TY - JOUR
T1 - Performance analysis of coordinated cognitive radio networks under fixed-rate traffic with hard delay constraints
AU - Castellanos-López, S. Lirio
AU - Cruz-Pérez, Felipe A.
AU - Rivero-Ángeles, Mario E.
AU - Hernández-Valdez, Genaro
PY - 2014/4
Y1 - 2014/4
N2 - Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.
AB - Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.
KW - Call admission control
KW - Coordinated cognitive radio networks
KW - Erlang capacity
KW - New call blocking and call forced termination probabilities
KW - QoS
KW - Spectrum leasing
KW - Stringent delay sensitive traffic
UR - http://www.scopus.com/inward/record.url?scp=84900866836&partnerID=8YFLogxK
U2 - 10.1109/JCN.2014.000023
DO - 10.1109/JCN.2014.000023
M3 - Artículo
SN - 1229-2370
VL - 16
SP - 130
EP - 139
JO - Journal of Communications and Networks
JF - Journal of Communications and Networks
IS - 2
ER -