ABSTRACT In cognitive radio network two users


    Mobile Cognitive Ad Hoc
Networks is the one of the cognitive radio networks which is the advanced
networking technologies for spectrum scarcity problem constrain in the Federal
Communication Commission (FCC). The cognitive radio networks are the cognitive
network which abject its network parameters with respect to network
environment. In cognitive radio network two users namely the primary and
secondary or cognitive users will access the available spectrum to communicate
each other when the spectrum is accessed by the primary user the secondary user
must leave the spectrum and access the spectrum when spectrum holes available
for transmission. So routing is challenging issues in cognitive networks and it
is very challenging in mobile cognitive networks due to the node mobility,
primary user interface and spectrum scarcity in this paper some routing
protocols based on mobile ad hoc cognitive networks and a review on the
delay-Minimized routing protocol is presented.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!

order now


Cognitive Radio Networks (CRN), Primary Users (PU), Cognitive
User (CU), Ad Hoc Networks.



Cognitive Radio Networks (CRN) is the new technology used to
overcome the spectrum scarcity problem in current wireless networks by Federal
Communication Commission (FCC). In cognitive radio network is a network which
have primary and secondary users which access the network based on Dynamic
Spectrum Access (DSA). The primary user is the licensed user and secondary user
is unlicensed user when the licensed user is accessing the spectrum the
unlicensed user are not allowed so the secondary user has to sense the spectrum
periodically to find the presence of primary user, presence of primary user is
in dynamic in nature so the spectrum holes created by primary user is dynamic
so the Cognitive user uses the DSA. While using the DSA routing is the
challenging in cognitive radio networks.


of Cognitive radio networks

Cognitive Radio Networks (CRN) is of infrastructured and
infrastructure less, in infrastructured network it has a fixed structure like
base station primary users secondary users and so on, in infrastructured
network it has no fixed structure.

Centralized and Decentralized networks the Centralized
network is the network in which has on base station in the central and have
primary users are present. Decentralized network is the network which has no
centralized base station and has the secondary users to communicate and primary

Static and dynamic networks the static networks the position
of base station, primary users and secondary users are fixed but in the dynamic
(Ad-Hoc) the position on primary users and secondary user will change (Mobility
is nature).


Routing in Cognitive radio networks

in Cognitive radio networks is based on available spectrum and knowledge of
spectrum to nodes in the network. Routing solutions for the Cognitive radio
networks is of two types one is Full Spectrum Knowledge routing and second is
Local Spectrum Knowledge routing.

Local Spectrum Knowledge routing has Minimum Power Routing, Minimum
Delay-based Routing, Maximum Throughput-based Routing, Geographic Routing and
Class-based Routing. This paper is organized in the following manner section 2

Routing protocols in CRN,
section 3 is Routing protocols of Mobile Cognitive Radio Ad-hoc Networks,
section 4 is Delay-Minimized Routing protocols of Mobile Cognitive Radio Ad-hoc
Networks, and section 5 is Conclusion and Future Works.



2.1. Spectrum-Aware Routing

Routing (SPEAR) is a on demand and link based protocol support end-to-end
throughput by integration of flow-based and link-based approaches, it used RREQ
for route discovery by control channels it takes decisions with collaboration
of PHY and MAC layers it handle mobility issues with Timeout field in periodic
channel reservations messages. It takes the best path by maximum throughput,
minimum hop count and link quality it has a communication overhead by route
setup and route tear down.


Spectrum-Aware Mesh Routing (SAMER)

Mesh Routing (SAMER) is a link state routing protocol with minimum hop count
and spectrum availability it gives end-to-end thought with the path with high
spectrum availability, long-term stability and short-term opportunistic
utilization of spectrum. The routing decisions are taken by PHY and MAC layers.


Spectrum-Aware On-Demand Routing Protocol

On-Demand Routing Protocol (SORP) is an AODV protocol with control channel
which uses the path delay and node delay (switching and back off delay) for
path selection. In route discovery phase RREQ message is broadcast with a SOP
append in the packet the control channel exchange the routing protocol messages
and it gives end-to-end thought put SORP doesn’t have link failure handling


Multi-hop Signal-transceiver Cognitive
Radio Network Routing Protocol (MSCRP)

Signal-transceiver Cognitive Radio Network Routing Protocol (MSCRP) is an AODV
protocol with on control channel. It is a spectrum aware routing and leaves/
joins messages of the nodes so it has the communication overhead of RREQ. In
route discovery phase all nodes append their sate information and available
channels set. Routing decision is taken with the collaboration of MAC, Physical
and Network Layers.

Reactive source-based routing Protocol

in Opportunistic Cognitive Radio Networks is an on demand graph structured
network protocol which uses the routing metric based on the probabilistic
definition of available capacity over channel it has no link failure handling
capacity and it discovers the route by using OSPF, Dijkstra-link algorithm. By
using this Dijkstra-link algorithm it gives end-to-end throughput


Local Coordination Based Routing and
Spectrum assignment in Multi-hop Cognitive Radio Networks

Coordination Based Routing and Spectrum assignment in Multi-hop Cognitive Radio
Networks is a modified version of AODV which is on demand routing protocol it
has full mesh topology which uses channel scanning and beacon broadcast for
neighbor discovery with control channel used for load balancing in routing. The
route discovery is done by using RREQ and route decision is based on MAC and
Network Layer. It has link failure handling capability which gives less
end-to-end delay and performance. 


Multipath Routing and Spectrum Access

Routing and Spectrum Access (MRSA) is Mesh routing protocol based on round
robin fashion data striping with minimum hop count by route discovery with
control channel, Broadcasting RREQ messages. The massages sent to nodes
periodically it can handle path failures by sending RERR messages and it has a
communication overhead based on multiple flows on single radio.  


Cognitive Tree-based Routing (CTBR)

Tree-based Routing (CTBR) is the tree based routing protocol with centralized
routing it broadcast the root announcement (RANN) message periodically with a
packet and used cumulative metric for path selection. It selects the path based
on local and global decision schemes. It does not have route recovery mechanism
to handle link failures and it has a control bytes transmission overhead. 




3.1. Fault-Tolerant Cognitive
Ad-Hoc Routing Protocol (FTCARP)

is a fast and efficient routing protocol for route recovery in presence of path
failures during data deliver. It uses different route recovery mechanisms for
different path failures.


Cognitive Destination Sequence Distance
Vector (C-DSDV) Protocol

is a table driven routing protocol. To optimize the system performance of
multi-hop CR ad-hoc networks by using multichannel routing table are updated
immediately when there is change in channels the techniques is that combines
the routing and channel allocation. In route discover phase common control
channel use to broadcast the route updating in the routing table in this
protocol best path selection is based on sequence number. In C-DSDV channel
switching is used to improve the system performances. If there are more primary
users routing over head will be increased 


Cognitive Ad-Hoc On-demand Distance
Vector (C-AODV) Protocol

Ad-Hoc On-demand Distance Vector (C-AODV) Protocol is based on AODV a wireless
network protocol it is designed according to avoid primary users activates
regains for routing formation and packet discovery. It gives the minimized
route cost by forwarding packets through joint path and channel selection at
each node it takes the advantage of availability of multiple channels to
improve the overall performances.


SER-Spectrum and Energy Aware Routing

SER is an on
demand routing protocol which provide high throughput in multi-hop networks it
selects energy efficient route and assign channels and timeslots for connection
request. The communication segment assignment algorithm is used for balances
traffic load among the CR users. In route discovery phase it broadcasts Route
Request Messages to other nodes so it has routing overhead of RRE, RREP, RERR
and ROP messages.

 GYMKHANA Protocol

GYMKHANA is an on
demand routing protocol and enhanced version of AODV used the GYMKHANA
algorithm using virtual graphs and evaluate the cost by using Laplacian matrix.
It has a secondary user’s self-interference over head.



NODE Protocol is a distributed and efficient based interference aware routing
protocol. It incorporates the spectrum availability cost and interference
metrics into the routing algorithm to find better routes between the nodes it
repairs routes by using route preservation method. It provides adaptability to
the environment and increases throughput and reduces data delivery latency.



4.1. ROPCORN Protocol

Protocol is the on demand routing protocol which was designed for data
transportation using link modeling and used to minimized delay for a set of
users in network. It broadcast the packets in link with the low cast and no
primary user is affects. ROPCORN is based on RACON protocol it uses buffers in
the intermediate nodes and forwards the packets there is no overhead due to the
use of spectrum availability and load estimation, the optimal route selection
is based on spatial or temporal locality of link disconnection.


A Routing Protocol

It is the on
demand routing protocol and enhanced version of AODV which is based on the
geographic routing and follow the greedy forwarding and PU avoidance for joint
channel-path optimization algorithm to find the best path. SEARCH undertakes
both the path and selection to avoid PU activity region and tries to maintain
end-to-end latency it has routing overhead due to the RRE, RREP, RERR and ROP


Prediction-Based Adaptive Routing

 Link Prediction-Based Adaptive Routing is
based on link-availability prediction. The link –availability prediction
considers primary user activity and user mobility. This routing reduces the
energy consumption and gives least delay by enhances network performance. It
works based on link prediction and topology control   


Joint Routing and
Channel Assignment

Routing and Channel Assignment (JRCA) approach based on delay prediction
and a heuristic algorithm which used the collision probability and Link
Stability Prediction. It is and on demand routing protocol which user AODV
type of routing with heuristic values and can find out the path with minimal
end-to-end (e2e) delay.



Delay Tolerant Routing Protocol (ADTRP)

 The ADTRP algorithm finds a stable sequence of
instances of the mobile graph and the communication topology of interest such
that the number of transitions from one instance of the topology to another in
the sequence is the global minimum. The algorithm uses the average lifetime of
the mobile graphs in the stable sequence for communication topology and it is a
generic for stable sequence of any communication topology it uses the heuristic
topology for routing so it improved throughput, better packet delivery ratio, decreased
packet drop and reduced delay.



Spectrum-Tree Based On-Demand Routing Protocol


STOD-RP is an on demand routing protocol which was designed for reduces
the control overhead and average end-t-end delay minimization and it is an extension of
the original Ad-hoc On-demand Distance Vector (AODV) protocol which uses
spectrum tree addresses, spectrum decision and route selection in an efficient
way for this route matrix is used. Fast and efficient spectrum-adaptive route
recovery method is used when path is damaged.




In routing is challenging
issues in cognitive networks and it is very challenging in mobile cognitive
networks due to the node mobility primary user interface and spectrum scarcity
this paper conclude that every protocol is designed for overcome certain
problem in networks one is for multiple problems and one is for single problem
like improving performance, minimized end-to-end delay, overall throughput
increasing and so on. There is a for more protocols or improved versions of
protocols for increasing problems and recruitments. In further work on this
paper a delay minimized routing protocol is proposed and implemented that
improved version protocol in NS3 will be presented.