8 research outputs found

    Control Adaptativo de Admisi贸n e Interferencia en redes de Radio Cognitiva con Tr谩fico El谩stico

    Full text link
    [EN] The scope of this study is to design an adaptive admission control system to limit the interference caused by the unlicenced or secondary users to the licenced or primary users on cognitive radio networks. This mechanism allows to set an objective for interference probability beforehand, assuring a certain level of quality of service to the primary users. On the other hand, an objective for abandonment probability is also established to the secondary users due to impacience, assuring as well a certain level of quality of service to them, as it is more disturbing to be cut in the middle of a transmission than to be banned from starting it. Although there are several studies about interference analysis on cognitive radio from a traffic perspective, it is the first one using adaptive schemes when the primary traffic is real time (voice) and the secondary traffic is elastic (data).Roig Roig, PJ. (2012). Control Adaptativo de Admisi贸n e Interferencia en redes de Radio Cognitiva con Tr谩fico El谩stico. http://hdl.handle.net/10251/27337.Archivo delegad

    Practical Spectrum Aggregation for Secondary Networks With Imperfect Sensing

    Full text link

    Voice Capacity and Data Response Time in Cognitive Radio Networks

    Get PDF
    The growing interest towards wireless communication services over the recent years has increased the demand for radio spectrum. Inefficient spectrum management together with the scarcity of the radio spectrum is a limiting factor for the development of modern wireless networks. As a solution, the idea of cognitive radio networks (CRNs) is introduced to use licensed spectrum for the benefit of the unlicensed secondary users. However, the preemptive priority of the licensed users results in random resource availabilities at the secondary networks, which makes the quality-of-service (QoS) support challenging. With the increasing demand for elastic/interactive data services (internet based services) and wireless multimedia services, QoS support becomes essential for CRNs. This research investigates the voice and elastic/interactive data service support over CRNs, in terms of their delay requirements. The packet level requirements of the voice service and session level delay requirements of the elastic/interactive data services are studied. In particular, constant-rate and on-off voice traffic capacities are analyzed over CRNs with centralized and distributed network coordination. Some generic channel access schemes are considered as the coordination mechanism, and call admission control algorithms are developed for non-fully-connected CRNs. Advantage of supporting voice traffic flows with different delay requirements in the same network is also discussed. The mean response time of the elastic data traffic over a centralized CRN is studied, considering the shortest processor time with and without preemption and shortest remaining processor time service disciplines, in comparison with the processor sharing service discipline. Effects of the traffic load at the base station and file length (service time requirement) distribution on the mean response time are discussed. Finally, the relationship between the mean response times of interactive and elastic data traffic is studied

    Sesi贸n 495, Ordinaria Modalidad Virtual. Vig茅simo Cuarto Consejo Acad茅mico, 12 de julio de 2022

    Get PDF
    1 archivo PDF (305 p谩ginas) + 1 archivo zipLista de asistencia. -- Orden del D铆a. -- Acta de la Sesi贸n 495 Ordinaria. -- Acuerdos de la Sesi贸n 495 Ordinaria. -- Acta de la Sesi贸n 494. -- Jurados Diploma a la Investigaci贸n 2021. -- Renuncias Comisiones Dictaminadoras Divisionales (Dr. Ernesto Rodrigo V谩zquez Cer贸n, Mtro. Fabricio Vanden Broeck y Dr. Le贸n Tom谩s Ejea Mendoza). -- Dictamen creaci贸n de 脕rea Mec谩nica -- Dictamen Premio a las 脕reas 2022 -- Escrito DCSH.AZC.336.22 Dictamen C. Docencia Consejo Divisional CSH. -- Escrito suscrito por el Dr. Sa煤l Jer贸nimo Romero con fecha 11 de julio de 2022 y anexos. -- Escrito con fecha 12 de julio de 2022 firmado por un grupo del sector estudiantil relativo a la petici贸n de un di谩logo p煤blico con el Rector de la Unidad Azcapotzalco

    Cognitive Radio Networks with Elastic Traffic

    No full text
    We model and evaluate an infrastructure based cognitive radio network where impatient unlicensed or secondary users (SUs) offer elastic traffic. The interference created by SUs to the licensed users is analyzed when the secondary network uses two different spectrum access schemes, the conventional random access scheme and a new scheme we refer to as access with preference. To further control the interference, a limit is set to the number of channels SUs have access to. With this new constraint, the abandonment probability, the mean delay and throughput of the SUs degrades significantly. To improve the QoS perceived by the active SUs, we define and evaluate an admission control scheme for the SUs

    Cognitive Radio Networks with Elastic Traffic

    No full text
    We model and evaluate an infrastructure based cognitive radio network where impatient unlicensed or secondary users (SUs) offer elastic traffic. The interference created by SUs to the licensed users is analyzed when the secondary network uses two different spectrum access schemes, the conventional random access scheme and a new scheme we refer to as access with preference. To further control the interference, a limit is set to the number of channels SUs have access to. With this new constraint, the abandonment probability, the mean delay and throughput of the SUs degrades significantly. To improve the QoS perceived by the active SUs, we define and evaluate an admission control scheme for the SUs
    corecore