Open Topics

Vol. 65, n° 5-6, May-June 2010
Content available on Springerlink

How much do we gain by introducing route optimization in Proxy Mobile IPv6 networks?

Jong-Hyouk Lee · Tai-Myoung Chung

Internet Management Technology Laboratory, Sungkyunkwan University, Suwon, Gyeonggi-do, South Korea

Abstract Proxy Mobile IPv6 has been developed from the concept of network-based mobility support protocol in the Internet Engineering Task Force. The recently published specification of Proxy Mobile IPv6 only focuses on the mobility support without a mobile host’s participation in the mobility signaling. Then, route optimization issues are left in the basket for further works. In this paper, we explore the existing route optimization proposals that are analyzed and matched against a list of functional and operational angles. Then, the chosen two route optimization proposals are evaluated in terms of signaling cost, packet delivery cost, total cost, and service blocking probability. Through the provided analysis results, we demonstrate that route optimization solves the ineffective routing path problem when the mobile host communicates with its corresponding host and argue that the scalability of Proxy Mobile IPv6 architecture is also improved due to the distributed routing path. In addition, the cost model developed in this paper would be a reference model in order to facilitate decision making for further route optimization design.

Keywords RO · PMIPv6 · NETLMM · Cost analysis

EFT: a high throughput routing metric for IEEE 802.11s wireless mesh networks

Md. Shariful Islam* · Muhammad Mahbub Alam* · Md. Abdul Hamid** · Choong Seon Hong* · Sungwon Lee*

*Department of Computer Engineering, Kyung Hee University, 1 Seocheon, Giheung, Yongin, Gyeonggi 449-701, Korea
**Department of Information and Communications Engineering, Hankuk University of Foreign Studies, 89 Wangsan-ri, Mohyun-myon, Cheoin-Gu, Yongin-si, Kyonggi-do 449-791, Korea

Abstract In this paper, we present a throughputmaximizing routing metric, referred to as expected forwarding time (EFT), for IEEE 802.11s-based wireless mesh networks. Our study reveals that most of the existing routing metrics select the paths with minimum aggregate transmission time of a packet. However, we show by analyses that, due to the shared nature of the wireless medium, other factors, such as transmission time of the contending nodes and their densities and loads, also affect the performance of routing metrics. We therefore first identify the factors that hinder the forwarding time of a packet. Furthermore, we add a new dimension to our metric by introducing traffic priority into our routing metric design, which, to the best of our knowledge, is completely unaddressed by existing studies.We also show how EFT can be incorporated into the hybrid wireless mesh protocol (HWMP), the path selection protocol used in the IEEE 802.11s draft standard. Finally, we study the performance of EFT through simulations under different network scenarios. Simulation results show that EFT outperforms other routing metrics in terms of average network throughput, end-to-end delay, and packet loss rate.

Keywords Wireless mesh networks · Routing metric · Medium access time · Hybrid wireless mesh protocol · 802.11s

Access network survivability: an architecture approach for monitoring, protection and restoration in FTTH application

Aswir Premadi*,**  Boon Chuan Ng* & Mohammad Syuhaimi* Ab-Rahman* Kasmiran Jumari*

* Spectrum Technology Research Centre, Department of Electrical, Electronics, and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
**Department of Electrical Engineering, Institut Teknologi Padang,Jl. Gajah Mada, Padang 25143, Indonesia

Abstract This paper presented a simple monitoring, protection switching, and fast restoration approach for fiber to the home passive optical network (FTTH-PON) using Access Control System (ACS). ACS is developed for centralized monitoring and failure detection from central office (CO) in downstream direction (from CO towards customer sides). The proposed system architecture incorporating low cost and enable the network service providers and field engineers to remotely control the testing module from anywhere in the world and automatically identify any fiber fault and address the failure location in the fiber field. Another unique function of ACS is to provide the activation for optical switching in a restoration scheme which implemented at the drop region of FTTH-PON. A protection device named Customer Protection Device that comprises of programmable optical switches will be employed at the customer sides, just before the optical network unit, for rerouting the disrupted signals to the protection line when failure occurs in the working line to ensure continuous service delivery to customers.

Keywords ACS . Centralized monitoring . Optical switching . CPD . Protection

An EAP-EHash authentication method adapted to resource constrained terminals

Omar Cheikhrouhou*  Maryline Laurent** Amin Ben Abdallah**  Maher Ben Jemaa*

* Ecole Nationale d’Ingénieurs de Sfax, Unité de recherche ReDCAD, BP W 3038, Sfax, Tunisia
**Institut Télécom, Télécom SudParis, CNRS Samovar UMR 5157-9 rue Charles Fourier, 91011 Evry, France

Abstract In the era of mobile and wireless networks, the growing complexity of end devices and the accentuated tendency towards miniaturization of them raise new security challenges. Authentication is a crucial concern in resource constrained environments, and despite the great number of existing EAP methods, as explained in the article, we are still in need for EAP methods tightly adapted to wireless environments and satisfying heterogeneity of terminals and their limitations of resources. After a first comparative analysis of existing EAP methods, this article presents a new EAP-EHash method (EHash for encrypted hash) that is adapted to the highly vulnerable wireless environment by supporting mutual authentication and session key derivation and offering simplicity, rapidity, and easy-to-deploy features. This EAPEHash was formally proven to satisfy the claimed security properties, thanks to the AVISPA tool. Implementation of it on an 802.11 testbed platformgave realistic authentication delays averaging 26 ms and thus proved that EAP-EHash is competitive to EAP-MD5 that is known to be the simplest of the EAP methods. Features of EAP-EHash include short execution delays and low bandwidth consumption, and as such, it appears attractive for wireless.

Keywords EAP. EAP methods . EAP-MD5 . EAP-TLS . EAP-EHash . Authentication protocol .Validation

On unequal error protection for LZSS compressed data

Richard Demo Souza* · Marcelo Eduardo Pellenz** · Zaqueu Cabral Pereira*

* CPGEI, UTFPR. Av. Sete de Setembro, 3165, Curitiba, Paraná, 80230-901, Brazil
**PPGIA, PUCP-PR. Rua Imaculada Conceição, 1155, Curitiba, Paraná, 80215-901, Brazil

Abstract An unequal error protection scheme for Lempel–Ziv–Storer–Szymanski (LZSS) compressed data is proposed. The novel method divides the compressed data into short blocks, which allows for near-real-time operation. The error protection is obtained through the application of BCH codes and block interleavers. Compared to other methods found in the literature, the proposed scheme is either more efficiency in terms of compression efficient or in terms of decoding delay.

Keywords Data compression · Error correcting codes · LZSS · Lempel–Ziv · BCH codes

Performance enhancement of SC-FDMA systems using a companding technique

Fathi E. Abd El-Samie,  Faisal S. Al-kamali, Moawad I. Dessouky,  Bassiuny M. Sallam, Farid Shawki

Department of Electronics and Electrical Communications, Faculty of Electronic Engineering, Menoufia University, Menouf 32952, Egypt

Abstract In this paper, a companding technique is proposed to effectively reduce the peak-to-average power ratio (PAPR) in single-carrier frequency division multiple access (SC-FDMA) systems. By companding the samples with large amplitudes, while enhancing those with small amplitudes, a significant reduction in the PAPR can be achieved. The performance of the proposed SC-FDMA with companding system is studied and compared with that of the standard SC-FDMA system. Simulation results show that the SC-FDMA with companding system has a lower PAPR when compared with the conventional SC-FDMA system, while the complexity of the system slightly increases. Results also reveal that the companding coefficient must be chosen carefully in order to limit the PAPR without introducing degradations into the bit error rate performance.

Keywords SC-FDMA . Companding . Pulse shaping . PAPR

Survey of NLOS identification and error mitigation problems in UWB-based positioning algorithms for dense environments

Jasurbek Khodjaev*  Yongwan Park*   Aamir Saeed Malik**

* School of Electrical Engineering and Computer Science, Yeungnam University, Gyeongsan, South Korea
** Department of Electrical & Electronic Engineering,Universiti Teknologi Petronas (UTP), Tronoh, Perak, Malaysia

Abstract In this survey, the currently available ultrawideband- based non-line-of-sight (NLOS) identification and error mitigation methods are presented. They are classified into several categories and their comparison is presented in two tables: one each for NLOS identification and error mitigation. NLOS identification methods are classified based on range estimates, channel statistics, and the actual maps of the building and environment. NLOS error mitigation methods are categorized based on direct path and statistics-based detection.

Keywords NLOS . LBS .UWB positioning methods

On the achievable rate region of the Gaussian interference channel: the two- and three-user cases

Patrick Tortelier · Abdoulaye Bagayoko

Orange Labs, 38-40 Rue du General Leclerc, 92794 Issy-les-Moulineaux Cedex 9, France

Abstract This paper addresses the problem of computing the achievable rates for two and three users sharing the same frequency band without coordination and interfering with each other. It is primarily related to the field of cognitive radio studies as we look for the achievable increase in the spectrum use efficiency. It is also strongly related to the longstanding problem of the achievable rate region of a Gaussian interference channel (GIC) because of the assumption of no user coordination and the underlying assumption that all signals and interferences are Gaussian. We give a geometrical description of the signal to interferenceplus- noise ratio region for the two-user and threeuser channels. This geometric approach provides a simple closed-form expression of the achievable rate region of the two-user interference channel and an insight of known optimal power allocation scheme. A closed-form expression of the contour lines of the achievable rate region is also given for the three-user channel.

Keywords Achievable rate region · Gaussian interference channel · Cognitive radio studies

On the cooperative MIMO communication for energy-efficient cluster-to-cluster transmission at wireless sensor network

Mohammad Rakibul Islam · Jinsang Kim

Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon, Kihung, Yongin, Gyeonggi, 449-701, Korea

Abstract Energy-efficient data transmission is one of the key factors for energy-efficient wireless sensor networks (WSN). Cooperative multiple input multiple output (MIMO) explores the wireless communication schemes between multiple sensors emphasizing the MIMO structure. In this paper, an energy-efficient cooperative technique is proposed for a WSN where selected numbers of sensors at the transmitting end are used to form a MIMO structure wirelessly connected with a selected number of sensors at the receiving end. The selection of nodes in the transmitting end is based on a selection function, which is a combination of channel condition, residual energy, inter-sensor distance in a cluster, and geographical location, whereas the selection in the receiving side is performed on the basis of channel condition. Data are sent by the sensors in a cluster to a data-gathering node (DGN) using a multihop transmission. We are concentrating our design on the intermediate hop, where sensors in a cluster transmit their data to the sensors in another cluster with MIMO communication. Energy models are evaluated for both correlated and uncorrelated scenarios. The delay model of the proposed cooperative MIMO is also derived. Experimental results show that the selected MIMO structure outperforms the unselected MIMO in terms of total energy consumption. They also show energy-efficient performance by around 20% over unselected MIMO when they are compared with single-input-single-output structure. Also, the proposed approach takes around 50 more rounds than the geographically selected approach before dying at distance d > 20 m.

Keywords Cooperative technique · Correlation coefficient · Selective approach · MIMO · Wireless sensor networks