Changyan Yi

Priority-aware pricing-based capacity sharing scheme for beyond-wireless body area networks

In this paper, a radio resource allocation scheme for wireless body area networks (WBANs) is proposed. Unlike existing works in the literature, we focus on the communications in beyond-WBANs, and study the transmission scheduling under a scenario that there are a large number of gateways associating with one base station of medical centers. Motivated by the distinctions and requirements of beyond-WBAN communications, we introduce a priority-aware pricing-based capacity sharing scheme by taking into account the quality of service (QoS) requirements for different gateways. In the designed scheme, each gateway is intelligent to select transmission priorities and data rates according to its signal importance, and is charged by a price with regard to its transmission request. The capacity allocation is proceeded with guarantee of the absolute priority rule. In order to maximize the individual utility, gateways will compete with each other by choosing the optimal transmission strategies. Such decision process is formulated as a non-atomic game. Theoretical analyses show that our proposed pricing-based scheme can lead to an efficient Wardrop equilibrium. Through numerical results, we examine the convergence of strategy decisions, and demonstrate the effectiveness of our proposed mechanism in improving the utilities of gateways.

Spectrum Auction for Differential Secondary Wireless Service Provisioning With Time-Dependent Valuation Information

In this paper, we propose a spectrum auction mechanism for secondary spectrum access in cognitive radio networks. Different from existing works in the literature, the time-dependent buyer valuation information is employed in the proposed mechanism so that the primary spectrum owner (PO) can determine more favorable spectrum allocations and pricing functions in order to maximize the expected auction revenue. In addition, to exploit the temporal spectrum reusability, the proposed mechanism allows each secondary wireless user to declare its specific time preferences, including service starting time, delay tolerance, and service length. By further considering the heterogeneities in secondary wireless service provisioning, the proposed mechanism is able to support heterogeneous forms (continuous or disjointed spectrum usages) of secondary spectrum requests. Specifically, at the beginning of the auction frame, secondary wireless users report their different spectrum usage requests along with the bidding prices, while the PO decides a single-step spectrum allocation and calculates the payment for each winner based on not only the received bids but also the known time-dependent valuation information. Theoretical analyses and simulation results show that the proposed auction mechanism can satisfy all desired economic properties, and can improve the spectrum allocation efficiency and auction revenue compared with counterparts.

OPNET-based Modeling and Simulation of Mobile Zigbee Sensor Networks

Modeling and simulation can help to validate and evaluate the performance of wireless sensor networks (WSNs) within specific applications. In order to resolve the issue of the restriction on node mobility in existing Zigbee WSN simulation models, this paper proposes a Zigbee compliant new simulation model using the OPNET simulator. Based on the Zigbee MAC layer model in OPNET Modeler, we develop a network layer model and propose an improved AODV routing algorithm to support node mobility, both of which are compatible with Zigbee protocols. We further present in details the structure of the network layer process model and the implementation procedures of its kernel functions. Comprehensive performance comparisons are performed between the proposed model and the Zigbee model in OPNET standard libraries. In order to evaluate the effectiveness of the proposed model in the aspect of node mobility support, time intervals between route failure occurrence and route recovery are measured as well. The experimental results show that the proposed simulation model achieves better performance, compared to the original one. In addition, when node mobility causes routing failures, alternative routes can be established quickly by the proposed model.

A Priority-Aware Truthful Mechanism for Supporting Multi-Class Delay-Sensitive Medical Packet Transmissions in E-Health Networks

In this paper, the design of priority-aware truthful mechanisms for multi-class delay-sensitive medical packet transmissions in electronic health (e-health) networks is studied. Unlike most of existing works, we focus on beyond wireless body area network (beyond-WBAN) communications, and consider the absolutely prioritized transmission scheduling as the realization of medical-grade quality of service, i.e., more critical medical packets have to always be transmitted prior to the ones with less emergency. In our model, medical packets arrive randomly at each WBAN-gateway (which ordinarily stands for one patient), and their beyond-WBAN transmission requests are reported to the network regulator (i.e., the base station) with different packet priorities which reflect their medical importance. The base station then dynamically manages the beyond-WBAN transmission service by formulating a multi-class multi-server priority queueing system. Taking into account the potential strategic behaviors from smart gateways, we design a truthful mechanism which can guarantee that all gateways will honestly report the actual priorities of their medical packets, while at the same time incentivize the base station to provide channel usages for e-health services. Theoretical analyses and simulation results examine the desired properties of our proposed mechanism, and demonstrate its feasibility and superiority compared to counterparts.

An Incentive Mechanism Integrating Joint Power, Channel and Link Management for Social-Aware D2D Content Sharing and Proactive Caching

In this paper, a downlink cellular traffic offloading framework with social-aware device-to-device (D2D) content sharing and proactive caching is studied. In the considered system model, each user equipment (UE) is intelligent to determine which content(s) to request/cache and to share according to its own preference. As the central controller, the base station (BS) can establish cellular transmissions and/or incentivize D2D communications for content dissemination (including proactive caching). By taking into account wireless features, social characteristics, and device intelligence, we formulate a welfare maximization problem integrating power control, channel allocation, link scheduling, and reward design. To solve this complicated problem, we propose a novel mechanism which consists of a newly developed optimization approach, called basis transformation method, for the joint resource management, and a specially devised pricing scheme for the reward determination. Theoretical and simulation results examine the desired properties of our proposed mechanism, and demonstrate its superiority in improving social welfare, network capacity, and utility of the BS.

A Sequential Posted Price Mechanism for D2D Content Sharing Communications

In this paper, the incentive mechanism design issue for device-to-device (D2D) content-sharing communications is discussed. In literature, most of works are based on auction/game theory, where all content owners first report their ask prices/costs towards the base station (BS) which finally decides only one winner from them to transmit data towards the content requester. One disadvantage of these works is that content owners may be frequently activated to provide auction/game information (such as prices/costs), leading to high energy consumption, but finally may not win to gain benefit. To address this, we propose a sequential posted price mechanism where the BS sends offers with posted prices to content owners in sequence and activates only one owner each time. The BS stops sending new offers as long as there is already an owner accepting an offer or when the BS finds the expected cost of sending a new offer is larger than the cost of direct transmission. The optimal posted prices and offer- stopping rule of the BS are derived by the backward principle of dynamic programming. Simulation results show that the proposed mechanism can effectively limit the proportion of content owners being activated while the BS maintains an acceptable expected cost.

A Truthful Mechanism for Prioritized Medical Packet Transmissions in Beyond-WBANs

In this paper, the design of a truthful mechanism for prioritized medical packet transmissions in e-health networks is studied. Unlike most of existing works, we focus on beyond wireless body area networks (beyond-WBANs), and consider the absolutely prioritized scheduling, i.e., emergent medical signals have to always be transmitted prior to normal ones. In our model, medical packets arrive randomly at each WBAN-gateway, and their transmission requests are reported to the base station (BS) with different packet priorities. The BS then dynamically manages the beyond-WBAN transmission service by following the proposed mechanism constructed on a multi-class multi-server queueing system. Theoretical and simulation results demonstrate that the proposed mechanism can guarantee all gateways to truthfully report their packet priorities, and can incentivize the BS to provide exclusive channel usages for e-health services.