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The well-known fixed-target-signal-to-interference-ratio (SIR)-tracking power control (TPC) algorithm provides all users with their given feasible fixed target SIRs but cannot improve the system throughput, even if additional resources are available. The opportunistic power control (OPC) algorithm significantly improves the system throughput but cannot guarantee the minimum acceptable SIR for all users (unfairness). To optimize the system throughput subject to a given lower bound for the users' SIRs, we present a distributed dynamic target-SIR tracking power control algorithm (DTPC) for wireless cellular networks by using TPC and OPC in a selective manner. In the proposed DTPC, when the effective interference (the ratio of the received interference to the path gain) is less than a given threshold for a given user, that user opportunistically sets its target SIR (which is a decreasing function of the effective interference) to a value higher than its minimum acceptable target SIR; otherwise, it keeps its target SIR fixed at its minimum acceptable level. We show that the proposed algorithm converges to a unique fixed point starting from any initial transmit power level in both synchronous and asynchronous power-updating cases. We also show that our proposed algorithm not only guarantees the (feasible) minimum acceptable target SIRs for all users (in contrast to the OPC) but also significantly improves the system throughput, compared with the TPC. Furthermore, we demonstrate that DTPC, along with TPC and OPC, can be utilized to apply different priorities of transmission and service requirements among users. Finally, when users are selfish, we provide a game-theoretic analysis of our DTPC algorithm via a noncooperative power control game with a new pricing function., QC 20100525

The demand for wireless communications services has increased the amount of spectrum resources required, promoting research interest in dynamic spectrum allocation schemes. There exist many promising solutions to allocate spectrum on a dynamic basis in order to get an efficient spectrum usage. One particular form is auction mechanism, tailored for allocating transmission rights on a short term basis to provide efficient allocation of scarce resources. However, most existing approaches are focused on homogeneous settings where all channels are treated as if they have the same propagation characteristics. In this work we consider two distributed auction schemes; sequential and concurrent, based on sequential ascending and combinatorial bidding, respectively, taking into account the propagation conditions of the channels (heterogeneous settings). The performance of these schemes is compared to two reference cases: (i) distributed homogeneous channels allocation (channel-agnostic case), and (ii) the centralized allocation scheme. Experimental results suggest that auction mechanisms which take into account the channel characteristics improve spectrum utilization under energy constraint. For wireless cellular networks with high unit energy cost (low coverage) concurrent access gives a better utilization of the spectrum and energy resources with higher service providers utility., QC 20110523

The mobile cellular systems are expected to support multiple services with guaranteed Quality of Service(QoS). But, the ability of wireless systems to accommodate expected growth of traffic load and broadband services is limited by available radio frequency spectrum. Call Admission Control (CAC) is one of the resource management functions, which regulates network access to ensure QoS provisioning. However, the decision for CAC is very challenging issue due to user mobility, limited radio spectrum, and multimedia traffic characteristics. To deal with these problems, we implemented a Fuzzy Admission Control System (FACS). We compared the performance of FACS with Shadow Cluster Concept (SCC). In another work, we extended FACS by considering the priority of the on-going connections. We called this system FACS-P. As priority parameter, we considered only one parameter (service request). In this work, we improve our previous system by adding different priorities. We call this system FACS-MP. We evaluate and compare the performance of implemented systems by simulations. From the simulations results, we conclude that the FACS-MP can differentiate better different services compared with previous systems., Peer Reviewed, Postprint (published version)

The mobile cellular systems are expected to support multiple services with guaranteed Quality of Service(QoS). But, the ability of wireless systems to accommodate expected growth of traffic load and broadband services is limited by available radio frequency spectrum. Call Admission Control (CAC) is one of the resource management functions, which regulates network access to ensure QoS provisioning. However, the decision for CAC is very challenging issue due to user mobility, limited radio spectrum, and multimedia traffic characteristics. In our previous work, we proposed a fuzzy-based CAC system by considering the priority of the on-going connections. As priority parameter, we considered only one parameter (service request). In this work, we extend our work by adding different priorities. We call this system FACS-MP. We evaluate by simulations the performance of the proposed system. From the simulations results, we conclude that the FACS-MP can differentiate better different services compared with previous system., Peer Reviewed, Postprint (published version)

Wireless mobile networks and devices are becoming increasingly popular to provide users the access anytime and anywhere. The mobile systems are based on cellular approach and the area is covered by cells that overlap each other. Many handover algorithms are proposed in the literature. However, to make a better handover and keep the QoS in wireless networks is very difficult task. For this reason, new intelligent algorithms should be implemented to deal with this problem. In this paper, we carried out a comparison study of two handover systems based on fuzzy logic. We implement two fuzzy-based handover systems (FBHS). We call them FBHS1 and FBHS2. The performance evaluation via simulations shows that FBHS2 has better behavior than FBHS2 and can avoid ping-pong effect in all simulation cases., Peer Reviewed, Postprint (published version)

Wireless sensor networks (WSN) localization relies on measurements. Availability of, and the information content in, these measurements depend on the network architecture, connectivity, node time synchronization and the signaling bandwidth between the sensor nodes. This chapter addresses wireless sensor networks measurements in a general framework based on a set of nodes, where each node either emits or receives signals. The emitted signal can for example be a radio, acoustic, seismic, infrared or sonic wave that is propagated in a certain media to the receiver. This general observation model does not make any difference between localization of sensor network nodes or unknown objects, or whether the nodes or objects are stationary or mobile. The information available for localization in wireless cellular networks (WCN) is in literature classified as direction of arrival (DOA), time of arrival (TOA), time difference of arrival (TDOA) and received signal strength (RSS). This chapter generalizes these concepts to the more general wireless sensor networks.

The mobile cellular systems are expected to support multiple services with guaranteed Quality of Service (QoS).But, the ability of wireless systems to accommodate expected growth of traffic load and broadband services is limited by available radio frequency spectrum. Call Admission Control (CAC) is one of the resource management functions, which regulates network access to ensure QoS provisioning. However, the decision for CAC is very challenging issue due to user mobility, limited radio spectrum, and multimedia traffic characteristics. In our previous work, we proposed a fuzzy-based CAC system and compared the performance of the proposed system with Shadow Cluster Concept (SCC). In this work, we extend our work by considering the priority of the on-going connections. We evaluate by simulations the performance of the proposed system and compare its performance with our previous work. The performance evaluation shows that the proposed system has a good behavior in keeping the QoS of on-going connections, Peer Reviewed, Postprint (published version)

In this paper, We propose a new call admission control scheme called dual threshold bandwidth reservation, or DTBR scheme. The main novelty is that it builds upon a complete sharing approach, in which the channels in each cell are shared among the different traffic types and multiple thresholds are used to meet the specific quality-of-service (QoS) requirements. We present a detailed comparative study based on mathematical and simulation models, and quantitatively demonstrate that the DTBR is capable of providing the QoS guarantee for each type of traffic, while at the same time leading to much better channel efficiency. We further show that the DTBR scheme with elastic data service can offer both service guarantee and service differentiation for voice and data services, and enhance the bandwidth utilization.

In this paper, We propose a new call admission control scheme called dual threshold bandwidth reservation, or DTBR scheme. The main novelty is that it builds upon a complete sharing approach, in which the channels in each cell are shared among the different traffic types and multiple thresholds are used to meet the specific quality-of-service (QoS) requirements. We present a detailed comparative study based on mathematical and simulation models, and quantitatively demonstrate that the DTBR is capable of providing the QoS guarantee for each type of traffic, while at the same time leading to much better channel efficiency. We further show that the DTBR scheme with elastic data service can offer both service guarantee and service differentiation for voice and data services, and enhance the bandwidth utilization.

In this paper, We propose a new call admission control scheme called dual threshold bandwidth reservation, or DTBR scheme. The main novelty is that it builds upon a complete sharing approach, in which the channels in each cell are shared among the different traffic types and multiple thresholds are used to meet the specific quality-of-service (QoS) requirements. We present a detailed comparative study based on mathematical and simulation models, and quantitatively demonstrate that the DTBR is capable of providing the QoS guarantee for each type of traffic, while at the same time leading to much better channel efficiency. We further show that the DTBR scheme with elastic data service can offer both service guarantee and service differentiation for voice and data services, and enhance the bandwidth utilization.

One of the key issues in the next generation wireless cellular networks is to support multiple services, in which call admission control policy has to guarantee the different Quality of Service (QoS) requirement from diverse applications, and at the same time ensure the scarce bandwidth be utilized efficiently. In this paper, we first build upon our proposed Dual Threshold Bandwidth Reservation (DTBR) scheme to integrate more realistic, variable data traffic, and then proceed to analyze the DTBR scheme using two-dimensional Markov process. Both analysis and simulation results indicate that, by keeping target handoff voice call dropping probability, adoption of elastic data traffic model can reduce handoff voice call dropping probability and improve overall system award; by adjusting the threshold values in the DTBR, we demonstrate that it is capable of satisfying different QoS requirements for voice and data traffic while achieving the maximum utility.

One of the key issues in the next generation wireless cellular networks is to support multiple services, in which call admission control policy has to guarantee the different Quality of Service (QoS) requirement from diverse applications, and at the same time ensure the scarce bandwidth be utilized efficiently. In this paper, we first build upon our proposed Dual Threshold Bandwidth Reservation (DTBR) scheme to integrate more realistic, variable data traffic, and then proceed to analyze the DTBR scheme using two-dimensional Markov process. Both analysis and simulation results indicate that, by keeping target handoff voice call dropping probability, adoption of elastic data traffic model can reduce handoff voice call dropping probability and improve overall system award; by adjusting the threshold values in the DTBR, we demonstrate that it is capable of satisfying different QoS requirements for voice and data traffic while achieving the maximum utility.

We have recently witnessed a phenomenal growth in the development and deployment of wireless services, evident from the proliferation of the cellular data services and the emerging wireless multimedia applications. This opens up a new avenue for research, and calls for the re-examination of some of the fundamental issues in wireless cellular networks. With the cell size being systematically reduced into micro-cell and pico-cell systems, in order to increase the overall network capacity, one of the key challenges is the design of effective call admission control (CAC) policies, which have to guarantee potentially different quality of service (QoS) requirements from diverse traffic types while at the same time maintaining high utilization of the scarce wireless bandwidth. The objectives of this article are to review the key issues involved in the design of call admission control policies based on some of the recent proposals, and to discuss the challenges associated to offer effective support for multi-services.

We have recently witnessed a phenomenal growth in the development and deployment of wireless services, evident from the proliferation of the cellular data services and the emerging wireless multimedia applications. This opens up a new avenue for research, and calls for the re-examination of some of the fundamental issues in wireless cellular networks. With the cell size being systematically reduced into micro-cell and pico-cell systems, in order to increase the overall network capacity, one of the key challenges is the design of effective call admission control (CAC) policies, which have to guarantee potentially different quality of service (QoS) requirements from diverse traffic types while at the same time maintaining high utilization of the scarce wireless bandwidth. The objectives of this article are to review the key issues involved in the design of call admission control policies based on some of the recent proposals, and to discuss the challenges associated to offer effective support for multi-services.

Parallel Simulation techniques have been proposed as a possible solution to execution time and memory constraints often found in detailed simulations of Wireless Cellular Networks. However, partitioning represents a major challenge for models that encompass elements of radio propagation phenomena. This paper discusses the partitionings problem with respect to Parallel Discrete Event Simulation and we formulate an approach to study partitioning of a WCN model that includes radio propagation. Various options for a model of moderate size and where interference is calculated over the whole system are evaluated through experimentation and some limited mathematical analysis. Results indicate that radio spectrum based partitioning is preferable to geographically based partitionings for this model in many realistic scenarios. It is also noted that characteristics of the model differ sufficiently from other previously studied spatially explicit problems to reduce or even annihilate the effectiveness of some commonly used partitioning techniques., QC 20100525

In this paper, a new adaptive admission control scheme for wireless cellular network supporting mixed narrowband and wideband traffic is proposed. The scheme is event-based and provides hard constraints on hand-off dropping probability requirements. The role of the quality of service (QoS) regulation parameter P-ov in the call admission process is analyzed acid presented. The analytic results are validated by simulation. We also show that the analytic model is extensible to more than two types of traffic. (C) 1999 Elsevier Science B.V. All rights reserved.

In this paper, a new adaptive admission control scheme for wireless cellular network supporting mixed narrowband and wideband traffic is proposed. The scheme is event-based and provides hard constraints on hand-off dropping probability requirements. The role of the quality of service (QoS) regulation parameter P-ov in the call admission process is analyzed acid presented. The analytic results are validated by simulation. We also show that the analytic model is extensible to more than two types of traffic. (C) 1999 Elsevier Science B.V. All rights reserved.

In this paper, a new adaptive admission control scheme for wireless cellular network supporting mixed narrowband and wideband traffic is proposed. The scheme is event-based and provides hard constraints on hand-off dropping probability requirements. The role of the quality of service (QoS) regulation parameter P-ov in the call admission process is analyzed acid presented. The analytic results are validated by simulation. We also show that the analytic model is extensible to more than two types of traffic. (C) 1999 Elsevier Science B.V. All rights reserved.