The existing works in CRAHN
routing protocols can be classified based on their support for the following : (i) routing with spectrum decision, that is, joint spectrum selection with the choice of the next hop forwarding node, (ii) routing with joint spectrum decision and PU awareness, where the CUs are able to identify the locations of PUs and route around them as in , and (iii) routing with joint spectrum decision and reconfigurability, where the route can be adapted with local spectrum changes or by selecting a different set of forwarding nodes altogether.
De acuerdo con la arquitectura de la red, las redes de radio cognitiva pueden clasificarse en redes basadas en infraestructura o redes de radio cognitiva ad hoc (CRAHNs
) (Akyildiz et al., 2006).
Cognitive radio ad hoc networks (CRAHNs
) are networks with mobile CR devices working without the support of any fixed infrastructure or central administration.
The dynamic and multi-hop nature of CRAHN
communication impacts the stability of path to these gateways.
Example 2: Consider a multi-hop CRAHN
(cognitive radio ad hoc network) shown in Figure 5, with nodes S and D as the source and destination nodes respectively (adapted from ).
For this reason, the Defense Advanced Research Projects Agency (DARPA) is seeking to meet future military needs based on CR Ad Hoc Networks (CRAHNs
It is expected that compared to one-hop CRNs, TCP will encounter more serious difficulty in providing end-to-end communications in multi-hop CRNs, such as CR ad hoc networks (CRAHNs
)  -infrastructureless, self-organizing multi-hop networks, and lacking centralized network management.
In the paradigm of Cognitive Radio Ad Hoc Networks (CRAHNs
), SUs can communicate with each other in ad hoc manner through both available licensed and unlicensed spectrum bands without relying on a preexisting infrastructure , resulting in the ubiquitous connectivity, minimal configuration, quick deployment and improved network scalability.
Then, we present our contribution in this paper which consists in implementing a parallel dynamic programming algorithm on a multi-core architecture applied in CRAHNs
. We also implement cuckoo search and compare it to our dynamic programming implementation using threads.
Chowdhury (2009), "CRAHNs
: Cognitive Radio Ad Hoc Networks," Ad Hoc Networks, vol.7, pp.810-836.
Hamdi, "Harnessing Frequency Domain for Cooperative Sensing and Multi-channel Contention in CRAHNs
," IEEE Trans.
A dynamic and weighted spectrum decision mechanism based on SNR Tracking in CRAHNs
. El Sevier, Ad Hoc Networks, 752-759.