5 research outputs found
Band Allocation for Cognitive Radios with Buffered Primary and Secondary Users
In this paper, we study band allocation of buffered secondary
users (SUs) to orthogonal primary licensed bands, where each
primary band is assigned to one primary user (PU). Each SU is assigned to one
of the available primary bands with a certain probability designed to satisfy
some specified quality of service (QoS) requirements for the SUs. In the
proposed system, only one SU is assigned to a particular band. The optimization
problem used to obtain the stability region's envelope (closure) is shown to be
a linear program. We compare the stability region of the proposed system with
that of a system where each SU chooses a band randomly with some assignment
probability. We also compare with a fixed (deterministic) assignment system,
where only one SU is assigned to one of the primary bands all the time. We
prove the advantage of the proposed system over the other systems.Comment: Accepted in WCNC 201
On Orthogonal Band Allocation for Multi-User Multi-Band Cognitive Radio Networks: Stability Analysis
In this work, we study the problem of band allocation of buffered
secondary users (SUs) to primary bands licensed to (owned by)
buffered primary users (PUs). The bands are assigned to SUs in an orthogonal
(one-to-one) fashion such that neither band sharing nor multi-band allocations
are permitted. In order to study the stability region of the secondary network,
the optimization problem used to obtain the stability region's envelope
(closure) is established and is shown to be a linear program which can be
solved efficiently and reliably. We compare our orthogonal allocation system
with two typical low-complexity and intuitive band allocation systems. In one
system, each cognitive user chooses a band randomly in each time slot with some
assignment probability designed such that the system maintained stable, while
in the other system fixed (deterministic) band assignment is adopted throughout
the lifetime of the network. We derive the stability regions of these two
systems. We prove mathematically, as well as through numerical results, the
advantages of our proposed orthogonal system over the other two systems.Comment: Conditional Acceptance in IEEE Transactions on Communication
Resource Allocation in Heterogeneous Buffered Cognitive Radio Networks
Resources available for operation in cognitive radio networks (CRN) are generally limited, making it imperative for efficient resource allocation (RA) models to be designed for them. However, in most RA designs, a significant limiting factor to the RA’s productivity has hitherto been mostly ignored, the fact that different users or user categories do have different delay tolerance profiles. To address this, in this paper, an appropriate RA model for heterogeneous CRN with delay considerations is developed and analysed. In the model, the demands of users are first categorised and then, based on the distances of users from the controlling secondary user base station and with the assumption that the users are mobile, the user demands are placed in different queues having different service capacities and the resulting network is analysed using queueing theory. Furthermore, to achieve optimality in the RA process, an important concept is introduced whereby some demands from one queue are moved to another queue where they have a better chance of enhanced service, thereby giving rise to the possibility of an improvement in the overall performance of the network. The performance results obtained from the analysis, particularly the blocking probability and network throughput, show that the queueing model incorporated into the RA process can help in achieving optimality for the heterogeneous CRN with buffered data
Band allocation for cognitive radios with buffered primary and secondary users
In this paper, we study band allocation of Ms buffered secondary users (SUs) to Mp orthogonal primary licensed bands, where each primary band is assigned to one primary user (PU). Each SU is assigned to one of the available primary bands with a certain probability designed to satisfy some specified quality of service (QoS) requirements for the SUs. In the proposed system, only one SU is assigned to a particular band. The optimization problem used to obtain the stability region's envelope (closure) is shown to be a linear program. We compare the stability region of the proposed system with that of a system where each SU chooses a band randomly with some assignment probability. We also compare with a fixed (deterministic) assignment system, where only one SU is assigned to one of the primary bands all the time. We prove the advantage of the proposed system over the other systems. 2014 IEEE.Scopu