IEE Proceedings - Communications
Print ISSN
1350-2425
Online ISSN 1359-7019
Online ISSN 1359-7019
Published from 1994-2006, IEE Proceedings - Communications covered fundamental and generic research for a better understanding of communication technologies to harness signals for better-performing communication systems using various wired and/or wireless media. The journal contained research papers reporting novel solutions to the dominating problems of noise, interference, timing and errors, for the reduction of systems deficiencies, such as wasting scarce spectra, energy and bandwidth resources.
This publication was previously known as IEE Proceedings I (Communications, Speech and Vision) 1989-1993. ISSN 0956-3776. more..
This publication is continued by IET Communications 2007-. ISSN 1751-8628. more..
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Latest content
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Localised credit based QoS routing
- Author(s): S.H. Alabbad; M.E. Woodward
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p.
787
–796
(10)
Localised quality of service (QoS) routing has recently been proposed as a viable alternative approach to traditional QoS routing algorithms that use global state information. In this approach, problems associated with maintaining global state information are avoided by having the source nodes to infer the network QoS state based on flow blocking statistics collected locally, and perform flow routing using this localised view of the network QoS state. A credit based routing algorithm (CBR) which is a simple yet effective localised QoS routing algorithm is introduced. Its performance is compared against the localised proportional sticky routing (PSR) algorithm using different types of network topologies, QoS requirements and traffic patterns and under a wide range of traffic loads. Extensive simulations show that the algorithm outperforms the PSR scheme while maintaining the same level of adaptivity and stability. Its performance is also compared against the global widest-shortest path algorithm (WSP) and it is shown that CBR gives a comparable performance with better time complexity and very low communication overhead.
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Diversity performance of a dual-linear polarisation suspended gap-coupled microstrip antenna
- Author(s): T.S.P. See; Z.N. Chen
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p.
797
–801
(5)
The diversity performance of a dual-linear polarisation microstrip antenna is investigated across the broad operating bandwidth. As an example, the suspended gap-coupled microstrip antenna has been chosen for the study. Using a ±45° polarisation scheme, the probe-fed square main patch, surrounded by four parasitic patches on its radiating and non-radiating sides, is suspended above the ground plane. The simulated and measured impedance as well as the radiation performance are given. The diversity performance is evaluated in terms of the far-field coupling, output power correlation as well as the diversity gain in a non-fading channel. From the analysis performed at three primary frequencies, the diversity performance has been found to vary across the impedance bandwidth. It is shown that other than the environment, the radiation characteristics of the antenna have a considerable effect on the diversity gain.
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Multiuser MIMO-OFDM systems using subcarrier hopping
- Author(s): M. Jiang; L. Hanzo
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p.
802
–809
(8)
Recently space division multiple access (SDMA) assisted multiple-input–multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems invoking multiuser detection (MUD) techniques have attracted substantial research interest, which is capable of exploiting both transmitter multiplexing gain and receiver diversity gain. A new scheme referred to here as slowsubcarrierhopping (SSCH) assisted multiuser SDMA-OFDM, is proposed. It is shown that, with the aid of the so-called uniform SSCH (USSCH) pattern, the multiuser interference (MUI) experienced by the high-throughput SDMA-OFDM system can be effectively suppressed, resulting in a significant performance improvement. In the investigations conducted, the proposed USSCH-aided SDMA-OFDM system was capable of outperforming a range of SDMA-OFDM systems considered, including the conventional SDMA-OFDM system dispensing with the employment of frequency-hopping techniques. For example, at an Eb/N0 value of 12 dB, the proposed USSCH/SDMA-OFDM system reduced the bit error ratio (BER) by about three orders of magnitude, in comparison to the conventional SDMA-OFDM system, while maintaining a similar computational complexity.
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GPRS/UMTS-aided authentication protocol for wireless LANs
- Author(s): Y.-M. Tseng
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p.
810
–817
(8)
Wireless local area network (WLAN) and cellular network are two important technologies for providing wireless communications. For user authentication of WLAN, the IEEE 802.1X standard provides an authentication framework that is based on the Extensible Authentication Protocol (EAP). When a roaming user wants to access WLANs provided by different operators, the user must remember multiple identities and the corresponding authentication credentials. Obviously, such an exercise is not user friendly. This problem is caused by the fact that a visited WLAN does not have the authentication credential of a roaming user. Previous proposals have studied the authentication of inter-network roaming across different WLANs, or across a cellular network and a WLAN. As is known, cellular networks provide wider service areas, ‘always-on’ and ubiquitous connectivity. The integration of WLAN and cellular networks has a management advantage that it can unify the subscriber identity and the corresponding credential. In this paper, we first propose a practical certificate distribution scheme. The certificate distribution scheme allows roaming users of a cellular network to obtain temporary certificates from their home cellular network. Afterward adopting certificate-based authentication protocol of the IEEE 802.1X standard, roaming users may use temporary certificates to access WLANs. The proposed solution achieves easy subscriber management and pervasive access. As demonstrated, the proposed solution also provides mutual authentication and strong identity protection, in addition to withstanding the man-in-the-middle attack and the eavesdropping attack. A performance evaluation shows that the proposed protocol is well suited for roaming users with mobile devices.
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Reducing the peak-to-average power ratio using turbo coding
- Author(s): M. Al-Akaidi; O. Daoud
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p.
818
–821
(4)
Owing to the susceptibility to the peak-to-average power ratio (PAPR) on orthogonal frequency division multiplexing (OFDM) systems, the authors introduce a novel approach based on turbo coding to improve OFDM (PAPR) performance. In the paper, it is shown that even for different types of modulation methods and coding rates, the technique is still applicable and gives better performance comparing to the conventional techniques being used (such as the clipping technique and the partial transmit sequence (PTS) technique).
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Pairwise key establishments without key pre-distribution for mobile ad hoc network environment
- Author(s): G. Wang; G. Cho
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p.
822
–827
(6)
Because all data packets are transmitted via an unreliable medium in ad hoc networks, it is indispensable to establish a secure pairwise key between any two nodes in the networks. In the key pre-distribution based schemes, because the same pre-distributed keys are spread over a number of nodes in the network, even a small number of compromised nodes can threaten the security of the network. On the other hand, other schemes using a pre-shared key among all nodes are only suitable for static networks and cannot be applied to the mobile network environment. In the proposed scheme, each node establishes some keys with nodes that are at most three hops away at network configuration time. Later, when any two nodes establish a pairwise key between them, all nodes on the route between them contribute to the establishment by sending their own secret keys to both nodes. Here, the pre-established keys are employed to encrypt the secret keys sent from the nodes on the route. The simulation results show that the proposed scheme is better than the key pre-distribution based scheme in terms of the number of exchanged messages, the success frequency of key establishment, and the robustness against compromise of nodes.
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Using an agent based platform to map quality of service to experience in conventional and active networks
- Author(s): M. Siller; J. Woods
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p.
828
–840
(13)
A quality of experience (QoE) metric is defined as being the user's perception of the network's QoS parameters. The QoE defines a combination of user satisfaction, understanding and interest. Using agents, network QoS parameters are controlled in an attempt to match the user's perceived QoE. The QoS is managed through an arbitrator using (a) a series of rules and reference tables and (b) the end-user feedback. Within the framework presented the user can change the QoS requirements at any time. It is believed that by empowering the user to select the quality according to expectation, QoE can be improved relative to the individual. A mapping to the perceived QoE is derived from a group of objective and subjective weighting factors associated to the QoS performance parameters. The framework has been validated by building a prototype. A series of experiments was conducted in which both a conventional and an active QoS mechanism was employed by the arbitrator. The QoE mapping has proved useful for understanding the relation between objective and subjective metrics in the experiments. From these measurements the QoE requirements and a general outlook of the network and the conditions at the time of the transmission may be inferred.
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Performance analysis of channel aware frequency hopping
- Author(s): M. Elkashlan; C. Leung; R. Schober
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p.
841
–845
(5)
An efficient method is presented to evaluate the performance of a channel-aware multiple-access scheme based on slow frequency hopping (CAFH) with r rounds. In contrast to conventional FH, which uses a channel state independent hopping sequence, the transmitter in the channel aware scheme hops to the available frequency subband which currently has the largest transmission gain. It is shown that this scheme can offer significant performance improvements over conventional FH at the cost of a more complex transmitter structure. The resulting closed-form expressions are used to investigate the effect of the number, r, of rounds on the error probability for a cellular communication system. Numerical examples are presented to illustrate the application of the new analysis.
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Multiservice provisioning mechanism with service curves assurance for per-class scheduling delay guarantees
- Author(s): C.-K. Siew; M.-H. Er
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p.
846
–855
(10)
Class-based traffic treatment frameworks, such as differentiated service (DiffServ), have been proposed to solve the scalability problem of flow-based approach for quality of service (QoS) provisioning. While these frameworks provide service differentiation according to traffic classes, the provision of QoS guarantee for individual flows, within a class, remains a challenging problem. In the paper, the authors present a novel multiservices mechanism, which is able to provide service curves assurance for per-flow deterministic delay guarantees. The core component of this mechanism is a new packet scheduling algorithm, called flow-state-dependent packet scheduling (FDPS), to handle different flows within the same class to provide end-to-end scheduling delay bound guarantees. The mechanism is based on an analysis that guides the flow admission control operation for class-based queueing delay bound. Using the packets' flow-states, FDPS provides fine granularity packet service differentiation within each class. By means of this property, the proposed mechanism achieves per-flow end-to-end delay bound independent of the number of intermediate nodes along the path of the flow. Another notable feature is that it can be integrated into a DiffServ framework as an enhancement for deterministic QoS guarantees. The performance of this mechanism is mathematically analysed to demonstrate its enhancements and ns-2 simulation experiments are used to validate the analytical results.
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Optimum design of Cayley differential unitary space-time codes based on union bound
- Author(s): J. Wang; X. Wang
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p.
856
–864
(9)
The Cayley differential (CD) codes constitute a systematic way to construct differential unitary space-time codes for noncoherent MIMO communications. The present authors propose designing CD codes by minimising the union bound based on the exact pairwise error probability (PEP). The gradient descent method is employed to numerically search the optimum dispersion matrices. They search the optimum CD codes for a particular scenario taking into account the number of transmit and receive antennas and the operating SNR. Simulation results show that codes optimised by the new criterion generally outperform the CD codes designed by maximising the expected distance between codeword pairs and the Cayley TAST codes that satisfy the full rank criterion. The new CD codes also enjoy better or comparable performance over other group-based or non-group codes.
