Femtocell Devices Research Articles

A serious gaming approach to managing interference in ad hoc femtocell wireless networks

The aim of this paper is to optimize femtocell performance by managing interference between femtocell devices and between a femtocell and a macrocell. It achieves this using a three-phase approach that involves deployment of femtocells and control of resulting connections through consideration and management of path loss, transmission power, signal strength and coverage area. Simulation experiments of the proposed three-phase approach at a local college that experiences a poor service from the macrocell predict significant improvements in femtocell performance in terms of managing both types of interference: co-tier and cross-tier, number of users who experience good service, coverage, and mitigating outage probability. The overall and individual complexity of each phase has also been considered. Our approach has been compared with some existing techniques chosen from the literature that has been reviewed and its predicted performance is significantly improved in comparison to these.

PMIPv6 Integrated with MIH for Flow Mobility Management: A Real Testbed with Simultaneous Multi-Access in Heterogeneous Mobile Networks

The exponential growth of the number of multihomed mobile devices is changing the way how we can connect to the Internet. Our mobile devices are demanding for more network resources, in terms of traffic volume and QoS requirements. Unfortunately, it is very hard to a multihomed device to be simultaneously connected to the network through multiple links. The current work enhances the network access of multihomed devices agnostically to the deployed access technologies. This enhancement is achieved by using simultaneously all of the mobile devices interfaces, and by routing each individual data flow through the most convenient access technology. The proposed solution is only deployed at the network side and it extends Proxy Mobile IPv6 with flow mobility in a completely transparent way to mobile nodes. In fact, it gives particular attention to the handover mechanisms, by improving the detection and attachment of nodes in the network, with the inclusion of the IEEE 802.21 standard in the solution. This provides the necessary implementation and integration details to extend a network topology with femtocell devices. Each femtocell is equipped with various network interfaces supporting a diverse set of access technologies. There is also a decision entity that manages individually each data flow according to its QoS / QoE requisites. The proposed solution has been developed and extensively tested with a real prototype. Evaluation results evidence that the overhead for using the solution is negligible as compared to the offered advantages such as: the support of flow mobility, the fulfil of VoIP functional requisites, the session continuity in spite of flows mobility, its low overhead, its high scalability, and the complete transparency of the proposed solution to the user terminals.

펨토셀 주파수 신호 생성을 위한 IEEE 1588 기반 클록 동기화 시스템의 설계

This article presents a circuit and a system for IEEE 1588 based clock synchronization to generate a very accurate frequency signal required in femtocell devices. A prototype board and the experimental environment to verify the functions and to evaluate the performance are explained to verify the feasibility of the proposed synchronization system. To make low-cost femtocells without constraints on the place of installation, it is very important to study on the practical implementation of synchronization system based on IEEE 1588. The experimental result shows that the synchronization errors between -16 ns and 9 ns are guaranteed over the network of femtocell devices with the proposed synchronization circuits, thus the synchronization criteria of the 3GPP HNB are met.

Cracking cellular networks via femtocells

Recent revelations about the security weaknesses of femtocell devices are just the latest in a long history of cellular network security vulnerabilities. Cellular network companies (cellcos) have made considerable efforts to impose security on their infrastructure, which is seen as being of national importance, but is extending this infrastructure into the home creating a weak spot? Recent revelations about the security weaknesses of femtocell devices are just the latest in a long history of cellular network security vulnerabilities. Cellular network companies (cellcos) have made considerable efforts to impose security on their infrastructure, but is extending this infrastructure into the home creating a weak spot? Security researchers claim to have found that femtocells constitute vulnerability by providing a path through to key points in cellular networks – specifically those maintained by Vodafone, although the company disputes this. Steve Gold investigates the controversy.

Packet Scheduling and Traffic Differentiation in Femtocell Environment

This paper proposes new scheduling algorithms for best effort (BE) traffic classification in business femtocell networks. The purpose of traffic classification is to provide differentiated services to BE users depending on their traffic classes, and the concept of traffic classification is called Inter User Best Effort (IUBE) in CDMA2000 1x Evolution Data Optimized (EVDO) standard. Traffic differentiation is achieved by introducing Grade of Service (GoS) as a quality of service (QoS) parameter into the scheduler's decision metric (DM). New scheduling algorithms are called QoS Round Robin (QoS-RR), QoS Proportionally Fair (QoS-PF), QoS maximum data rate control (DRC) (QoS-maxDRC), QoS average DRC (QoS-aveDRC), QoS exponent DRC (QoS-expDRC), QoS maxDRC-PF (QoS-maxDRC-PF). Two different femtocell throughput experiments are performed using real femtocell devices in order to collect real DRC values. The first experiment examines 4, 8, 12 and 16 IUBE users, while second experiment examines 4 IUBE + 2 Voice over IP (VoIP), 8 IUBE + 2 VoIP, 12 IUBE + 2 VoIP, 16 IUBE + 2 (VoIP) users. Average sector throughput, IUBE traffic differentiation, VoIP delay bound error values are investigated to compare the performance of the proposed scheduling algorithms. In conclusion, QoS-maxDRC-PF scheduler is proposed for business femtocell environment.

Standardization of femtocells in 3GPP2

Driven by the need for multivendor interoperability of femtocell devices and their supporting infrastructure equipment, the cdma2000reg standards community has been undertaking a large-scale and comprehensive effort to develop industry standards for femtocell devices and systems based on the cdma2000 family of radio access technologies. This article describes those standardization activities and provides an overview of the femtocell system architecture that has been developed within 3GPP2.

Standardization of femtocells in 3GPP

Cellular system operators have identified the critical need for standardization of femtocell devices and their associated interfaces into the operators' core networks as a critical requirement for the success of femtocell products. Driven by this demand, the UMTS/UTRAN standards community has been undertaking a large-scale and comprehensive effort to specify such standards for femtocell devices and systems that are based on the UMTS/HSDPA/HSUPA family of radio access technologies. This article describes those standardization activities and provides an overview for the femtocell system architecture that has been developed within 3GPP.