Spectrum Handoffs Based on Preemptive Repeat Priority Queue in Cognitive Radio Networks

Abstract

Cognitive radio can significantly improve the spectrum efficiency, and spectrum handoff is considered as an important functionality to guarantee the quality of service (QoS) of primary users (PUs) and the continuity of data transmission of secondary users (SUs). In this paper, we propose an analytical framework based on a preemptive repeat identical (PRI) M/G/1 queuing network model to characterize spectrum handoff behaviors with general service time distribution of both primary and secondary connections, multiple interruptions and transmission delay resulting from the appearance of primary connections. Then, we derive the close-expression of the extended data delivery and the system sojourn time in both staying and changing scenarios. In addition, based on analysis of spectrum handoff behaviors resulting from multiple interruptions caused by the appearance of the primary connections, we investigate the traffic-adaptive policy, by which the considered SU will optimally adjust its handoff spectrum policy. Moreover, we investigate the admissible region and provide the reference for designing the admission control rule for the arriving secondary connection requests. Finally, simulation results verify that our proposed analytical framework is reasonable and can provide the reference for executing the optimal spectrum handoff strategy and designing the admission control rule for the SU in cognitive radio networks.

Cross‐layer perspective for channel assignment in cognitive radio networks: A survey

“…Further, different probabilities are used by every SU to select a target channel, which may lead to the unfair selection where some SUs may always get channel with best channel gain and other may not. In the similar lines, Yang et al used M/G/1 queuing network model to study the channel handoff behavior of various SUs and corresponding delay in their transmission time because of the varied PU arrival rate. Wang et al proposed some criteria to find the shortest handoff delay for various handoffs.…”

“…Further, different probabilities are used by every SU to select a target channel, which may lead to the unfair selection where some SUs may always get channel with best channel gain and other may not. In the similar lines, Yang et al 76 handoff delay, the decision to stay or to handoff was considered. The idea was to evaluate the total service time for different handoff sequences and to find an optimal sequence; however, it increases the complexity.…”

Performance Study of Queuing Delay in CRN Using Different Proposed Spectrum Handoff Approaches

“…In this paper, three techniques are proposed on a system of one primary user and three secondary users. Change policy, stay policy with resuming the transmission which used Preemptive Resume Priority (PRP) M/ G/1 queuing model [14] and stays with restarting the transmission which used Preemptive Repeat Identical (PRI) M/ G/1 queuing model [15]. The remainder of the paper is organized as follows: Section 2 describes the queuing models.…”

“…The second proposed technique used PRP M/G/1 queuing model [14]. The third proposed technique applied PRI M/G/1 queuing model [15].…”

“…The features of PRI M/G/1 queuing model are [15] are the same features for PRP but the difference is the interrupted secondary user repeats its transmission from the beginning instead of resuming its unfinished transmission.…”