. .
Fig. 2. Vehicle to infrastructure[6]
2) Adhoc: In this architecture, vehicles communicate with
one another using ad hoc networks. The vehicles may send,
receive, and forward messages from one vehicle to another,

acting as a router. The drawback with this technology is
that it cannot be used to exchange messages if the distance
between the cars is too great.
Fig. 3. Routing Based[6]
3)Hybrid: This method is a combination of the two
methods described above. In this technique, the cars may
communicate with one another utilizing both ad-hoc and
cellular networks. Cars may employ both ways depending
on their demands thanks to this technology.
Fig. 4. VANET's component and communication[7]
B. Application of VANETs
The applications of VANETs can be put into two types:
1) Safety-related applications: - These applications are
time-sensitive, and time is very crucial in these
applications. For example, in the event of an accident, it is
critical to transmitting messages to other vehicles on the
same road, as this can save a lot of time. It also aids in
traffic congestion reduction by sending a message to
vehicles, allowing them to take a different path, reducing
traffic congestion on the road.
2) Non-safety-related applications: - Although these
applications are not time-sensitive, they nevertheless
necessitate a great amount of data. Video streaming is a
popular example of this type of application. This service
allowed individuals to watch videos in their cars. Vehicles
can obtain information about nearby gas stations or
restaurants via non-safety-related services. QOS is one of
the ways to assess the service's quality.
C. CHALLENGES IN VANETs
1) Authentication: In VANETs, there is no central entity
that can verify message authenticity. Messages are
transmitted from one vehicle to the next, and there is no
means to verify if the message is genuine or not.
2) High Mobility: VANETs were created to bring non-
safety and safety applications to on-the-road cars.
However, because of the network's dynamic nature,
providing these applications to vehicles at a consistent rate
is difficult. Because the trucks are traveling at such a high
pace, messages are lost and signals are intermittent.
3) Location-based services: It is challenging to provide
location-based services in VANETs since the vehicles are
constantly changing direction at a very high speed and on
a regular basis. Providing these services to automobiles is
difficult.
4) Real-time system: One of the most important benefits
supplied by VANETS to automobiles is safety-related
applications. However, the dynamic nature of the process
makes it difficult to provide these services to the vehicles.
Lack of real-time data might result in not just property
damage, but also death.
5) Coverage area: When compared to SDN, where a bigger
region can be covered, VANETGs can only cover a smaller
area. Important messages, such as emergency messages,
can only be exchanged in a smaller region as a result of this.
II. MANETS DESIGN
Mobile ad hoc Network (MANET) has its own architecture
[8] depicted in the figure. The architecture is
subcategorized as follows:
• Enabling technologies;
• Networking;
• Middleware and applications
Fig. 5. Architecture of MANET [8].
A. Enabling Technologies
Body Area Network (BAN), Personal Area Network
(PAN), Local Area Network (LAN), and Wide Area
Network (WAN) are several types of enabling technologies
in MANET [9]. A body area network (BAN) connects
devices such as microphones and earphones that are within
a 1-2 meter range. Personal area networks (PAN) are in
charge of linking mobile devices to one another. Wireless
LANs (WLANs) make it possible to connect one or more
buildings. Many concerns, such as location management

and security, must be addressed in metropolitan-area
(MAN) ad hoc networks.
B. Networking
This is the most significant layer of the MANET
architecture, as it includes the majority of the
functionalities. The basic goal is to use one-hop
transmission from the enabling technologies to deliver data
from the sender to the receiver. The sender's role is to use
a location services map to map the receiver's true and
logical location to the present one.
C. Middleware and Applications
The third section of the architecture is primarily concerned
with network location services and memory sharing among
multiple mobile devices. We can also see that, as time has
passed and mobile network technology has advanced,
many new technologies have been launched in domains
such as disaster management, IoT, sensor networks,
institutional purposes, traffic control, home networking,
and so on. Apps are now in charge of their own resources
and services, and new mobile ad hoc systems are being
developed without the use of middleware.
Mobile ad hoc networks have recently gained a lot of
popularity due to the increasing use of mobile phones and
various mobile accessories. As a result, the number of
mobile ad hoc network applications in numerous industries
will increase. Mobile Radio Networking, Mesh
Networking, and Multihop Wireless Networking [10] are
all technologies that are related to this one. Effective data
interchange in the industrial and commercial sectors is one
of MANET's most essential uses. These networks can be
utilized as a cost-effective alternative to cell-based
networks, and they offer a variety of benefits in military
and IP-compliant applications [11]. MANET technology
has recently been used in the construction of wearable
devices. Because of its varied nature of communication,
MANET technology may also be utilized for disaster relief,
traffic safety, and firefighting.
III. VANETS DESIGN
The number of automobiles on the road is increasing every
day. Smart cars, vehicle tracking systems, entertainment,
and GPRS systems are just a few of the uses for vehicular
ad hoc networks. This, among other things, provides road
safety and traffic control. VANETs, or vehicle ad hoc
networks, are a subset of MANETs that employ autos as
network nodes [12]. These networks enable data transfer
between a range of neighboring autos and roadside devices
efficiently [13]. VANETs are similar to MANETs in that
they lack infrastructure, have reduced capacity, and have a
limited data transmission range [12]. MANET protocols,
on the other hand, cannot be directly used in VANET
owing to the increased mobility of automobiles over mobile
devices, since they result in low convergence, poor
communication, and network disruption [14], [15], and
[16]. Obstacles such as homes, buildings, trees, and traffic
signals obstruct vehicles, resulting in poor channel and
connection quality [17].
Fig. 6. Vehicular AD Hoc Network [18].
Vehicular ad hoc networks are classified as ad hoc, cellular,
or a combination of the two [19]. As seen in [20], VANET
employs a variety of communication methods.
Vehicle to Vehicle (V2V): This sort of communication
allows cars to communicate with one another.
Vehicle to Infrastructure (V2I): V2I is concerned with the
efficient transfer of data between vehicles and fixed
infrastructure such as gateways and base stations deployed
on the road [21]. Vehicle to Road Equipment (V2R)
communication is another name for it.
To provide safe and efficient traffic, a Hand-off design was
implemented in MIMO-enabled WLANs for
Communication-based Train Control Systems (CBTC) in
[24]. This was accomplished through the integration of
wireless communication into the standard ground control
system. It also outlines how to create protocols for ad hoc
networks. VANETs have a variety of uses, including
computing within vehicles, forecasting vehicle position,
danger sensing applications, and the ability to send data
continually [26]. This is conceivable provided the vehicle
is always moving and we have sufficient road information.
Furthermore, these qualities can be extremely beneficial to
the government, automobile manufacturers, and customers
[25].
IV. CROSS LAYER DESIGN IN VANET
A. Cross-Layer Design in Wireless Networks
In an analysis of cross-layer designs in wireless networks,
Fu et al. [22] discovered that cross-layer designs primarily
address three issues: security, quality of service, and
mobility. As indicated in Fig. 5, they try to enhance one,
two, or all three of them independently or simultaneously.
To ensure layer abstraction and internal implementation
concealing, the rigorous layer architecture allows
information to be transferred only between neighboring
levels and only through well-specified interfaces [23].

Fig. 7. The goals of cross-layer designs [22]
Cross-layer designs allow information flow to be directed
directly between nonadjacent layers in the Non-manager
approach, as shown in Fig. 8a, or through a vertical
information exchange plane in the Manager technique, as
shown in Fig. 8b, in violation of layered design principles.
Furthermore, information sharing across layers can be
internal or external. Manager method refers to cases where
a vertical control plane is introduced to be responsible for
the information exchange by serving as a database where
all layers contribute and retrieve information to and from
as needed (Fig. 8b), and non-Manager method refers to
cases where layers are directly responsible for the exchange
of information between each other without intermediaries
(Fig. 8a).
Fig. 8 Manager and Non-Manager methods of cross-layer designs [22]
Cross-layer information exchange can be divided into
internal and external techniques from the perspective of the
network. External methods refer to information sharing
between different nodes in a network, while internal
methods refer to the information exchange within the layers
of each node internally, employing manager or non-
manager modes. External designs are further divided into
centralized and distributed designs, with centralized cross-
layer designs storing information centrally in one node and
distributed designs distributing data across several entities.
Cross-layer information exchange occurs over the network
in both circumstances, and nodes share cross-layer
information with one another [27].
B. Cross-layer routing
The majority of routing research in the literature focuses on
tiered ad hoc network routing, ignoring any knowledge
about wireless channel characteristics that may be present
at lower levels. The performance loss of layered routing
architecture in VANET [28] is due to separate decision-
making at various tiers. There have been several suggested
ad hoc routing protocols, which may be divided into three
categories: proactive, reactive, and hybrid [29], [30].
Proactive protocols vary from reactive protocols in that
they store routing tables in each node and listen to hello
messages from each node on a frequent basis to keep routes
to all potential destinations defined. When a transmission
demand develops, these pre-built routing tables assist in
minimizing route discovery time. However, if the
network's number of nodes becomes too high, it may
become hard to store the whole routing table in each node.
Source-driven reactive protocols, on the other hand, send
route discovery packets only when enough data has been
gathered for transmission. As a result, reactive routing
nodes record only the routes to destination nodes that are
intended for transmission, regardless of the total number of
nodes in the network. Hybrid techniques, on the other hand,
try to seek a middle ground between the two approaches
[30]. Many routing protocols were created to exploit
information accessible at various protocol stack tiers to
achieve a balance between routing table size, route
discovery time, and wireless channel conditions. They can
be categorized into the following groups:
1) Position-Based Routing Protocols
Position-based routing systems make decisions about how
to send packets based on current and next-hop position
information collected from sources such as the Global
Positioning System (GPS). Greedy forwarding, trajectory-
based forwarding, contention, opportunistic forwarding,
and hybrid forwarding are all examples of forwarding
systems [31].
2) Broadcast Protocols
To forward packets, broadcast-based routing methods use
multi-hop broadcasting and rebroadcasting. In its most
basic form, this strategy could result in broadcast storms,
extreme congestion, contention, redundant broadcasts, and
collisions. Location-Based Broadcasting (LBB) [32],

Urban Multi-hop Broadcast (UMB) [33], Ad-hoc Multi-
hop Broadcast (AMB) [34], and Multi-Hop Vehicular
Broadcast (MHVB) [35] are some of the innovations
developed specifically for VANET to mitigate these side
effects.
3) Geocast Routing Protocols
GVGrid Protocol [36], Distributed Robust Geocast (DRG)
[37], and RObust VEhicular Routing (ROVER) protocol
[37] are examples of protocols built specifically for the
need to reach a specified geographic region with a specific
QoS utilizing a combination of scheduling and directed
flooding.
4) Hierarchical Routing Protocols
Because not all nodes are involved in routing, only the
cluster head and edge gateways are responsible for
executing the routing function, cluster-based routing
protocols reduce packet delivery overhead and increase the
number of successful packet deliveries. In a highly
dynamic VANET network, this strategy shifts the burden
from managing broadcast storms to the process of selecting
cluster heads and gateways [31].
5) Adaptive and Context-Aware Routing Protocols
This group of protocols employs contextual data about
network circumstances to choose the optimum routes in
terms of performance, latency, packet loss, and other
factors. Some of the protocols based on this method are Ant
Colony Optimization (ACO) [38], Adaptive Connectivity
Aware Routing (ACAR) [39], and Prediction-Based
Topology Control and Routing in Cognitive Radio Mobile
Ad Hoc Networks [40].
C. Physical Layer – MAC Layer Cross-Layer Designs
In wired networks, the physical layer's responsibility is
largely confined to sending and receiving data on a shared
or dedicated media when the top layers request it. Signal
processing advances are allowing the physical layer to
execute more jobs than a pure OSI model architecture
would allow [41]. Most cross-layer solutions between the
physical and mac layers that are being proposed for
wireless networks in general, such as Hybrid Automatic
Repeat Request (HARQ) and Adaptive Modulation
Control, can be employed in VANETs as well (AMC). The
MAC layer uses the information available to the physical
layer, such as backoff time slots and BER, to select the
optimal frame size for the specific channel conditions. For
WiMAX, Chiu et al. presented a cross-layer quick
handover approach in which physical layer information is
communicated with the MAC layer [42]. The Vehicular
Fast Handover Scheme (VFHS) reduced the time between
handovers. V. Saritha and V. Madhu Viswanatham
proposed a cross-layer based channel reservation with pre-
emption (CCRP) method in [43], in which the physical
layer's handoff time estimates in vehicular ad hoc networks
are communicated to the mac layer, which then performs
the channel allocation process based on the handoff time
estimates.
D. MAC Layer – Network Layer Cross-Layer Designs
Chen et al. [44] presented a routing protocol called Cross-
layer Ad hoc On-demand Routing as an example of cross-
layer design between the MAC layer and the network layer
in VANET applications. R-AOMDV with Demand
Multipath Distance Vector (R-AOMDV) with Demand
Multipath Distance Vector (R-AOMDV) with Demand
measure for retransmission counts The routing is done in
this protocol. Both hop counts from the network layer are
taken into account when making a choice at the network
layer. the network layer, as well as MAC retransmission,
counts route selection using a layer In [45], Chen et al.
proposed a framework that integrated the network and the
mac in a useful way layer protocols to minimize packet loss
and ensure QoS In mobile ad hoc networks, data traffic
with a higher priority is prioritized. Routing hop counts and
multi-queue scheduling are taken into account by the
framework. Nasri et al. presented a cross-layer design in
which the MAC layer is skipped in certain circumstances
and packets are transmitted straight to the physical layer to
reduce latency in time-sensitive urgent traffic intersection
emergency notifications [46].
Fig. 9 Cross-layer Cluster Based Forwarding (CCBF)[47]
In their paper [47], Wiegel et al. suggested a Cross-layer
Cluster Based Forwarding (CCBF) routing protocol in
which cars form clusters and elect a cluster head for each
cluster. Cluster heads are in charge of keeping the medium
access control schedule up to date, ensuring that each
cluster member transmits only during the time slot and
channel given to it by the cluster head. The MAC layer is
primarily responsible for cluster generation and
management, but the resulting cluster structure is shared by
the MAC and network levels, as seen in Fig. 7. The MAC
layer handles packet forwarding within the cluster, whereas
the network layer handles packet forwarding between
clusters.

V. ISSUES AND SOLUTIONS
A. Quality of Service (QoS) in MANET
The measurement of the system's overall efficiency and
performance, as well as the information offered to the user,
is referred to as quality of service (QoS). It's challenging to
provide high-quality service on mobile ad hoc networks
[48]. It's important to keep in mind that throughput, error
rate, and latency all contribute to the ideal QoS. As a result,
in order to increase data transmission, it is critical to
maintaining the system's quality in accordance with the
demands of the users. The optimum path for transmitting
data is determined via QoS routing. Bandwidth Reservation
and Mobility-based Predictive Call Admission Control [49]
are two mobile ad hoc network ideas that emphasize
quality.
Fig. 10. QoS in Wireless ad hoc network [50].
Assume a bandwidth of 4 Mbps is required to transport a
data packet from point A to point C. The network is
involved in determining the best path for data transmission.
It's known as Quality of Service (QoS) routing. One option
that fits the bandwidth constraint is A-B-C.
Fig. 11. Hidden Terminal Problem.
There are a host of obstacles when it comes to QoS
implementation [51]. The dynamic topology of the mobile
ad hoc network might be one of the most challenging
challenges since this network consists of devices that are
never stationary, occasionally leave the network, and new
additions to the network. As a result, deciding on the best
way for transmitting the data packet becomes incredibly
difficult. Because there is no central management, meeting
QoS criteria is also incredibly challenging. It's also worth
noting that because the network channel is shared among
the nodes, establishing QoS is quite challenging. Due to
limited resources like as storage, bandwidth, and energy,
maximum QoS cannot be achieved. The problem of
concealed terminals is also a big concern. This may be
described with the assistance of an illustration. Assume
node B can receive signals from nodes A and C, but not
from node A or vice versa. This is owing to the fact that
nodes A and C have differing transmission ranges.
The following methods [51] can be used to solve the
challenges listed above. There are two forms of QoS
reservations: hard state resource reservation, in which
resources are preserved as long as data is transferred
between sender and receiver, and soft-state resource
reservation, in which resources are saved as long as data is
transferred between sender and receiver. Soft state
reservation, on the other hand, sets aside resources for a
fixed period of time. Second, both stateful and stateless
approaches can be used to handle the problem of dynamic
topology. Nodes in a stateful approach are well aware of
state information (topology information). As a result,
determining the best data transmission method becomes
easy. Finally, the user specifies the amount of time that the
QoS requirements should be met. The quality of services is
necessary for the entire transmission in Hard QoS. Soft
QoS, on the other hand, only requires services for a limited
length of time during transmission.
B. Congestion Control
The use of vehicle ad hoc networks has risen
substantially as the number of cars on the road continues to
rise (VANETs). As a result, critical transmission channels
are required in order to convey data swiftly, effectively, and
safely. The authors investigated a number of issues in
vehicle ad hoc networks in [52]. This research looked at the
standard OSI approach, which employs three lower levels
to communicate data. As a result, service quality degrades.
On the other hand, effective communication between levels
is essential to improve performance. This is done through
the use of cross-layer design. Cross-layer design is
employed to achieve this. In terms of minimizing system
congestion and choosing the best route to transport
information between endpoints, the Mac, network, and
physical layers give the greatest performance outcomes.
[53] goes through a number of different congestion issues.
Mobility, the diverse type of nodes, and traffic and
movement topology all contribute to congestion problems
in VANETs.
The authors S. V. Sangolli and J. Thyagarajan discuss
the potential for congestion in mobile ad hoc networks in
[53]. (MANETs). Because all devices in the mobile ad hoc
network have a set transmitting range, nodes on the
transmission line can receive data from the sender. If the
mobile devices go disconnected from the transmission
range and the link is broken during the transmission process,
data is lost. This occurs due to transmission loss caused by
mobile device movement and if the device is out of battery
or power. Similarly, in the TCP paradigm, data loss is an
example of system congestion. As a result, a congestion
control system has been devised as a remedy.

C. Multipath Routing
VANETs (Vehicular Ad hoc Networks) require a routing
protocol to limit the number of accidents and boost
efficiency by minimizing system delays and retransmission
times. Because of the frequent movement of the nodes or
vehicles, single-path routing in VANETs presents issues
due to a break in the communicative link between the nodes
and the base station [54].
Because a single-path system reduces the system's
performance, fault tolerance can occur. To address this
problem, a cross-layer routing technique called CLMR is
used in conjunction with RAID (Redundant Array
Inexpensive Disks) to improve QoS [54].
There are three types of RAID parities, each of which
necessitates the use of a cross-layer design to facilitate
protocol interaction and improve data transmission. They
are:
1) Distributed parity on a single path.
2) Distributed parity on many paths. Parity on many paths
3) Parity with two distributions.
The following are the measures to take:
STEP 1: At the application layer, find the disjoint points of
the nodes with their bandwidth on different paths and
compare them.
STEP 2: Subtract the available bandwidth from the
necessary bandwidth.
STEP 3: The traffic from the application layer also shows
how RAID works.
For vehicle-to-vehicle communication, Yufeng Chang
proposes a multipath routing protocol in [55]. R-AODMV
is a transmission counts and hop counts-based cross-layer
design algorithm. It performs routing metric selection at the
MAC layer and then produces a routing table in RREP or
RRETRAN format with an entry schedule [55].
D. Dynamic Topology
MANETs feature a dynamic topology, which implies that
the locations of mobile devices and nodes in the network
change over time and with changes in geographic location.
The topology of the network changes as a result, resulting
in data loss and transmission delays. By allowing for
greater communication between detached layers while
retaining a high transmission range, the cross-layer design
can help to address the challenge of dynamic topology.
[56] discusses topology control and routing challenges in
Cognitive Radio, as well as an approach for using cognitive
capabilities for routing called Prediction-based Cognitive
Topology Control (PCTC). For Routing, this acts as a
cross-layer design. The authors of [57] discuss Mixed-
control Topology management for mobile ad hoc networks,
which is used to manage highly dynamic networks by
combining two controllers to avoid short-term network
failures.
E. Information Security
There are several challenges based on the security of the
mobile ad hoc network due to the lack of central
administration, changeable topology, and open data flow
inside the network (MANET). In order to avoid security
threats, it is critical to have a high level of user
authentication [58]. There are obvious distinctions between
wired networks and MANET wireless networks, and as a
result, all mobile devices are vulnerable to attacks both
inside and outside the network. Furthermore, because the
network consists of a huge number of modes, it is
impossible to take care of each individual node in the
network, it is extremely difficult to locate the node under
assault inside the network. The issue of security can be
addressed using a decentralized strategy in which each
node is assigned a super node, ensuring that even if one
node is attacked, the others remain safe. However, the
centralized strategy is not the same as the one described
above. If one node is attacked, the entire system will fail.
Because there are no limits in a mobile ad hoc network, it
is more vulnerable to assault. At the same time, the
decentralized strategy prevents the detection of network
attacks and attackers [59].
The following are the various security issues in MANETs
[60]:
• Confidentiality - The information should be kept
private and accessible only to those who have
been given permission.
• Authentication - Unauthorized network access
should be avoided at all costs.
• Access Control - This controls which node has
access to which information.
• Integrity - The recipient should have complete
confidence in and knowledge of the verified data
received.
• Availability - It should be highlighted that the
information should be available to the user at all
times, including during a DoS assault.
Cross-layer design, which provides information access
between two separate levels, can be used to identify the
attacked and affected nodes. As a result of the cross-layer
architecture, Wireless Ad Hoc Networks, Wireless Sensor
Networks, and Wireless Mesh Networks improve their
overall performance and security [61].
F. Energy Efficiency and Conservation
Consider Flying Ad Hoc Networks (FANETs), which are
wireless sensor networks with a limited amount of energy
because they are designed to last indefinitely. It should be
mentioned that in networks where no protocols for
recharging batteries exist, the issue of energy efficiency is

quite essential. As a result, battery extension is a viable
option for maintaining energy efficiency in these networks.
Energy harvesting protocols for these networks are
discussed by the authors in [62]-[65].
R. Xie, F. Richard Yu, H. Ji, and Y. Li provide energy
efficiency ways in [66], which exploit the whole cognitive
capability of the Mobile ad hoc network by giving macro
and femtocell cognitive capabilities. [67] also mentions
other factors that impact energy during data transmission
across the network channel, such as traffic. Based on these
factors, MTEC and ACW have been established, which
give a channel contention possibility and a relationship
between the distance between nodes and the signal
intensity to assess the network's energy use.
Fig. 12. MTEC and ACW Algorithms Energy Graph [67].
As a result, the signal strength deteriorates as the distance
between the nodes expands, demanding care. Energy
consumption is calculated using the energy-conscious
routing protocol, based on the quantity of retransmitted
data and the number of channel contention. The MTEC
protocol is primarily concerned with reducing the
network's energy consumption and, as a result, extending
its lifespan.
CONCLUSION
VANET is a novel technology that is being propelled
forward by advances in wireless networks, as well as a
growing interest in connected cars, autonomous vehicles,
and road safety. To maintain the safety and security of the
cars on the road, the packet must be transferred
appropriately. As a result, choosing the appropriate routing
condition can have a big influence on performance. The
issues that Vehicular Ad-Hoc Networks and Mobile Ad-
Hoc Networks face are numerous. The most common
issues we see with VANETs stem from their extremely
dynamic nature (caused because of High mobility). For
wired networks, traditional stacking works nicely, but not
so much for wireless networks (particularly wireless adhoc
networks). The most effective solutions for tackling all of
the issues in VANETs and MANETs appear to be cross-
layer design strategies. Cross layer architecture provides
flexible solutions to problems by safely sending data over
the network channel in order to improve system
performance. There are still some challenges to overcome.
REFERENCES
[1] K. Govindan and P. Mohapatra, "Trust computations and trust
dynamics in mobile adhoc networks: A survey," IEEE
Communications Surveys & Tutorials, vol. 14, no.2, pp. 279-298,
2012.
[2] D. Djenouri, L. Khelladi and A. N. Badache, "A survey of security
issues in mobile ad hoc and sensor networks," in IEEE
Communications Surveys & Tutorials, vol. 7, no. 4, pp. 2-28, Fourth
Quarter 2005. DOI: 10.1109/COMST.2005.1593277.
[3] Zaydoun Yahya and Syed Masud. “Communications in Vehicular Ad
Hoc Networks”. In: Mobile Ad-Hoc Networks: Applications (Mar.
2011). DOI: 10 . 5772 /13399.
[4]Ehsan Soleimani-Nasab, Mehrdad Ardebilipour, andMahdi Kashih.
“cross layer design in Wireless Ad Hoc Networks with Multiple
Antennas”. In: Mobile Ad-Hoc Networks: Protocol Design (2011).
DOI: 10.5772/12863.
[5] Parrado et al. Congestion Based Mechanism for RouteDiscovery in a
V2I-V2V System Applying Smart Devices and IoT. Mar. 2015.
URL: https://www.mdpi.com/1424-8220/15/4/7768/html.
[6] aadil, farhan & rizwan, shahzad & akram, adeel, "vehicular ad
hocnetworks (vanets), past present and future: a survey", (2013)
theseventh international working conference, at craiglands hotel,
ilkley,west yorkshire, england, uk
[7] i. Ku, y. Lu, m. Gerla, r. L. Gomes, f. Ongaro and e.
Cerqueira,"towards software-defined vanet: architecture and
services," 201413th annual mediterranean ad hoc networking
workshop (med-hocnet),piran, 2014, pp. 103-110.
[8] J.S. Mehta, S. Nupur and S. Gupta, “An Overview of MANET:
Concepts, Architecture & Issues” International Journal of Research
in Management, Science & Technology, vol. 3, no. 2, pp. 121-125,
April. 2015.
[9] R. Ramanathan, and J. Redi, "A brief overview of ad hoc networks:
challenges and directions," IEEE communications Magazine, vol.
40, no. 5, pp. 20-22, 2002.
[10]Macker and Joseph. "Mobile ad hoc networking (MANET): Routing
protocol performance issues and evaluation considerations," 1999.
[11]B. Adamson, "Tactical radio frequency communication requirements
for Ipng," 1994.
[12] A. Awang, K. Husain, N. Kamel and S. Aïssa, "Routing in Vehicular
Ad-hoc Networks: A Survey on Single- and Cross-Layer Design
Techniques, and Perspectives," in IEEE Access, vol. 5, pp. 9497-
9517, 2017, DOI: 10.1109/ACCESS.2017.2692240.
[13] M. Sivasakthi and SR. Suresh. "Research on vehicular ad hoc
networks (VANETs): an overview," International Journal of
Applied Science and Engineering Research, vol. 2, no. 1, pp. 23-27,
2013.
[14]B. Jarupan and E. Ekici, „„A survey of cross-layer design for
VANETs,‟‟ Ad Hoc Netw., vol. 9, no. 5, pp. 966–983,
[15]R. Stanica, E. Chaput, and A. L. Beylot, „„Properties of the MAC
layer in safety vehicular ad hoc networks,‟‟ IEEE Commun. Mag.,
vol. 50, no. 5, pp. 192–200, May. 2012.
[16]H. Trivedi, P. Veeraraghavan, S. Loke, A. Desai, and J. Singh,
„„Routing mechanisms and cross-layer design for vehicular ad hoc
networks: A survey,‟‟ in Proc. IEEE Symp. Comput. Inform. (ISCI),
pp. 243–248, Mar. 2011.
[17] W. Liang, Z. Li, H. Zhang, S. Wang, and R. Bie, „„Vehicular ad hoc
networks: Architectures, research issues, methodologies, challenges,
and trends,‟‟ Int. J. Distrib. Sensor Netw, vol. 2015, pp. 1–11, Jan.
2015.
[18]S. Rehman, M. A. Khan, T. A. Zia, and L. Zheng, "Vehicular Ad-Hoc
Networks (VANETs)-An Overview and Challenges." Journal of
Wireless Networking and Communications, no. 3, pp. 29-38, 2013.
[19] C. Jeremiah and A. J. Nneka, "Issues and possibilities in Vehicular
Ad-hoc Networks (VANETs)," 2015 International Conference on
Computing, Control, Networking, Electronics and Embedded
Systems Engineering (ICCNEEE), Khartoum, pp. 254-259, 2015,
DOI: 10.1109/ICCNEEE.2015.7381372.
[20] P. Fazio, F. De Rango and C. Sottile, "A Predictive Cross-Layered
Interference Management in a Multichannel MAC with Reactive
Routing in VANET," in IEEE Transactions on Mobile Computing,
vol. 15, no. 8, pp. 1850-1862, 1. Aug. 2016, DOI:
10.1109/TMC.2015.2465384.

[21] B. Jarupan and E. Ekici, „„A survey of cross-layer design for
VANETs,‟‟ Ad Hoc Netw., vol. 9, no. 5, pp. 966–983,
[22] B. Fu, Y. Xiao, H. J. Deng, and H. Zeng, “A Survey of Cross-
LayerDesigns in Wireless Networks,” IEEE Commun. Surv. Tutor.,
vol. 16,no. 1, pp. 110–126, 2014.
[23] F. Foukalas, V. Gazis, and N. Alonistioti, “Cross-layer design
proposalsfor wireless mobile networks: a survey and taxonomy,”
IEEE Commun. Surv. Tutor., vol. 10, no. 1, 2008.
[24] L. Zhu, F. Richard Yu, B. Ning, and T. Tang, “Cross-Layer Handoff
Design in MIMO Enabled WLANs for Communication-Based Train
Control (CBTC) Systems,” IEEE J. Sel. Areas in Comm. (JSAC),
vol. 30, no. 4, pp. 719-728, Mar. 2012.
[25] H. Kathiriya, N. Kathiriya and A. Bavarva, "Review on V2R
Communication in VANET," Proceedings of International
Conference on Innovations in Automation and Mechatronics
Engineering, pp. 21-23, Feb. 2013.
[26] H. Moustafa, and Y. Zhang,” Vehicular networks: techniques,
standards, and applications,” Auerbach publications, 2009.
[27] F. Foukalas, V. Gazis, and N. Alonistioti, “Cross-layer design
proposalsfor wireless mobile networks: a survey and taxonomy,”
IEEE Commun.Surv. Tutor., vol. 10, no. 1, 2008.
[28] H. Trivedi, P. Veeraraghavan, S. Loke, A. Desai, and J. Singh,
“Routing mechanisms and cross-layer design for vehicular ad hoc
networks: A survey,” in Computers & Informatics (ISCI), 2011
IEEE Symposium on, 2011, pp. 243–248.
[29] E. M. Royer and C.-K. Toh, “A review of current routing protocols
for ad hoc mobile wireless networks,” IEEE Pers. Commun., vol. 6,
no. 2,pp. 46–55, 1999.
[30] J. Zuo, C. Dong, S. X. Ng, L.-L. Yang, and L. Hanzo, “Cross-Layer
Aided Energy-Efficient Routing Design for Ad Hoc Networks,”
IEEE Commun. Surv. Tutor., vol. 17, no. 3, pp. 1214–1238, 2015.
[31] H. Trivedi, P. Veeraraghavan, S. Loke, A. Desai, and J. Singh,
“Routing mechanisms and cross-layer design for vehicular ad hoc
networks: A survey,” in Computers & Informatics (ISCI), 2011
IEEE Symposium on, 2011, pp. 243–248.
[32] Q. Xu, R. Segupta, D. Jiang, and D. Chrysler, “Design and analysis
of highway safety communication protocol in 5.9 GHz dedicated
short range communication spectrum,” in Vehicular Technology
Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual,
2003, vol. 4, pp.2451–2455.
[33] G. Korkmaz, E. Ekici, F. Özgüner, and Ü. Özgüner, “Urban multi-
hop broadcast protocol for inter-vehicle communication systems,”
in
Proceedings of the 1st ACM international workshop on Vehicular ad hoc
networks, 2004, pp. 76–85.
[34] G. Korkmaz, E. Ekici, and F. Ozguner, “An efficient fully ad-hoc
multihop broadcast protocol for inter-vehicular communication
systems,” in Communications, 2006. ICC’06. IEEE International
Conference on, 2006, vol. 1, pp. 423–428.
[35] T. Osafune, L. Lin, and M. Lenardi, “Multi-hop vehicular broadcast
(MHVB),” in ITS Telecommunications Proceedings, 2006 6th
International Conference on, 2006, pp. 757–760.
[36] W. Sun, H. Yamaguchi, K. Yukimasa, and S. Kusumoto, “Gvgrid: A
qos routing protocol for vehicular ad hoc networks,” in Quality of
Service, 2006. IWQoS 2006. 14th IEEE International Workshop on,
2006, pp. 130–139.
[37] M. Kihl, M. Sichitiu, and H. P. Joshi, “Design and evaluation of two
geocast protocols for vehicular ad-hoc networks,” J. Internet Eng.,
vol. 2, no. 1, 2008.
[38] S. S. Manvi, M. S. Kakkasageri, and C. V. Mahapurush,
“Performance Analysis of AODV, DSR, and Swarm Intelligence
Routing Protocols In Vehicular Ad Hoc Network Environment,”
2009, pp. 21–25.
[39] Q. Yang, A. Lim, S. Li, J. Fang, and P. Agrawal, “ACAR: Adaptive
connectivity aware routing protocol for vehicular ad hoc networks,”
in Computer Communications and Networks, 2008. ICCCN’08.
Proceedings of 17th International Conference on, 2008, pp. 1–6.
[40] Q. Guan, F. R. Yu, S. Jiang, and G. Wei, “Prediction-Based Topology
Control and Routing in Cognitive Radio Mobile Ad Hoc Networks,”
IEEE Trans. Veh. Technol., vol. 59, no. 9, pp. 4443–4452, Nov. 2010.
[41] V. Srivastava and M. Motani, “Cross-layer design: a survey and the
road ahead,” IEEE Commun. Mag., vol. 43, no. 12, pp. 112–119,
2005.
[42] K.-L. Chiu, R.-H. Hwang, and Y.-S. Chen, “Cross-layer design
vehicle aided handover scheme in VANETs,” Wirel. Commun.
Mob. Comput., vol. 11, no. 7, pp. 916–928, Jul. 2011.
[43] V. Saritha and V. Madhu Viswanatham, “An efficient cross layer
based channel reservation method for vehicular networks: Efficient
Cross Layer based Channel Reservation Method,” Int. J. Commun.
Syst., vol. 27, no. 12, pp. 4249–4264, Dec. 2014.
[44] Y. Chen, Z. Xiang, W. Jian, and W. Jiang, “A Cross-Layer AOMDV
Routing Protocol for V2V Communication in Urban VANET,”
2009,pp. 353–359.
[45] X. Chen, S. Qiang, Z. GuoAn, and B. ZhiHua, “A Novel Framework
for QoS Enhancement in Ad Hoc Network,” in Wireless
Communications,Networking and Mobile Computing, 2006.
WiCOM 2006. International Conference on, 2006, pp. 1–4.
[46] A. Nasri, M. Fathy, and R. Hajisheykhi, “A cross layered scheme for
broadcasting at intersections in vehicular ad hoc networks,” in
Future Networks, 2009 International Conference on, 2009, pp. 13–
17.
[47] B. Wiegel, Y. Gunter, and H. P. Gro\s smann, “Cross-layer design
for packet routing in vehicular ad hoc networks,” in Vehicular
Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th,
2007, pp. 2169–2173.
[48] Corson, M. Scott. "Issues in supporting quality of service in mobile
ad hoc networks." Building QoS into Distributed Systems. Springer,
Boston, MA, 1997, pp. 131-134.
[49] F. Yu and V.C.M. Leung, “Mobility-Based Predictive Call
Admission Control and Bandwidth Reservation in Wireless Cellular
Networks,” in Proc. IEEE INFOCOM’01, Anchorage, Alaska, April
2001.
[50]T. Bheemarjuna Reddy, I. Karthigeyan, B.S. Manoj, C. Siva Ram
Murthy, "Quality of service provisioning in ad hoc wireless
networks: a survey of issues and solutions" Ad Hoc Networks, pp.
83–124, 2004.
[51]T. Bheemarjuna Reddy, I. Karthigeyan, B.S. Manoj, C. Siva Ram
Murthy, "Quality of service provisioning in ad hoc wireless
networks: a survey of issues and solutions" Ad Hoc Networks, pp.
83–124, 2004.
[52]A. Awang, K. Husain, N. Kamel and S. Aïssa, "Routing in Vehicular
Ad-hoc Networks: A Survey on Single- and Cross-Layer Design
Techniques, and Perspectives," in IEEE Access, vol. 5, pp. 9497-
9517, 2017, DOI: 10.1109/ACCESS.2017.2692240.
[53]S. V. Sangolli and J. Thyagarajan, "An efficient congestion control
scheme using cross-layered approach and comparison of TCP
variants for mobile ad-hoc networks (MANETs)," 2014 First
International Conference on Networks & Soft Computing
(ICNSC2014), Guntur, 2014, pp. 30-34.
[54]P. V. Krishna, V. Saritha, G. Vedha, A. Bhiwal and A. S. Chawla,
"Quality-of-service-enabled ant colony-based multipath routing for
mobile ad hoc networks," in IET Communications, vol. 6, no. 1, pp.
76-83, 4 January 2012. DOI: 10.1049/iet-com.2010.0763
[55]Y. Chen, Z. Xiang, W. Jian and W. Jiang, "A Cross-Layer AOMDV
Routing Protocol for V2V Communication in Urban VANET," 2009
Fifth International Conference on Mobile Ad-hoc and Sensor
Networks, Fujian, 2009, pp. 353-359.
[56] Q. Guan, F. Richard Yu, S. Jiang, and G. Wei, “Prediction-Based
Topology Control and Routing in Cognitive Radio Mobile Ad Hoc
Networks,” IEEE Trans. Vehicular Technology, vol. 59, no. 9, pp.
4443-4452, Nov. 2010.
[57] M. Carvalho, A. Granados, S. Subramanian and C. Perez, "A cross-
layer approach to mixed-control topology management for
MANETs," 2010 - MILCOM 2010 Military Communications
Conference, San Jose, CA, 2010, pp. 411-416.
[58] K.K.Lakshmi Narayanan, A.Fidal Castro, “High Security for Manet
Using Authentication and Intrusion Detection with Data Fusion”
International Journal of Scientific & Engineering Research Volume
3, Issue 3, March -2012 1 ISSN 2229-5518
[59] Wenjia Li and Anupam Joshi, “Security Issues in Mobile Ad Hoc
Networks - A Survey” The, 2007 - cs.umbc.edu
[60]K.K.Lakshmi Narayanan, A.Fidal Castro, “High Security for Manet
Using Authentication and Intrusion Detection with Data Fusion”
International Journal of Scientific & Engineering Research Volume
3, Issue 3, March -2012 1 ISSN 2229-5518
[61]A. Singh and G. Singh, “Security in Multi-hop Wireless Networks”
IJCST Vol. 2, Issue 2, June 2011 International Journal of Computer

Science and Technology ISSN: 2229 - 4333 (Print) | ISSN: 0976 -
8491
[62] G. Xiong, L. Hong and Y. Guangyou, "Improving energy efficiency
by optimizing relay nodes deployment in wireless sensor networks,"
2017 IEEE 9th International Conference on Communication
Software and Networks (ICCSN), Guangzhou, China, 2017, pp.
306-310.
[63] R. Aouami, M. Rifi and M. Ouzzif, "Improve the energy efficiency
in wireless sensor networks fountain code theory," 2017 8th IEEE
Annual Information Technology, Electronics and Mobile
Communication Conference (IEMCON), Vancouver, BC, 2017, pp.
582-587.
[64] M. T. Rahama, M. Hossen and M. M. Rahman, "A routing protocol
for improving energy efficiency in wireless sensor networks," 2016
3rd International Conference on Electrical Engineering and
Information Communication Technology (ICEEICT), Dhaka, 2016,
pp. 1-6.
[65] S. Kaur and R. Goel, "A review on data transmission techniques for
energy efficiency in Wireless Sensor Networks," 2016 International
Conference on Wireless Communications, Signal Processing and
Networking (WiSPNET), Chennai, 2016, pp. 699-703. DOI:
10.1109/WiSPNET.2016.7566223.
[66] R. Xie, F. Richard Yu, H. Ji, and Y. Li, “Energy-Efficient Resource
Allocation for Heterogeneous Cognitive Radio Networks with
Femtocells,” IEEE Trans. Wireless Comm., vol. 11, no. 11, pp.
3910-3920, Nov. 2012.
[67] C. Weng, C. Chen, P. Chen and K. Chang, "Design of an energy-
efficient cross-layer protocol for mobile ad hoc networks," in IET
Communications, vol. 7, no. 3, pp. 217-228, February. 2013. DOI:
10.1049/iet-com.2011.0543.