Radio resource management games in wireless networks: an approach to bandwidth allocation and admission control for polling service in IEEE 802.16 [Radio Resource Management and Protocol Engineering for IEEE 802.16]

Game theory is a mathematical tool developed to understand competitive situations in which rational decision makers interact to achieve their objectives. Game theory techniques have recently been applied to various engineering design problems in which the action of one component impacts (and perhaps conflicts with) that of any other component. In particular, game theory techniques have been successfully used for protocol design and optimization (e.g., radio resource management, power control) in wireless networks. In this article we present an overview of different game theory formulations. Then a survey on the game-theory-based resource management and admission control schemes in different wireless networks is presented, and several open research issues are outlined. To this end, we propose an adaptive bandwidth allocation and admission control scheme for polling service in an IEEE 802.16-based wireless metropolitan area network. A noncooperative game is formulated, and the solution of this game is determined by the Nash equilibrium for the amount of bandwidth offered to a new connection. The admission control policy ensures QoS for all connections in the system     

Dynamic resource allocation in OFDMA wireless metropolitan area networks [Radio Resource Management and Protocol Engineering for IEEE 802.16]

In this article we present important resource allocation problems in IEEE 802.16 wireless metropolitan area networks employing orthogonal frequency division multiple access. We first highlight the unique aspects of these networks and identify challenges and opportunities provided by the physical and medium access control layers. Next, we concentrate on four interrelated resource allocation problems: dynamic subcarrier allocation, adaptive power allocation, admission control, and capacity planning. We describe solution techniques, provide preliminary results, and discuss open problems for future research     

Radio resource management of heterogeneous services in mobile WiMAX systems [Radio Resource Management and Protocol Engineering for IEEE 802.16]

IEEE 802.16e, known as mobile WiMAX, has gained much attention recently for its capability to support high transmission rates in cellular environments and QoS for different applications. Beyond what the standard can define, in order to effectively support video streaming, VoIP, and data services, proprietary radio resource management, including multiconnection assignment, scheduling controls, and call admission controls, are essential. In this study we evaluate the downlink performance of a mobile WiMAX cellular system with different radio resource management, especially the scheduler for QoS control and the implementation of multiconnection for streaming applications     

On the impact of physical layer awareness on scheduling and resource allocation in broadband multicellular IEEE 802.16 systems [Radio Resource Management and Protocol Engineering for IEEE 802.16]

Multicellular networks based on the IEEE 802.16 standard appear to be very promising candidates to provide end users with broadband wireless access. However, they also pose interesting challenges in terms of radio resource management, where several design choices are not specified in the standard, intentionally left open to implementors. For this reason, we focus in this article on scheduling and resource allocation, and investigate how they could operate in a cross-layer fashion. In particular, we describe the principles of joint scheduling and resource allocation for IEEE 802.16 operating in AMC mode, and discuss the critical role played by physical layer considerations, especially intercell interference estimation and channel state awareness, in the obtained performance. This leads to identifying key open issues and possible general solutions     

A dynamic joint scheduling and call admission control scheme for IEEE 802.16 networks

We propose a dynamic joint scheduling and call admission control (CAC) scheme for service classes defined in IEEE 802.16 standard. Using priority functions, equipped with service weights and service arrival rates, the proposed scheduling scheme differentiates service classes from each other. Based on obtained priority values, we first allocate the achievable bandwidth proportionally. Within individual service classes, we then use appropriate local schedulers to transmit packets accordingly. Moreover, instead of immediate admitting or blocking a new connection request, the proposed CAC scheme computes the average transmission rate that can be allocated to that connection during a time interval. The connection is admitted if its required rate is satisfied while at the same time QoS requirements of ongoing connections are not violated. Our numerical results demonstrate the effectiveness of the proposed schemes compared to the other schemes in the literature.     

Probabilistic call admission control in wireless multiservice networks

A new probabilistic call admission control scheme is proposed for multiservice wireless networks. The new scheme gradually suppresses the admission rate of the new calls and of the calls of each service class (SC) supported considering their priorities independently. The scheme is examined both for a single SC and for multiple SCs under general conditions. The analysis employs Markov chain theory and yields analytical expressions for the call blocking probabilities. The proposed analytical method was validated via simulations employing different distributions for the channel holding time; the simulations demonstrated the accuracy of the proposed framework.     

Adaptive scheduling mechanism for IPTV over WiMAX IEEE 802.16j networks

A WiMAX technology is a very promising Broadband Wireless Access technology that is able to transmit different service types. This latter can have different constraints such as traffic rate, maximum latency, and tolerated jitter. The IEEE 802.16 Medium Access Control specifies five types of QoS classes: UGS, rtPS, ertPS, nrtPS, and BE. However, the IEEE 802.16 standard does not specify the scheduling algorithm to be used. Operators have the choice among many existing scheduling techniques. Also, they can propose their own scheduling algorithms. In this paper, we propose a scheduling strategy (Adaptive Weighted Round Robin, AWRR) for various Internet Protocol Television (IPTV) services traffic over 802.16j networks. Our scheme adapts dynamically the scheduler operation to according queue load and quality of service constraints. In particular, the proposed mechanism gives more priority to high definition television and standard definition television traffic by using two schedulers. The proposed scheduling algorithm has been simulated using the QualNet network simulator. The experimental results show that our scheduler schemes AWRR have a better performance than the traditional scheduling techniques for rtPS traffic, which allows ensuring QoS requirements for IPTV application. Copyright © 2012 John Wiley & Sons, Ltd.     

A call admission control strategy for multiservice wireless cellular packet networks

A simple connection control system for multiservice cellular wireless networks is presented. Mobile stations are classified depending on the traffic they generate (e.g., voice, data). Within each class, two subclasses are also identified: stations which have originated inside the cell and stations which come from adjacent cells. The connection control mechanism is carried out by considering a number of priorities among the various classes and their subclasses. It works on two levels: static and dynamic. The static level looks at packet-level quality of service (QoS), such as cell loss and delay, while the dynamic level takes care of connection dynamics and allows the load of the system to be driven with respect to the various subclasses. Results that illustrate the performance of this control mechanism are presented.     

A probabilistic approach for fair-efficient call admission control in wireless multiservice networks

The efficiency of call admission control (CAC) schemes in multiclass wireless networks should be evaluated not only with regard to the call blocking probability (CBP) achieved for every service class (SC) supported but also with regard to quality of service (QoS) and network efficiency criteria. In this article, four CAC schemes offering priority to SCs of advanced QoS requirements, based on guard channel policy, are studied and evaluated taking into account fairness and throughput criteria in addition to CBP. For the performance evaluation of the proposed CAC schemes and to examine fairness issues, two fairness indices are introduced along with a throughput metric. The analytical results, validated through extensive simulations, indicate that by appropriate selection of the CAC parameters satisfactory fairness and throughput are achieved while achieving low CBP.     

Enabling collocated coexistence in IEEE 802.16 networks via perceived concurrency - [WiMAX update]

Multiple wireless interfaces (GSM, Wi-Fi, Bluetooth, FM, and GPS receiver, etc.) are being integrated into mobile devices. WiMAX, an IEEE802.16-based wireless access technology recently included in the IMT-2000 set of standards by ITU-R, will soon be added. Obstacles remain to operating these collocated radios concurrently, including interference and hardware conflicts due to congested spectrum allocation and component sharing with radio integration. In this article we provide a tutorial overview of today?s solutions to enable concurrent operation of multiple collocated radios in IEEE 802.16- based wireless networks with a focus on perceived concurrency: a MAC coordination approach. We then present three general design principles ? predictability, compressibility, and flexible scheduling ? with examples of standard features. It is anticipated that the next-generation IEEE 802.16 standards will be enhanced with new features such as explicit service setup, asynchronous operation, and collocated coexistence- aware scheduling.     

Adaptive call admission control in 3GPP LTE networks

In this article, we propose new methods to reduce the handoff blocking probability in the 3rd Generation Partnership Project Long Term Evolution wireless networks. This reduction is based on an adaptive call admission control scheme that provides QoS guarantees and gives the priority of handoff call over new call in admission. The performance results of the proposed schemes are compared with other competing methods using simulation analysis. Simulation results show the major impact on the performance of the 3rd Generation Partnership Project Long Term Evolution network, which is reflected in increased resource utilization ratio to (99%) and in the ability in satisfying the requirements of QoS in terms of call blocking probability (less than 0.0628 for Voice over IP service) and dropping probability rate (less than 0.0558).Copyright © 2012 John Wiley & Sons, Ltd.     

Adaptive connection admission control for differentiated services access networks

In our earlier work, we have proposed some modifications for the bandwidth broker framework. With our modifications, it is possible to use measurement-based admission control in addition to the more traditional parameter-based admission control. Moreover, we have presented a new flexible admission control scheme that has proven to be very efficient in terms of bottleneck link utilization. Two problems, however, have arisen: the use of scheduling weights in admission control and bursty connection arrivals. In this paper, we present that the former one can be dealt with the use of adaptive scheduling weights, while the latter one can be fought with adaptive reservation limits. The proposed new algorithms are validated through simulations and their performance is compared against the nonadaptive basic scheme.     

QoS-oriented resource allocation for streaming flows in?IEEE802.16e Mobile WiMAX

Users in OFDMA-based WiMAX are subject to Adaptive Modulation and Coding (AMC) which implies more robust and hence less frequency efficient modulation and coding for users experiencing bad radio conditions. When users are mobile, this implies lower throughput as they move away from the base station for instance. This may be acceptable for data users, but not for streaming ones which require a constant bit rate throughout the cell. We propose, in this work, a new QoS-oriented resource allocation strategy wherein streaming flows experiencing bad radio conditions are allocated more sub-carriers so as to keep their bit rate constant as they move around in the cell. The risk is however an increase in the dropping rate. To minimize the latter without increasing blocking too much, they are second subject to a state-dependent admission control scheme where the degree of acceptance depends on the density of the users in a given location. We develop an analytical model which allows us to derive some performance measures such as blocking and dropping probabilities. Our results quantify how these metrics vary with the load as well as the admission strategies.     

Radio resource management and protocol engineering for IEEE 802.16 [Guest Editorial]

The special section features six articles that focus on radio resource management issues in IEEE 802.16/WiMAX-based broadband wireless systems. This guest editorial discusses the major issues pertaining to the topic and summarizes the articles included in this section.     

Characterization of jitter and admission control in multiservice networks

In statistical admission control based on effective bandwidth, the network provides probabilistic guarantees for the packet loss and delay. In integrated multiservice networks like third-generation mobile networks, some traffic classes also need guarantees on the jitter. One approach is to treat jitter like delay. This letter proposes a new criterion to take into account jitter guarantees. Numerical results show that our criterion is effective and adds improvement up to 10% on the bandwidth management.     

Call admission control scheme with normalized quality of service metric in IEEE 802.16 networks

IEEE 802.16 network introduces a multimedia data scheduling service with different quality of service (QoS) requirements. The scheduling service manages transmission resources according to data types, satisfying the requirements of different connections or users. On the basis of the data types defined in the service, we discuss a normalized QoS metric for the multimedia connections in the paper. The QoS value of a connection can be determined just by three components: the data type of the connection, its desired resources, and its allocated resources. Then, we propose an optimum bandwidth allocation solution, which can maximize the utility of base station. Next, we propose a call admission control scheme utilizing the bandwidth allocation solution. In the scheme, the occupied resource of ongoing connections will be regulated for the entry admission of a new connection, without degrading the network performance and the QoS of ongoing connections. Finally, the simulation results confirm that the proposed scheme with the normalized QoS can achieve better trade‐off between ongoing connections and new connections.Copyright © 2012 John Wiley & Sons, Ltd.     

S-WiMAX: adaptation of IEEE 802.16e for mobile satellite services - [WiMAX update]

Mobile satellite services are attracting renewed attention stemming from the FCC ancillary terrestrial component ruling that allows satellite spectrum to be used for integrated terrestrial services in the footprint of the satellite. This attention is focused on the development of dual-mode satellite-terrestrial devices to facilitate hybrid satellite-terrestrial networks intended by the ATC order. The satellite component in these dual-mode devices is best adapted from the air interface chosen for the ATC to optimize form factor, especially for small hand-held devices, mobility management, power efficiency, and a common core network functionality. With the advent of WiMAX as a viable 4G technology, satellite adaptation of WiMAX has been considered for the satellite services coupled with WiMAX ATC. The main considerations for satellite adaptation of WiMAX, relative to its terrestrial counterpart, are reduced link margin and longer transmission delays ? both absolute delay from the center of a spot beam to the satellite and differential delay between the beam edge and the beam center to the satellite. These considerations suggest adaptation of the subchannelization schemes, the frame synchronization methods, and the ranging process in WiMAX to make it operable over satellite, while keeping the general framework of the WiMAX protocol stack intact, thereby facilitating the incorporation of S-WiMAX into a common baseband processor with terrestrial WiMAX; this allows S-WiMAX to be added to terrestrial WiMAX devices with minimal cost and formfactor impact. Methods for these adaptations are considered here.     

Queue-aware uplink bandwidth allocation and rate control for polling service in IEEE 802.16 broadband wireless networks

IEEE 802.16 standard defines the air interface specifications for broadband access in wireless metropolitan area networks. Although the medium access control signaling has been well-defined in the IEEE 802.16 specifications, resource management and scheduling, which are crucial components to guarantee quality of service performances, still remain as open issues. In this paper, we propose adaptive queue-aware uplink bandwidth allocation and rate control mechanisms in a subscriber station for polling service in IEEE 802.16 broadband wireless networks. While the bandwidth allocation mechanism adaptively allocates bandwidth for polling service in the presence of higher priority unsolicited grant service, the rate control mechanism dynamically limits the transmission rate for the connections under polling service. Both of these schemes exploit the queue status information to guarantee the desired quality of service (QoS) performance for polling service. We present a queuing analytical framework to analyze the proposed resource management model from which various performance measures for polling service in both steady and transient states can be obtained. We also analyze the performance of best-effort service in the presence of unsolicited grant service and polling service. The proposed analytical model would be useful for performance evaluation and engineering of radio resource management alternatives in a subscriber station so that the desired quality of service performances for polling service can be achieved. Analytical results are validated by simulations and typical numerical results are presented.     

Cross-layer Based Delay-constraint Adaptive Polling for High Density Subscribers in IEEE 802.16 WiMAX Networks

The IEEE 802.16 standard (namely WiMAX) is proposed to support QoS-aware transmission of real-time service in Wireless Metropolitan Area Networks (WMANs). WiMAX also can operate as a wireless backbone, and then cooperates with WiFi to form a heterogeneous wireless network. Thus, hot spots of WiFi belonging to different WiMAX networks can communicate with each other. For achieving that a Base Station (BS) serves a large number of Subscriber Stations (SSs), WiMAX uses a centralized polling access mechanism instead of a random access mechanism. WiMAX thus avoids occurring access collisions but causes long polling delay under a high-density SSs situation. Consequently, IEEE 802.16 does not schedule real-time service (rtPS) while the BS is in multicast polling mode. This problem of long polling delay becomes worse when the BS serves high-density SSs, because the BS only polls some SSs or groups in every frame time. This paper thus proposes an adaptive polling approach with a cross-layer mechanism, which dynamically polls SSs among different polling modes while continuously supporting the rtPS service. The approach consists of two phases. The first phase adopts two hysteresises of number of SSs and residual bandwidth to determine the optimal polling mode for each connection. The second phase presents a novel QoS-aware rtPS service (QrtPS) that provides an Average Delay requirement instead of the Maximum Delay requirement to take over the rtPS service when a SS is polled by the multicast mode. Additionally, a cross-layer mechanism is proposed to achieve that the real-time applications can be sent with a high-quality or low-quality video codec when the SS is in unicast or multicast mode, respectively. Numerical results demonstrate that the proposed approach significantly outperforms IEEE 802.16 in average delay and network utilization. Furthermore, the collision probabilities of using different numbers of contention slots of an uplink subframe and different numbers of groups within a BS are evaluated for the multicast mode. The results meet the experiments.

Bandwidth allocation and call admission control in high-speednetworks

The authors discuss the broad issue of bandwidth allocation and call admission control (CAC) in high-speed networks, focusing on asynchronous transfer mode technology. It is maintained that despite the considerable amount of high-quality work carried out in this area, the debate surrounding these issues is not yet resolved. The complexity of dealing with a wide variety of as yet unknown user traffic types, as well as the evolving architecture of networks, means that currently proposed solutions are only an intermediate step of the design process. The authors discuss the nature of user traffic and illustrate how it can impact the debate on the quality of service, concentrating on some “equivalent bandwidth” type CAC strategies. Also discussed is a method which uses diffusion approximations. Finally, the authors discuss the novel issue of evaluating the overload created by the CAC procedure itself on network nodes. The article is complemented by several numerical and simulation results which illustrate the discussion