Spectrum management for wireless networks using adaptive control and game theory

This paper proposes a joint adaptive rate selection and power control algorithm for broadband TDMA/TDM wireless networks. The proposed algorithm is a modified, enhanced, and more robust version of the selective power control with active link protection (SPC-ALP) algorithm proposed for adaptive transmission rate and power control in CDMA networks [R.Jantti and S. Kim, 2000]. Unlike SPC-ALP, the proposed algorithm uses adaptive coding and modulation (instead of variable spreading gain) for transmission rate control. In addition, the proposed algorithm is different in two aspects; the first one is the inclusion of the cochannel interferer assistance mode, while the second one is the use of the signal quality as a criterion for user removal. Results show that the proposed algorithm outperforms SPC-ALP in terms of the net throughput and signal quality measures such as the outage probability and frame error rate. Channel reallocation is also studied and found to be very effective in enhancing the system performance particularly at low to medium loading.

In ad hoc networks of nodes equipped with multiple antennas, the tradeoff between spatial multiplexing and diversity gains in each link impacts the overall network capacity. An optimal algorithm is developed for adaptive rate and power control for a communication link over multiple channels in a Poi

Large-scale Internet of Things (IoT) deployments require long-range wireless communication, particularly in urban and metropolitan environments. Long-Range Wide-Area Network (LoRaWAN), based on LoRa technology, emerges as a promising solution due to its simplicity, flexibility, and low power consumption. However, deploying LoRa networks in dense IoT scenarios presents challenges, such as ensuring efficient communication among numerous devices and maintaining resilience against dynamic channel conditions. This work evaluates Adaptive Data Rate (ADR) and power control mechanisms to optimize LoRa communication parameters using FLoRa, an open-source framework for end-to-end LoRa simulations in OMNeT++. To this end, this paper proposes a novel ADR approach, ADR-I-MODE, which estimates the Signal-to-Noise Ratio (SNR) using the most frequent value in recent transmissions. This technique is validated against its floating-point counterpart, ADR-F-MODE, to demonstrate its efficiency. The proposed method enhances packet delivery rates and energy efficiency across varying channel conditions. Additionally, this work proposes a node-level power control technique, ADR-NPC, to improve connectivity in challenging environments. This technique successfully reconnects up to 86% of dropped nodes with a minimal primary power setting of 2 dBm, demonstrating its potential for future integration into LoRa Alliance standards. These findings contribute to the development of more resilient and scalable LoRaWAN deployments for diverse IoT applications.

In this paper we investigate the effect of an adaptive fuzzy closed-loop power control (CLPC) scheme on the performance of the DS/CDMA-based mobile satellite communication systems with a low earth orbit (LEO) satellite constellation in which the long round trip delay (RTD) and fading effect according to elevation angle should be considered. Since the RTD between mobile terminals (MT) and earth station (ES) via satellite in LEO is on the order of 10-20 ns and fading is more severe, a conventional closed-loop power control with fixed step size is much less effective than it is on a terrestrial channel. In order to cope with this performance degradation, we propose a closed-loop power control scheme by adaptive fuzzy rule-based step size decision method which is based on fuzzy logic control (FLC). So, in this paper, we compare the performance of the adaptive fuzzy closed-loop power control with that of the conventional fixed step closed-loop power control, we show that the proposed method makes better performance.

Energy Efficiency is one of the key issues in Low Rate Wireless Personal Area Networks (LR-WPANs). So far, many research papers have been published on the subject of energy efficiency. However, the throughput in LR-WPAN hasn’t been extensively investigated. Therefore, in this paper, we focus on impr

Maximizing network lifetime of unreliable and resource constrained wireless networks such as mobile ad hoc networks involves optimal allocation of power and shared channels in the network. Existing optimal power and channel allocation mechanisms mainly focus on throughput maximization and energy efficiency but fail to obtain a trade-off between delay and energy consumption in the network. This paper proposes a game theoretic energy efficient approach that mimics a fair non-cooperative game among nodes competing for shared channels and power level. Unlike existing power and rate control mechanisms, the proposed energy conserving adaptive power and rate control (ECAPRC) mechanism takes into consideration the constraints of outage probability and total average delay to deal with stochastic changes in the channel that improves the network performance in terms of throughput, delay and total energy consumption. Proposed super-modular game has a unique convergence point called “Nash Equilibrium” and its existence and uniqueness is proved in the paper. To enhance the convergence rate of proposed ECAPRC approach, an adaptive grey wolf optimizer is employed to deal with delay and energy constraints. Simulation results and their analysis show that proposed ECAPRC approach outperforms existing approaches such as dynamic rate and power allocation algorithm, rate-effective network utility maximization and energy conserving power and rate control in terms of above mentioned network parameters and total utility of the system.

Adaptive data rate control in low power wide area networks for long range IoT services

In cellular radio systems, cochannel interference determines frequency reuse distance. To achieve high-capacity systems, cochannel interference reduction is considered a key item. Intrazone channel reassignment (IZCR) and adaptive transmitter power control (ATPC), are effective techniques to reduce cochannel interference. A novel IZCR algorithm is proposed that maximizes the number of channels that satisfy a required carrier-to-interference ratio (CIR). By computer simulations, the interference reduction effects by either IZCR or ATPC and by both ATPC and IZCR are clarified. With the call block rate of 0.03 and the outage probability of 0.01, the CIR margin can be reduced by equal to or more than 10 dB by adopting both ATPC and new IZCR.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

In mobile ad hoc networks, since nodes move around the network, the network topology and the number of neighboring nodes in each node frequently change. Although the number of neighboring nodes in each node and the distance between each node always changes, the transmission range of each node is not changed. Therefore, it is expected that many packet collisions among nodes occur and energy power of each node is much consumed. This paper proposes an adaptive transmission power control scheme for hierarchical routing. In the proposed scheme, each node changes the transmission power according to the number of neighboring nodes of each node in the autonomous clustering. In order to show the effectiveness of the proposed scheme, the performance has been evaluated through the simulation experiments.

The present paper incorporates the impact of adaptive downlink power control in modern satellite communication networks on the broadband wireless access networks. DVB-S2 and WiMax standards specify the employment of adaptive power control as fade mitigation technique at frequencies above 10 GHz. The subject of this paper is to furnish a physical model for the examination of the increased interference due to satellite downlink power control to WiMax terminals. To quantify the interference effects, the carrier-to-interference ratio (CIR) statistics of WiMax link is being calculated. Extended numerical are presented and finally some useful conclusions regarding the spectral coexistence of WiMax and DVB-S2 networks are drawn. (4 pages)

This paper proposes an adaptive P2P rate control scheme to provide fairness between P2P traffic and traditional Internet traffics and throughput improvement. The proposed scheme adjusts P2P traffic volume through the temporary transmission interrupts when network experiences congestion.

Random linear packet coding combined with adaptive power and rate control is being considered as an alternative to traditional ARQ techniques for the underwater acoustic channel. We first analyze a scheme where the number of coded packets to transmit is determined so as to achieve a pre-determined reliability at the receiver, and hence eliminate the need for explicit feedback. We next investigate joint power and rate control with constrained resources. Using the channel gain information which is obtained via feedback from the receiver, the transmitter adjusts its transmit power and the number of coded packets such that the average energy per bit is minimized. We impose two main constraints for the optimization: (a) the transmit power should be within a maximum available power, and (b) the number of coded packets should not exceed a maximum value. Under these constraints, we define adaptation policies to minimize the average energy per bit and show analytical results for average energy savings available from the adaptation policies. We also show experimental results obtained using the measured channel gains from the SPACE-08 experiment, an at-sea experiment conducted off the coast of Martha's Vineyard in Massachusetts.

Adaptive Power and Rate Control for Wireless Networks with Time-Varying Uncertainties

An enhanced adaptive scheme based on threshold method with a reduced complexity that combine adaptive modulation and coding with diversity combining is presented for throughput maximization in broadband code division multiple access (CDMA) satellite networks. The proposed algorithm is a modify, enhanced, and more robust version of the existing algorithms for adaptive transmission rate and modulation in CDMA networks. The rate compatible punctured turbo-coded (RCPT), which has been found to give improved throughput performance in a direct sequence (DS) CDMA is exploited. A semi-analytical process and simulations were carried out. It is found that there are significant improvement in the average throughput and the bit-error performance. The proposed algorithm using adaptive coding and modulation (instead of variable spreading gain) outperforms other systems such as Selective Power Control with Active Link Protection (SPC-ALP) algorithm proposed for adaptive transmission rate and power control in CDMA networks.

In mobile multicast over cellular networks, the wireless fading channels for different multicast receivers are usually heterogeneous, from both instantaneous and statistical perspectives. This feature imposes significant challenges in designing efficient multicast schemes to adapt to the channel variations. We investigate the adaptive rate and power control for multicast over generally distributed broadcast fading channels in cellular networks, with the focus on the two-receiver case. Specifically, we aim at optimizing the minimum achievable average good put over all receivers through time-sharing based rate adaptation under the fixed/variable power strategies. By developing an SNR-plane partition based method, we derive the optimal rate adaptation policy for the constant (fixed) power strategy. Moreover, we obtain the optimal power-rate adaptation policy for the variable power strategy by using the Lagrangian duality theory. Simulation results are also presented to show the performance gain obtained from our derived optimal policies.