New Publications are available for Mobile radio systems
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Please follow the links to view the publication.Evolution of communication based train control worldwide
http://dl-live.theiet.org/content/conferences/10.1049/ic.2012.0054
The paper summarises the evolution of rail signalling system from track-circuit signalling to advanced Communication-Based Train Control (CBTC) systems, highlighting the differences, benefits and challenges with regard to improving performance while ensuring safety. It describes the evolution of such systems over the last three decades; from wayside signals to cab signals, to profile-based systems, to communications-based train control systems for an effective means of overcoming the fundamental limitations of the conventional track-circuit based system. CBTC allows trains to operate with much closer headways while ensuring safe train separation and better train control flexibility. Not only do CBTC systems determine the position of the train with a higher degree of accuracy independently of the track circuits, but also offer bidirectional train/wayside communication to enhance train operations and supervision. Operational and performance benefits realised with the newer technology systems are discussed, together with the challenges of implementing such systems. Standardisation for Communication Based Signalling System initiatives is also described and industry trends presented.Telecommunications supporting signalling and railway operations
http://dl-live.theiet.org/content/conferences/10.1049/ic.2012.0049
This paper seeks to set out how telecommunications supports signalling systems and the operational railway. The paper also considers telecommunication developments occurring on the railway and what this will provide for signalling. For ease, this paper has been divided into two broad sections: the railway communications network which provides the core on which specific applications, and others depend, and then the railway specific applications of telecoms technology that support the operational railway.Signalling the future
http://dl-live.theiet.org/content/conferences/10.1049/ic.2012.0039
This paper provides an overview firstly of the development of railway signalling systems, which has been a combination of engineering inventiveness coupled with reactive engineering after accidents and incidents. It then moves on to explore the technological opportunities and necessities facing railway control systems engineers. It explores too the quest for improved performance, and the need to focus not just on safety, but to contribute to the delivery of a cost-effective, efficient and environmentally friendly railway as well. Finally, the author briefly considers the skills and expertise we will need to deliver the systems of the future.The role of organic compounds in simulation of dust environments for electric contacts
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0620
Organic compounds were shown to exist on the failed electric contacts of printed circuit boards in mobile phones. The compounds adhered to both dust particles and wear debris and caused contact failure under dynamic conditions. As one of the organic compounds found on the contaminated electric contacts in failed mobile phones, sodium lactate was chosen for investigation. The physical characteristics of sodium lactate were measured so that the adhesive function of sodium lactate with dust particles could be estimated theoretically and proven by vibration experiments. The hygroscopic and evaporative performance of the sodium lactate was tested, and the relationship between the hygroscopic performance and the insulation resistance was also discussed. The electrical behavior of the dust contaminated contacts with the organics was studied by sliding tests. The experimental results could lead to a method for applying organics in the simulation of dust environments for electric contacts.Remote monitoring of power transformers thermal image
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0730
This paper presents an original technical solution of device for distributive transformers' thermal image recording. The paper elaborates mathematical model of power transformer's thermal image, applied to estimate its hot-spot temperature. The block-scheme and brief technical description of realized device are presented here. The paper presents both hardware and firmware solution of the system. Developed prototype of such device has been tested during several months, in real conditions, in one substation 10/0.4 kV/kV in serbian capital, Belgrade. Permanent transmission of measured data have been obtained via GPRS. Technical solution of remote monitoring is described in the paper, too. (4 pages)Design concepts for a wideband HF ALE capability
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0379
The recently promulgated US military standard MIL-STD-188-110C contains an appendix (Appendix D) defining a new family of wideband HF data waveforms supporting bandwidths from 3 kHz to 24 kHz in increments of 3 kHz. This family of waveforms extends the high performance serial tone modem technology of the MIL-STD-188-110B standard to wider bandwidths and much higher data rates, allowing users the option of selecting the bandwidth and modulation so as to optimize modem performance under the prevailing HF channel characteristics. However, fully realizing the potential of these new waveforms will require enhanced capabilities in other elements of an HF communications system, notably including a new `Fourth Generation' (`4G') Automatic Link Establishment (ALE) capability. This paper discusses requirements and design objectives for such a 4G-ALE technique, sketches some candidate 4G-ALE design concepts, and reports early results from on-air testing aimed at verifying the suitability and feasibility of these design concepts. (5 pages)A channel assignment algorithm for cognitive radio wireless sensor networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0583
Cognitive Radio (CR) is a promising technology for improving spectrum utilization in wireless computer networks. Cognitive radio has the ability to sense the spectrum, decide the vacant bands and use of these available bands in an opportunistic approach. Cognitive Radios can be used in both licensed and unlicensed bands. In this case, the licensed wireless users (Primary Users) are a priority for using allocated band. Cognitive radio users (Secondary Users) are allowed to access the channel, if they do not cause interference in the performance of PU. So, Channel management is an important factor on system performance. In cognitive radio sensor network (CRSN), a wireless sensor network (SU) has been merged with a primary system such as mobile network as a cognitive scheme. Because of power constraints in wireless sensor network (WSN), channel management algorithms should be designed for decreasing power consumption. In this paper, a novel channel assignment algorithm for cognitive radio sensor network is proposed and its performance on two power consuming functions include spectrum handoff and users collision is explored. (4 pages)Application of LTE to wireless sensor systems
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0603
Wireless sensors may be connected directly to a cellular network. The power consumption and cost of these cellular devices need to be minimised. Sensors typically create small infrequent datagrams. A 3GPP Long Term Evolution (LTE) network needs to communicate many signalling messages in order to transfer these datagrams. This paper presents some novel techniques to reduce the power consumption and cost of LTE devices and to reduce the signalling associated with supporting sensor systems over an LTE network. (5 pages)Security infrastructure in open wireless sensor and cellular mobility architectures
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0596
An integrated security mechanism is one of the significant challenges in the open wireless network infrastructure because of the diversity of the wireless networks in OMI (Open Mobility Infrastructures) and the unique security mechanism used in each one of these networks. The overall security of the network is as strong as its weakest component and the integration of the overall security mechanism in OMI is of primary importance. In this article, we comparatively analyze the unique network-centric features and security mechanisms of various heterogeneous wireless networks that are expected to be part of OMI concepts and then propose a unique integrated security infrastructure. (5 pages)Results from field tests of STANAG 4538
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0368
The Swedish Armed Forces use HF manpack radios to communicate between vehicles and base stations in international missions, such as ISAF in Afghanistan and the EU Nordic Battle Group 2011. During 2011 a major upgrade of the whole information system was planned including replacing the old 2G-ALE radios with the 3G-ALE based Harris RF-5800H manpack radio system. A number of enhancements to the 3G-ALE standard and to the IP handling have been added by Harris - and reported in [1], [2] and [3] - making the radio ideally suited in this type of missions. As part of that replacement a number of field trials were conducted in Sweden to verify that the radio system will be able to forward the requested traffic, which mainly consist of position reporting (Friendly Force Tracking) and secure voice communication. In order to increase the message transfer reliability, meaning the percentage of position reports received from a vehicle on the move, various means of antenna arrangements and types, frequency use, transmission schemes and diversity techniques were analyzed and tested. The paper presents the results from these field tests as reported in [4], [5] and [6]. (7 pages)Three-dimensional route prediction algorithm based on minimal available information in wireless ad hoc sensor networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0604
In this paper we propose a three dimensional algorithm for the optimum route prediction based on minimal available information, as we have no information from node position, velocity and velocity change also transmission power. The algorithm holds capabilities to finds a proactive route prediction in wireless sensor networks and predicts link lifetime capable to capturing the remaining time for which a link can be used for efficiently routing, therefore intended to be used for optimized route construction with consideration to predict longest living link lifetime between two nodes, without adaptation of specific mobility model. We present an adaptive route prediction algorithm that accurately predicts the longest living link between nodes in wireless sensor network, as algorithm gets input from a periodically sampled data that gathered in a noisy range of two nodes of a link. (5 pages)Modelling 2G and 3G ALE: a quantitative comparison
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0369
Differences in behaviour between 2G and 3G (Fast Link Setup or FLSU) ALE linking protocols are analysed using a common Discrete Event Simulation (DES) architecture designed to focus on the impact on overall HF network performance due to differences in the ALE linking protocols rather than differences due to their waveforms. This was achieved by setting the statistical likelihood of linking to be the same within the 2G and 3G network simulations - equating to real world scenarios where the propagating channels have SINADs of typically 10dB or more. Under these assumptions the simulation results show that the default 2G ALE linking approach performs poorly in mesh or `tactical' style networks in comparison to 3G, but that there is no significant advantage to using 3G over 2G for `hub and spoke' style networks. (5 pages)Integration for EMC and Network Rail's management process
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0191
This paper provides an overview of the management process being developed in Network Rail in the framework of current safety legislation for the UK railways, which accounts for the new regulations for Electromagnetic Compatibility (EMC) in place in UK from 20 July 2007.Railway communication systems
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0185
Communication Systems are essential for the safe and efficient operation of the London Underground (LU) railway, in all operating modes. This paper provides an introduction to Railway communications including the essential principles and applications used in the LU environment. Current technological developments and future strategies are discussed at the end of the paper.PIFA with improved characteristic for wireless communication
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0060
In this paper, a Planar Inverter F antenna with improved characteristics has been presented. Planar Inverted F Antenna (PIFA) is used for wireless communication mainly in mobile communication. The PIFA generally have low efficiency, gain and bandwidth when mounted on normal conductive ground plane but when it is placed on defective ground structure (periodically spaced holes on ground plane), it mitigates its defect by reducing the spurious radiation. The EBG substrate enhances the characteristics of PIFA in terms of gain and efficiency due to suppression of surface waves that are being generated in case of normal conductive ground plane.Real time car theft decline system using ARM processor
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0059
Due to the insecure environment the ratio of vehicle theft increases rapidly. Because of this is manufacturers of luxury automobiles has the responsibilities for taking steps to ensure the authorization for the owners and also inbuilt the anti theft system to prevent the car from theft. The existing system was. Car alarm techniques are used to prevent the car theft with the help of different type of sensors like pressure, tilt and shock & door sensors.Drawbacks are cost and cant used to find out the thief, it just prevents the vehicles from loss. The proposed security system for smart cars used to prevent them from loss or theft using Advanced RISC Machine (ARM) processor. It performs the real time user authentication (driver, who starts the car engine) using face recognition, using the Principle Component Analysis - Linear Discreminant Analysis (PCA LDA) algorithm. According to the comparison result (authentic or not), ARM processor triggers certain actions. If the result is not authentic means ARM produces the signal to block the car access (i.e. Produce the interrupt signal to car engine to stop its action) and inform the car owner about the unauthorized access via Multimedia Message Services (MMS) with the help of GSM modem. Also it can be extends to send the current location of the vehicle using the GPS modem as a Short Message Services (SMS) as passive method.The potential of Internet of Things (IOT) for assisted living applications
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0040
Presents a collection of slides covering the following topics: m-IOT; healthcare IT; medicine; mobile healthcare; Long Term Evolution; 4G health; m-health; Internet of things; RFID; protocol; WSN; AAL systems; diabetes management system; cellular phone; assisted living; wireless medical sensors; ulPv6 and 6LoWPAN. (40 pages)Assessing task compliance following reminders
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0026
People suffering from early stage dementia still have the capability to perform instrumental activities of daily living (iADL) such as the preparation of meals, if reminded to do so. The features available in everyday technology such as mobile phones have been exploited to support increased independence of the people with dementia and to provide lower carer burden. The mobile phone-based video streaming reminder system (MPVS) delivers video reminders via a mobile which have previously been recorded by the carer. To date it was not possible to ascertain if the reminded task was actually performed or not. This work presents a case study which aims to assess task compliance of a reminder system within a 'sensorised environment. (5 pages)Agent based bandwidth estimation in heterogeneous wireless networks
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0093
Next generation mobiles in 4G wireless network have provision to access the radio resource of heterogeneous wireless networks. Further the ongoing call can be switched to another wireless network on occurrence of congestion or mobility. This technique of transferring ongoing call to another wireless network defined as vertical handoff. Before initiating vertical handoff it is necessary to estimate the available bandwidth in heterogeneous neighbouring networks. This paper addresses the agent based bandwidth estimation in 4G wireless networks. The agents together find an optimal available bandwidth for connectionless and connection oriented service. The model uses both the static and mobile intelligent agent.Internet of M-health Things 'm-IOT'
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0036
Internet of Things (IoT) is a new and evolving concept that provides connectivity to the Internet via sensing devices to achieve intelligent identification and management in a heterogeneous connectivity environment. From the assisted living perspective, this emerging concept will enable new communication connectivity routes between elderly disabled patient and care services through innovative networking architectures in AAL environments. M-health is defined as "mobile computing, medical sensor, and communications technologies for health care" [1]. This evolutionary concept provides both mobility and 'always connected' functionalities for different healthcare applications. In this paper we introduce a new amalgamated concept of Internet of m-health Things (m-IoT). m-IoT is a new concept that matches the functionalities of m-health and IoT for a new and innovative future (4G health) applications. In principle m-IoT introduce a new healthcare connectivity paradigm that interconnects IP-based communication technologies such as 6LoWPAN with emerging 4G networks for future Internet based healthcare services. In this paper we will present a general m-IoT architecture based on 6LoWPAN technology for measurement of body temperature as an example for healthcare application. (3 pages)Detecting malicious beacon nodes for secure localization in distributed wireless networks
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0081
Secure distance-based localization in the presence of cheating beacon (anchor) nodes is an important problem in mobile wireless adhoc and sensor networks. Despite significant research efforts in this direction, some fundamental questions still remain unaddressed. When the number of cheating beacon nodes is greater than or equal to a given threshold, no two-dimensional distance-based localization algorithms exist that can guarantee a bounded error. In this paper, the problem of robust distance-based localization in the presence of malicious beacon nodes will assume theoretically that the number of malicious beacon nodes are below threshold and derive a necessary and sufficient condition for having a bounded localization error and use heuristic algorithm that can achieve a bounded error. Suppose if the number of cheating beacons is equal or more than the threshold will use the suspicious message detection by signal strength for detecting and eliminating malicious beacon nodes. The primary goal here is to conduct a thorough analytical study of the distance-based localization problem in the presence of cheating beacons. Finally, it shows that the heuristic-based algorithm provides good localization precision with a very small tune cost.Black hole attack and their counter measure based on trust management in MANET: A survey
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0087
Mobile ad-hoc network (MANET) is an autonomous system connected by mobile nodes with wireless links. Due to absence of infrastructure, MANET is used in various applications, such as battlefield, business applications, and remote areas. As, communication among the nodes is through the insecure wireless link, security is very important issue for this type of networks. MANET is vulnerable to attacks such as Black hole attack, Gray hole attack, wormhole attack, Sybil attack, and Route table modification attack. Black hole attack has serious impact on routing and delivery ratio of packets. To overcome Black hole attack, a mechanisms such as trust based routing, intrusion detection system, sequence number comparison and Data Routing Information table (DRI) has been proposed. Trust based On Demand routing mechanism identifies and decreases the hazards by malicious node in the path. This paper provides a survey of preventing and identifying Black hole attack using trust management mechanism in MANET.Multicast routing in MANET using multiple reliable rings backbone
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0051
In this paper, we propose Multicast Routing scheme in MANET using Multiple relaible Rings backbone (MRMR) that constructs the boundary of MANET with the help of a convex hull algorithm. Multiple rings are constructed at an appropriate distance between the centroid of convex hull and the boundary. Mesh of multicast routes are established by a path that comprises of following segments: a source and its nearest ring node, sources nearest ring node to destination's nearest ring node and destination's nearest ring node to destination. Multicast routes are set up to recover routes against link failures, node failures and mobility patterns with local patch-up of failed links. MRMR outprforms in terms of control overheads, packet delivery ratio and packet delivery latency as compared to an adaptive backbone (ADB) based multicast routing for MANETs.Topology scalability and routing in homogeneous and heterogeneous access networks
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0061
The growth in the different technologies has made us to think of integrating them, for more flexibility, efficiency, user convenient usage and still more to list. Technologies are evolving towards broadband information access across multiple networking platforms in order to provide continuous connection of multimedia services and applications. In such technologies the heterogeneous networks access (4G wireless communication) is one of them. In heterogeneous networks the radio resource management plays an important role to utilize the resource. The homogeneous and heterogeneous network has their own issues to resolve to adopt the different needs of the people. In our scheme we considered the both of them and tried resolve the resource allocation and power management issues. The scheme provides resource allocation for dynamic cellular network and keeping the LAN network static. The dynamism is considered with respect to incoming and outgoing nodes in the cellular network. The power level comparison of the nodes in the cellular networks is done to allocate the resource and accept the call.Preemptive AOMDV routing for mobile Ad-hoc networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0436
An Ad hoc network will often change rapidly in topology, this courses for routes in the network to often disappear and new to arise. The Ad-hoc On-Demand Distance Vector Routing Protocol(AODV), is based on the principle of discover routes as needed. The Ad Hoc On Demand Distance Vector (AODV) routing protocol performs better than the table-driven protocol. Link failure caused by node mobility is a common feature of multi-hop, wireless ad hoc networks. With a reactive routing protocol such as AODV (Ad hoc On-demand Distance Vector), this leads to increased delay and routing overheads while route repair procedures are carried out. In this paper we will extend the definition of A OD V with the ability to discover multiple routes to a host and switch between them, if an active route is be coming weak and there is a risk that it will disappear. We will refer to it as "pre-emptive AOMDV". We will show that the performance of pre-emptive AOMDV do handle changes in topology better than AODV it self. To show the effect of extending AODV, the suggested protocol is implemented in a simulator. Performance enhancements will be presented from different scenarios, to compare pre-emptive AOMDV with the ordinary AODV.A design of indoor & outdoor navigation system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0795
In view of the fact that people need the precise outdoor navigation and indoor navigation, as well as universal information and real-time information, this paper proposes a high resolution navigation system and a handheld navigator for indoor & outdoor environment. For indoor environment, where GPS cannot be applied, the designed handheld terminal achieves precise positioning and navigation through its own sensors and indoor identification utilities. Additionally, the system provides users with information navigation service, which can realize geographical information navigation and real-time information navigation in indoor areas and outdoor areas through handheld terminal.A new indoor mobile node tracking scheme based on RSSI and Kalman filter
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0878
In this paper, a novel scheme to track moving node in indoor wireless sensor network is proposed. Firstly, the observed position is estimated by a moving node position algorithm based on Received Signal Strength Indication (RSSI). Secondly, a Kalman filter is used to estimate position in order to improve position accuracy. Simulation results show the effectiveness of presented algorithm in indoor environments.Exploratory analysis of urban mobility: from mobile phone usage data to tourist behaviour
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0310
In this paper, we propose to use tools of exploratory spatial analysis to study the mobility of foreign visitors in a city like Paris. Using digital traces from mobile phones, we explore several aspects of mobility: how people move from one place to another, but also how these places are linked together. The exploration depends on a methodology which uses visualizations to reveal patterns in large heterogeneous data-sets.. This allowed us to gain new insights on how to analyze noisy and imprecise spatio-temporal data, and to formulate a reliable hypothetical model of tourist urban mobility. (6 pages)Call admission control for long term evolution
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0928
In this paper, the threshold behavior in Call Admission Control (CAC) is investigated. Two multi-threshold CAC schemes, namely the dual threshold bandwidth reservation and the Tri-threshold bandwidth reservation scheme, are studied. Based on the findings, the novel concept of adaptive threshold for CAC is further investigated. It is concluded that the adaptive CAC scheme can be applied to Long Term Evolution.Investigation on a NLOS error mitigation algorithm for TDOA mobile location
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0787
In typical Urban environment, non-Line-Sight (NLOS) propagation between the base station (BS) and mobile station (MS) became the main factor of the positioning error. As a result, the study on the mitigation of its negative influence becomes a focus. Base on Chan algorithm, this paper presents a TDOA mobile location algorithm, which can improve the positioning accuracy effectively. The positioning process includes NLOS error identification and its mitigation. First, the Wylie algorithm is used to identify the existence of NLOS. And then, the time of arrival (TOA) is update based on the difference of TOA and the distance between BS and MS. This coordinate of the MS is estimated by using Chan algorithm in the process of this distance calculating. Simulation results show that this algorithm can mitigate the NLOS error and improve the location accuracy in different environment effectually.An FPGA-based MIMO-OFDM with golden decoding
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0908
With the development of communication technology, the rising interest in wireless communication for providing mobile as well as nomadic and fixed services for video, voice and data, a new system of MIMO-OFDM is designed for providing best-in-class performance attributes such as latency, capacity, peak and sustained data rates and corresponding spectral efficiencies, overall network complexity and quality-of service management. In this paper, we present a prototype FPGA design for an available Golden decoding implementation of a MIMO-OFDM technique. Some necessary concepts of MIMO-OFDM system which are involved in the Golden decoding are introduced. The module of Golden decoding is integrated and synthesized on Xilinx, Virtex5-XC5VSX95T FPGA. The simulation and debugging tool of Modelsim is used to verify the functionality of the Golden decoding module, the simulator analysis of ChipScope and the graph of constellation of 16QAM demapping are used to analyze the captured data.Performance analysis of superposition coding for mixed unicast and broadcast transmission using opportunistic multicast scheduling scheme in LTE-A system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0658
A scheme transmitting superposition coding (SC), which superimposes unicast data to multicast data, using opportunistic multicast scheduling (OMS) scheme, is proposed and its performance is evaluated and simulated in this paper. Although the scheme is a little weaker than traditional scheme using QPSK modulation method in bit error rate (BER) performance, its throughput and system time delay promote considerably. Numerical results show that when user channel condition is weak and signal to noise ratio (SNR) is not high, the new scheme can outperform the conventional scheme in terms of system performances.LTE and future evolutions for the benefits of security wireless networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0927
First responders make use of professional wireless system (e.g. TETRA) for conducting their missions. Those systems are today mainly used to convey voice and short messages. To improve the operational effectiveness, these organisations need wireless data transmission capabilities to exchange images, access to databases or transmit live video streams from the incident area. But, these needs cannot be realised with narrow-band technologies. However, LTE can bring these capabilities to first responders with timely exchange of files and transmission of live high definition video streams. Besides, future enhancements of LTE, LTE-Advanced, will further improve the performance not only to the benefits of mobile operators but also for first responders by providing additional coverage flexibility and more capacity especially at the cell edge, two key performance indicators of a radio security network.A new technology of short-range communication for 'one card solution' in school
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0760
This article proposes a short-range communication between SD card in mobile phone and reader. This technology, called RF-SD, combine the RFID module and SD card to achieve exchanging data with readers. The article also suggests some application of this technology based on "one card solution" in school.An adaptive method utilizing channel reciprocity in TDD-LTE system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0799
In a time-division-duplex (TDD) system the channel state information (CSI) can be obtained at the transmitter side due to channel reciprocity and it can be used to increase the spectral efficiency of a multiple-input multiple-output (MIMO) system. However, the frame architecture, system parameters, pilot architecture, the moving speed of UE and the interference structure affect the channel reciprocity. The transmission parameters assigned based on the reverse link measurements may lead to excessively high frame error rates, if the channel reciprocity doesn't exist or interference structure between transmission directions differs significantly. In this paper, an adaptive method of TDD-LTE system is studied. This method analyzes the above factors to propose a criterion of judging the channel reciprocity, compensates asymmetric interference, and then utilize balance of channel reciprocity and feedback. Analysis and simulation results show the proposed scheme can compensate the asymmetric interference, make using the channel reciprocity possible, reduce the feedback load and demonstrate better system performance.Real-time speech coding and decoding for GSM system and its implement in VC
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0789
Speech signal is the most important part of the GSM mobile communication, thus the speech coding technology and high efficiency digital modulation technology can provide a higher system capacity for digital mobile networks than analog mobile network. Most of the implementation of speech code-decode is mainly in DSP platform, but this paper presents three low- rate speech coding schemes provided in the 3GPP protocol and the way to implement them in VC platform. We describe a compressed method to greatly reduce the size of the coded audio files. In addition, we can play decoded audio files in VC++ in real-time. It is impossible to play audio files in the DSP platform. So our method in VC platform is better than the method in DSP platform.An improved algorithm of synchronization based on maximum correlation for GSM signals
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0691
Several traditional algorithms of synchronization of GSM signal first discussed in this paper. They do not work well at low signal-noise-ratio. An improved algorithm based on maximum correlation is proposed in this paper. This paper compares and analyses the proposed algorithm with the traditional algorithm. Finally, a simulation has been taken to show the performance of different algorithm. The simulation shows that the proposed algorithm can conquer the strong interfere and synchronize accurately.The bit error rate performance of MPSK over extended Rayleigh fading channel
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0873
In this paper, the symbol error rate performances of MPSK over extended slow Rayleigh fading channel are studied. Closed expression for MPSK signalling over non-frequency slow fading channels is derived. Since the classical Rayleigh fading channel is a special case of the extended Rayleigh fading channel where the inphase and quadrature components of the corresponding complex-valued Gaussian noise process are statistically independent, the derived expression can be verified by comparison with the results for the classical Rayleigh fading channel. The presented results are useful in studying the performance of digital modulation signals transmission over mobile fading channels.Adaptive transmission mode selection in LTE-A carrier aggregation scenarios
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0675
Carrier aggregation is one of the most distinct features of 4G systems including LTE-A (Long Term Evolution Advanced), which is being standardized in 3GPP as part of LTE Release 10. The closed-loop concept with codebook based precoding MIMO (multiple-input multiple-output) and transmission mode selection, termed as RI (rank indicator) selection, have been deployed in LTE-A systems to provide high system performance required by 4G systems. This article focuses on the study of adaptive transmission mode selection in LTE-A carrier aggregation scenarios. We propose an adaptive transmission mode selection scheme using average channel capacity and BER to maximize the average spectral efficiency (ASE) with a given target bit error ratio (BER). Numerical results demonstrate improvement over each fixed modern terms of average spectral efficiency.Research on competitive advantage mechanism of the mobile internet ecosystem
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0710
The industry convergence of mobile networks and the Internet produces the mobile Internet. The form of mobile Internet competition has changed, which is no longer a competition between individual enterprises, but a competition between the business ecosystems. This paper builds the competitive advantage model of mobile Internet ecosystem based on the user needs. Then we, using this model, analyze the three major mobile Internet ecosystems: terminal operators, service providers and network operators. We also believe that value innovation is the specific means to achieve system competitive advantage. At last we build a set of evaluation index system of system competitive advantage, and evaluate the three major ecosystems.Doppler diversity technique based on pilot-aided channel estimation for OFDM wireless mobile communication
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0717
In the previous works on the traditional Doppler diversity algorithms, it is always assumed that the channel state information is perfect known at the receiver. However, this is not the case in real world. Hence, a novel Doppler diversity technique based on pilot-aided channel estimation for OFDM systems is studied in this paper. The performance of the proposed algorithm decreases if the value of normalized frequency shift is fixed as that in the traditional algorithm. But for the changeable value of normalized frequency shift, the performance is increased. Hence a method how to choose the optimum normalized Frequency shift based on pilot-aided channel estimation is researched in this paper. Finally, the simulation is evaluated to verify the analysis results.Enhanced mobility state detection based mobility optimization for femto cells in LTE and LTE-advanced networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0687
In 3GPP LTE and LTE-Advanced networks, femto cells will be deployed to improve indoor coverage and increase system capacity. Mobility management (MM) for femto cells is challenging due to their huge number, small size and random deployment. This paper investigates the mobility state detection mechanism, which is crucial for the MM. It is observed that the conventional mobility state detection mechanism is not suitable for femto cells due to the lacking of cell type information. And the inaccurate mobility state detection may lead to improper mobility parameter scaling and then cause handover performance degradation. To solve this issue, Enhanced Mobility State Detection (EMSD) mechanism is proposed. In EMSD, cell type information is considered and more accurate mobility state can be detected for feinto cells. Performance evaluation results show that the EMSD can reduce ping-pong handovers without increasing RLF probability significantly.Coexistence study on tetra and LTE system around 806MHz
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0702
The conversion from analog TV to digital TV improves the spectrum efficiency and makes the 698-806MHz available for IMT system in the future. In China, 806MHz-821MHz has been allocated to the uplink of digital trunking system. If IMT system is deployed in 698-806MHz in the future, the IMT system and trunking system will coexist adjacently around 806MHz. This paper focuses on mutual interference between IMT system and the uplink of trunking system around 806MHz. Deterministic analysis and system simulation is adopted in the coexistence study. The result of study provides scientific foundation and technical support for spectrum plan in 698-806MHz.Optimal distributed estimation in mobile ad hoc sensor networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1462
Consider a set of mobile wireless sensors that are embedded in devices that might, for example, be carried by pedestrians or vehicles that move about a city. A subset of these sensors may observe a localized event that occurs when they are all at approximately the same time/location. As they continue to move, the first one to take action based on its observations assumes the role of a Cluster-Head (CH) and floods the ad-hoc network with a request that all other sensors that collected observations of that event send in estimates related to some aspect of it.A BLUE estimator is used to fuse the individual estimates received by the CH. To ensure that these local estimates are unbiased, even if they are based on noisy observations and are relayed over multiple noisy wireless channels, we employ dithered quantization and channel compensation. We then determine the optimal number of bits for each sensor to transmit to minimize the energy the network uses to produce a BLUE with a specified MSE. The motion of each sensor determines how many hops its transmitted data traverses to reach the CH and thus how many bits it should transmit to the CH. We model this motion in the 1D case as a Correlated Random Walk (CRW). This allows us to precisely determine transient behavior, even with geographical restrictions and preferred directions of motion. We can then determine the energy, as a function of time, required to collect the estimates from all relevant sensors for the MSE of the final estimate to achieve a threshold. We demonstrate the capability of this approach by determining the minimum energy required to produce the estimate from a set of sensors that starts walking at one traffic light, spreads out in space, and then gathers together at the next traffic light.Ergodic and outage capacity for Ricean fading channel with shadow fading on high-speed railway
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1016
In this paper, we discuss the channel characteristics on high-speed railway and discuss the ergodic and outage capacity for Ricean channel with shadow fading. The impacts of dynamic K factor on ergodic and outage capacity are evaluated too. Simulation results show both shadow fading and dynamic K factor have significant impact on outage capacity, but little impact on ergodic capacity.Cellular phone data analysis in comprehensive transportation survey: a case study in Beijing
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1399
In the fourth Beijing comprehensive transportation survey, cellular phone data was used for person trip characteristics analysis. In this paper, traditional person trip survey and literature are reviewed firstly. It is worth mentioning that actual cellular phone data is used in this research rather than artificial data is in other literatures. Then, cellular phone location positioning technology is introduced. Person trip features are implicated in the massive location positioning data with timestamp. The method of data analysis is described in details. The procedure architecture is divided into four layers, which are data layer, model layer, system processing layer and application layer. Finally, resident distribution and hourly population density expansion results in Beijing based on cellular phone data analysis are shown and discussed. It is concluded that the analysis results are generally consistent with the historical statistics. In particular, the resident movement characteristics can be captured easily by the hourly population density expansion analysis. The method put forward in this research is reasonable and feasible, which provides a new tool for person trip characteristics survey of urban transportation planning.Distributed PMIPv6 based on the prefix aggregation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1434
IETF has proposed a promising network-based mobility management method, called Proxy Mobile IPv6 (PMIPv6), which does not require any participation of mobile hosts in mobility-related signaling. However, it remains an open issue how to deploy the PMIPv6 while keeping optimized path route and low signaling costs. In this paper, we propose a Distributed PMIPv6 scheme based on the Prefix Aggregation, namely DPPA. In DPPA, all the LMAs in the extended home network are connected to each other via the global tunnel and announce their aggregated prefix to the Internet. Besides, by using the IP anycast routing, the signaling messages and data packets destined to any IP address that belongs to the aggregated prefix can be transmitted to the topologically closest LMA. Our analysis results show that DPPA has a more optimized path and lower location update cost and packet transmission cost when compared to PMIPv6.Adaptive multiple level mobility anchor point selection scheme in HMIPv6
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0945
Hierarchical Mobile IPv6 (HMIPv6) introduces a mobility anchor point (MAP) that localizes the signaling traffic and hence reduces the handoff latency. In addition to processing binding update messages from mobile nodes (MNs) on behalf of MNs' home agents (HAs), the MAP performs data traffic tunneling destined to or originated from MNs, both of which will burden the MAP substantially as the network size grow s. To provide scalable and robust mobile Internet services to a large number of visiting MNs, multiple MAPs will be deployed. In such an environment, how to select an appropriate MAP has a vital effect on the overall network performance. In this paper, we propose the adaptive multiple level MAP selection scheme in the form of binary tree structure. Then, we give the optimal threshold value calculation formula based on the total communication cost, which is used to select the MAP for MN. We compare its performance quantitatively in terms of signaling overhead. It can be shown that the adaptive multiple level MAP selection scheme is better than the furthest and the nearest MAP selection schemes in some area, since this scheme can be used to select the serving MAP depending on the MN's mobility and session activity. In addition, this MAP selection scheme is insensitive to the lower threshold value offseting.Coverage and networking analysis of TD-LTE system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0704
The development of mobile Internet and Internet of Things sharply increases needs of bandwidth and rate of mobile network. That demand for mobile data is motivating operators to pursue 4G solutions like TD-LTE to maintain the competitive edge. This paper analyzed coverage of TD-LTE system and further compared its performance with FDD LTE, studied the feasibility of intra frequency networking of TD-LTE system. At last, the paper provides suggestions on networking of TD-LTE system.Reliable data transmission against packet dropping misbehavior in wireless ad hoc networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0922
Many routing protocols in MANET have been proposed to resist packet dropping attacks by removing suspicious node from route. However, when they cannot discovery who is an adversary, they cannot effectively deal with packet dropping attacks launch by the adversary. In other words, when there is anyone type of packet dropping attacks they cannot resist, the packet delivery rate will be influenced. In view of this, we propose a novel scheme to mitigate the influence of any kind of packet dropping attacks in MANET. Further, our scheme can cooperate with other protocols to acquire better packet delivery rate and to decrease overheads. The security analysis and simulation study in this paper verify the effectiveness and efficiency of our scheme.