[Kulkarni, 2(12): December, 2013] ISSN: 2277-9655 Impact Factor: 1.852 http: // www.ijesrt.com(C)International Journal of Engineering Sciences & Research Technology [3408-3411] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY TECHNOLOGY Collision Avoidance Algorithm with Jitter in Multi-hop Cognitive Radio Network Rakesh Kulkarni *1 , Makarand Jadhav 2 , Sanjay Koli 3 *1,2 Sinhgad college of engineering,Pune, India 3 SKN College of engineering,Pune,India 2006.kulkarni@gmail.com Abstract Cognitive radio techniques make full use of spectrum resources via dynamic spectrum access technique. This paper presents a collision avoidance algorithm with the addition of jitter in multi-hop cognitive network. In a multi-hop Cognitive Radio system in which information needs to be relayed over multiple wireless links and secondary users have to co-ordinate themselves in a distributed manner, an improvement in throughput is achieved by reducing packet loss, through the addition of small jitter 1μs at the time of transmission for a network with a set of 6 nodes. Initially we describe the multi-hop cognitive radio network then various issues for Design of system are considered. From the result it is observed that the throughput for a multi-hop cognitive radio network achieved up to 28x 103 bits/s with the set values of 6 nodes. Keywords: Throughput, Cognitive radio, collision, jitter Cognitive Radio Network Cognitive radio, which enables secondary users/networks to utilize the spectrum when primary users are not occupying it, has been a promising technology to improve spectrum utilization efficiency. Spectrum sensing to detect the presence of the primary users is, therefore, a fundamental requirement in cognitive radio networks.[1] Due to high fluctuations in available spectrum as well as the diverse quality of service requirements of various applications. Each CR user in the CR network must determine which portions of the spectrum are available and detect the presence of licensed users when a user operates in a licensed band, select the best available channel , coordinate access to this channel with other users and vacate the channel when a licensed user is detected.[2] This can be realised through spectrum management functions given below: A. Spectrum sensing: A CR user can allocate only an unused portion of the spectrum .Therefore, a CR user should monitor the available spectrum bands, capture their information and then detect Spectrum holes. B. Spectrum decision: Based on spectrum availability, CR users can allocate a channel to meet user communication requirements. C. Spectrum sharing: Because there may be multiple users trying to access the spectrum, CR network access should be co-ordinated to prevent multiple users colliding in overlapping portions of the spectrum. D. Spectrum mobility: If the specific portion of the spectrum in use is required by a primary user, the communication must be continued in another vacant portion of the spectrum. The emerging IEEE 802.22 standard-based wireless regional area network (WRAN) technology is based on the single-hop CRN concept, in which a centralized cognitive base station (BS) manages the SUs that opportunistically use the TV bands when they are unoccupied by the incumbent TV services. On the other hand, multi-hop CRNs (MHCRN) have no fixed network infrastructure or central controller with an additional requirement that the information needs to be relayed over multiple wireless links. Thus, the SUs in a MHCRN have to coordinate themselves in a distributed manner Design of System A node is an entity which acts as host (eg. A source or destination) and a router (an intermediate node).it receives packets from attached application and forwards them to the attached links specified in the routing table. The network is made up of two types of components: nodes and communication lines. The nodes typically handle the network protocols and provide switching capabilities. A node is usually itself a computer (general or special) which runs specific network software. For a cognitive radio system, a node can be configured as a primary user (licensed) or a