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Network Infrastructure and Digital Content (IC-NIDC), 2012 3rd IEEE International Conference on

Date 21-23 Sept. 2012

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Displaying Results 1 - 25 of 147
  • HCEM: A new class of bit-level hybrid channel error model

    Publication Year: 2012 , Page(s): 8 - 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (369 KB) |  | HTML iconHTML  

    In this paper we present a bit-level hybrid channel error model (HCEM) to represent multipath fading wireless channels. Our model divides the received error marking sequences into blocks of different lengths. Within each block, bit errors occur according to the independent model with mean bit error rate e. We define p to be a threshold bit error rate and if the bit error rate of a block is not greater than p, we associate it with a benign block and vice versa. For any block being of length n, we compute the probability PG it is a benign block and the probability PB it is a malign block. Between blocks, we define a new class of two-state Markov channel model. It adopts a benign block state G and a malign block state B. We take PG and PB as approximate values of the steady-state probability of being a benign block state and a malign block state respectively. For an error marking sequence, we show basic principles of choosing suited model parameters: (n, p, e) in theory. We set up an office wireless environment and show how to choose optimum model parameters: (n, p, e) based on data. View full abstract»

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  • On the coverage area in broadcast ad hoc networks

    Publication Year: 2012 , Page(s): 13 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (385 KB) |  | HTML iconHTML  

    In this paper, we first define the problem of computation of the potential hidden node area and the extra coverage area that can benefit from rebroadcasts in broadcast ad hoc networks and abstract two types of computations as a geometric coverage area computation problem. Then, under two distinct distributions of the nodes in the network, we derive the closed-form expressions of the cumulative distribution functions and the probability density functions of the distance between the source node and the nodes (especially, the farthest node) within its transmission range. Finally, the defined coverage area can be derived through the density functions in one-dimensional case. This calculation can be beneficial to the design and analysis of multi-hop broadcast ad hoc networks. View full abstract»

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  • An improved AODVjr algorithm for extending network lifetime

    Publication Year: 2012 , Page(s): 18 - 21
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (834 KB) |  | HTML iconHTML  

    Simple and flexible as AODVjr is, it is used in Zigbee mesh networks as the routing mechanism. To reduce and balance the network's energy consumption, many improved energy-aware routing algorithms have been presented based on AODVjr. However, they paid little attention to the excessive energy consumption of low-energy nodes caused by RREQ flooding which may result in network earlier death. To deal with this problem, we propose an improved energy-aware routing algorithm, EG-AODVjr, to extend the whole network lifetime by eliminating the unnecessary RREQ overhead of low-energy nodes. In EG-AODVjr, nodes are classified into four grades according to its remaining energy and adopt different RREQ processing mechanisms separately due to its grade to prevent low-energy nodes from wasting energy on forwarding RREQ packets. Furthermore, we modify the path selected scheme by putting forward a new method to calculate the path cost. EG-AODVjr is simulated and the results show that it can prolong the network lifetime by 26.1% compared with that of original AODVjr, achieving a better performance on extending Zigbee network lifetime. View full abstract»

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  • Improvement of LEACH protocol based on uneven clustering algorithm

    Publication Year: 2012 , Page(s): 22 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (975 KB) |  | HTML iconHTML  

    In this paper, we analyze the defects of LEACH protocol and clustering based on RSSI ranging algorithm. Mainly considering the network load balance, the residual energy and protocol overhead factors, an improved protocol is proposed based on LEACH protocol and uneven clustering. By simulating the improved protocol, a conclusion is drawn that the number of cluster head generated by the improved protocol is more stable than that of the unimproved LEACH protocol, and the improved protocol can extend the network lifetime effectively. View full abstract»

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  • A clustering scheme for Reachback Firefly Synchronicity in wireless sensor networks

    Publication Year: 2012 , Page(s): 27 - 31
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1214 KB) |  | HTML iconHTML  

    The firefly algorithm has become a hot issue in the research of wireless sensor networks (WSN) synchronization recently. In this paper, a clustering scheme is introduced to Reachback Firefly Algorithm (RFA), and this newly proposed algorithm is clustering firefly synchronization algorithm (CFSA). At the beginning of CFSA, the initial phases of all nodes in the network are sequenced for the purpose of calculating the number of clusters required. Then the entire network is divided into several clusters. Thus the original synchronization process can be decomposed into the following two steps: Cluster-intra synchronization and Cluster-inter synchronization. The simulation results show that CFSA improves the convergence rate of the system. Meanwhile, it effectively reduces the number of flashes, which leads to the mitigation in the overall network load. View full abstract»

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  • SIDES: Scalable Intelligent Distributed Emergency System

    Publication Year: 2012 , Page(s): 32 - 38
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3030 KB) |  | HTML iconHTML  

    Nowadays, evacuation is mostly based on individual decisions, which is unreliable. This paper introduces a practical solution towards emergency evacuation by guiding people out of building efficiently. Built on wireless sensor network (WSN), our system is capable of learning and dynamically generating evacuation strategy. Distributed mechanism and backup mechanism feature the scalability and invulnerability. Simulations prove the efficiency and reliability of the system. View full abstract»

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  • DNCA: An efficient channel assignment for multi-interface multi-channel Ad Hoc wireless networks

    Publication Year: 2012 , Page(s): 39 - 43
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (613 KB) |  | HTML iconHTML  

    The capacity of an IEEE 802.11-based multi-hop wireless network is limited. By effectively utilizing multiple non-overlapping channels and multiple interfaces, collision and co-channel interference can be reduced. This allows more concurrent transmissions and thus enhances the network throughput. In this paper, we introduce an efficient distributed negotiated channel assignment protocol, called DNCA. At each node, DNCA conducts a local optimization by greedy balancing the number of neighbors on each interface. By using DNCA, it does not require changes to higher-level protocols. We describe the design and implementation of DNCA, and analyze its performance using ns-3 network simulator. Our results show that DNCA provides much higher system capacity and lower end-to-end packet delay. View full abstract»

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  • Evaluation and improvement of QoS metrics for safety-critical broadcast services in VANETs

    Publication Year: 2012 , Page(s): 44 - 48
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (891 KB) |  | HTML iconHTML  

    Quality of service (QoS) is an important issue for safety-critical broadcast services in vehicular ad hoc networks (VANETs). Unlike traditional wireless network applications, vehicular safety-related communication requires faster and more reliable message delivery, and it usually demands broadcast communication. However, there is few QoS metrics specifically for vehicular safety communications, and the current channel access scheme defined in IEEE 1609.4 cannot meet these requirements well. In this paper, we first introduce three QoS metrics specifically for one-hop safety broadcast communication in VANETs, including the packet success rate (PSR), the packet transmission rate (PTR) and the packet loss percentage (PLP). Then, we proposed an adaptive independent channel switching scheme to improve QoS of vehicular safety communications. Simulation results show that our proposed scheme outperforms the current IEEE 802.11p/1609.x protocol stacks in terms of PSR, PTR and PLP. View full abstract»

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  • Power constrained optimal traffic allocation for multi-access utilization of multi-mode terminals

    Publication Year: 2012 , Page(s): 49 - 53
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (981 KB) |  | HTML iconHTML  

    In heterogeneous wireless networks, data transmission performance can be enhanced through the multi-access utilization of multi-mode terminals, it is carried out by the simultaneous employment of multiple parallel links over terminal's multiple radio access technologies. Promoting the multi-mode terminal's transmission performance while ensuring its energy efficiency is focused in this paper, we design a multiaccess transmission model and formulate the transmission delay minimization problem under the total data transmission rate demand and total transmission power constraint. An optimal traffic allocation algorithm using a modified particle swarm method is conducted to dynamically allocate traffic arrival rate for terminal's each radio access technology. Compared with the traditional algorithm, simulation results show that the proposed algorithm is efficient, and can significantly reduce the transmission delay while guaranteeing the total transmission power constraint. View full abstract»

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  • Utilization of null subcarriers for PAPR reduction in 3GPP LTE downlink

    Publication Year: 2012 , Page(s): 54 - 56
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    The multiple access scheme for the long term evolution (LTE) physical layer is based on Orthogonal Frequency Division Multiple Access (OFDMA) in the downlink. The main drawback of OFDMA is the peak-to-average power ratio (PAPR) problem. Dummy sequence insertion (DSI) concept can be an efficient PAPR reduction method for the LTE downlink system because it is very simple to implement and side information is not needed. However, the DSI has to sacrifice a decrease in the transmitted data rate for a large number of dummy subcarriers. In this paper, a novel approach to the DSI concept is proposed for complete application to an LTE system. For effective utilization of physical resources, the unused space of the LTE system is calculated, and dummy subcarriers are inserted into the unused space. Therefore, there is no degradation in transmitted data rate. Simulation results show that the proposed method can reduce PAPR considerably without degradation of bit error rate (BER) performance as a LTE downlink system. View full abstract»

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  • Fingerprint-based location positoning using improved KNN

    Publication Year: 2012 , Page(s): 57 - 61
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (561 KB) |  | HTML iconHTML  

    Location estimation has become one of the most popular research areas for the wide application of Location Based Services (LBS). K nearest neighbors (KNN) algorithm is commonly used in fingerprinting approach, and it has been widely used for decades due to its simplicity and effectiveness. However, the main drawback of KNN algorithm is obvious. Theoretical behavior can hardly be obtained because KNN is sensitive to the value of K and it often fails to work well with inappropriate choice of distance metric or due to the presence of numerous irrelevant features. In order to fill this gap, an improved KNN algorithm is introduced. And this algorithm is beneficial to location estimation in a real GSM network. View full abstract»

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  • Design of an antenna for an ingestible capsule endoscope system

    Publication Year: 2012 , Page(s): 62 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1928 KB) |  | HTML iconHTML  

    In this paper, an antenna used in an ingestible capsule endoscope system is proposed. To achieve miniaturization and a wide bandwidth, an inverted-F antenna with a meandered strip line was used. The antenna performance in a human voxel model is analyzed through simulation. In order to investigate the performance of the proposed antenna in an indoor environment, a typical sickroom model is setup, and the propagation characteristics between the proposed antenna and the base station are analyzed at 1.4 GHz. The performance of the fabricated antenna is verified by comparing the measured data with that of the simulation when the antenna is placed in a human-equivalent liquid phantom. View full abstract»

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  • Base station switching based dynamic energy saving algorithm for cellular networks

    Publication Year: 2012 , Page(s): 66 - 70
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1225 KB) |  | HTML iconHTML  

    Switching the base station (BS) with low traffic into sleep mode is considered as one of the most promising technologies for energy saving in the cellular networks. In this paper, we focus on the switching method considering the quality of service (QoS) as well as energy saving of the whole network. The network topology is modeled as a weighted affinity graph to describe the possible associations of user equipment (UEs) and the BSs in the network. Then the maximization problem of the network performance valued by the QoS and energy saving is formulated. Based on that, a dynamic energy saving (DES) algorithm is proposed. After optimized by DES, the network is reconfigured by switching certain BSs into sleep mode. Simulation results under different traffic conditions demonstrate that the proposed DES algorithm can significantly reduce energy consumption and improve the energy efficiency. View full abstract»

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  • Performance analysis and optimization of DRX mechanism in LTE

    Publication Year: 2012 , Page(s): 71 - 75
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1235 KB) |  | HTML iconHTML  

    To extend user equipment (UE) battery's lifetime, discontinuous reception (DRX) mechanism is employed in Long Term Evolution (LTE) system. In this paper, we propose an analytical model which mainly focuses on the inactivity period. Based on the model, a cost function that considers both energy consumption and response delay is presented. Hence, the target to investigate the proper selection of DRX parameters transforms into a cost minimization problem. We solve the problem with specific constraints. Finally, some numerical results are shown to illustrate that optimizing parameters can make performance improved. By comparing these results, the impact of different parameters on performance is studied. View full abstract»

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  • Nash bargaining solution based subcarrier allocation for uplink SC-FDMA distributed antenna network

    Publication Year: 2012 , Page(s): 76 - 80
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1188 KB) |  | HTML iconHTML  

    The system capacity of single-carrier frequency division multiple access (SC-FDMA) can be increased by allocating subcarriers to users who are in a good channel condition. However, there is a tradeoff between system capacity and fairness among users. Nash bargaining solution (NBS) in cooperative game theory can be used to solve this tradeoff problem. However, very high computational complexity is required to find the NBS. In this paper, we propose a reduced complexity suboptimal NBS based subcarrier allocation, which requires lower computational complexity while achieving the system capacity and fairness among users similar to the NBS. The proposed suboptimal NBS subcarrier allocation is applied to distributed antenna network (DAN) using frequency-domain space-time transmit diversity (FD-STTD). Numerical computation results show that the proposed NBS based subcarrier allocation achieves the system capacity comparable to Proportionally Fair (PF) map while achieving a higher fairness than PF map. View full abstract»

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  • Performance analysis on FDE receiver for single carrier transmission

    Publication Year: 2012 , Page(s): 81 - 84
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (254 KB) |  | HTML iconHTML  

    In this paper, single carrier (SC) transmission is considered. We focus on SC frequency domain equalization (FDE) receiver and analyze the signal to noise ratio (SNR) of the time domain output signal estimate and then, derive the achievable bit error rate (BER). For the purpose of comparison, we consider optimal time domain equalization (TDE) receiver as a reference. Our analytical results show the relationship between the FDE and optimal TDE. View full abstract»

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  • Performance of channel adaptive random access with sequence collision

    Publication Year: 2012 , Page(s): 85 - 88
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (579 KB) |  | HTML iconHTML  

    Channel adaptive random access can decrease the required power for random access transmission in TDD (Time Division Duplex) based wireless communication systems [1]. In this paper, the performance of channel adaptive random access is investigated considering the effect of sequence collision. View full abstract»

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  • A neighbor peer selection algorithm based on load balance in mobile p2p streaming

    Publication Year: 2012 , Page(s): 89 - 93
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1310 KB) |  | HTML iconHTML  

    In mobile peer to peer streaming system, to solve the influence brought by the load difference among cells, a neighbor peer selection algorithm based on load balance is proposed. In the strategy, the comprehensive evaluation value of the candidate peer is achieved through the use of gray relation analysis theory on multi-attribute decision matrix including load balance degree, and then the neighbor peer list is got through ranking the comprehensive evaluation value. Simulation results show that with the peer selection scheme in mobile p2p streaming system, the system's bandwidth utilization and the user's average throughput are improved. View full abstract»

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  • A novel planar tunable bandstop filter based on simple coupled-line structure

    Publication Year: 2012 , Page(s): 94 - 96
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (874 KB) |  | HTML iconHTML  

    A simple coupled-line structure is proposed to construct a novel planar bandstop filter. The reconfigurable performance is achieved by using tunable capacitors, namely, varactor diodes. The stopband of this filter can be tuned from 0.6 to 1.57 GHz when the capacitance of capacitors is in the range of 1 to 7 pF. Both simulated and measured results verify this proposed idea. View full abstract»

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  • Interworking of Voice over Sensor Network (VoSN) using the TDMA/TDD MAC and VoIP based SIP

    Publication Year: 2012 , Page(s): 97 - 101
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1172 KB) |  | HTML iconHTML  

    In this paper, we suggest a newly Voice Network Protocol (VNP) based on Session Initiation Protocol (SIP) using TDMA/TDD MAC protocol. VNP is implemented on mobile devices and VoSN Base Station for session management among large-scale VoSN users and interworking with VoIP based on SIP. We have tested our large-scale VoSN system and found that the packet delay is approximately less than 110ms. View full abstract»

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  • A design of the full-duplex voice mixer for multi-user voice over sensor networks (VoSN) systems

    Publication Year: 2012 , Page(s): 102 - 105
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1098 KB) |  | HTML iconHTML  

    As increasing the need of multimedia such as voice data using wireless sensor network, the research about voice over sensor network (VoSN) has been conducted widely. In this paper, we design a full-duplex voice mixer for multi-user VoSN system as group communication and describe the issues about implementation such as hardware configuration, medium access control (MAC) protocol, and synchronization among multiple users. To measure the quality of designed system, we conduct an experiment using sine wave. As result of an experiment, we expect that a variety of applications can be developed using presented system. View full abstract»

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  • A novel OTDOA positioning scheme in Heterogeneous LTE-Advanced systems

    Publication Year: 2012 , Page(s): 106 - 110
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1965 KB) |  | HTML iconHTML  

    The Observed Time Difference of Arrival (OTDOA) as a major positioning method in 3rd Generation Partnership Project (3GPP) specification has been deeply researched in Long Term Evolution Advanced (LTE-A) system. This paper analyzes the new interference scenarios in Heterogeneous Network (Het-Net) and the drawbacks of conventional OTDOA method which are caused by LPN (Low Power Nodes) deployed in Het-Net. In this paper, we propose a Time division multiplex (TDM) and a Code division multiplex (CDM) scheme for positioning reference signal (PRS) transmitting to solve these problems in Het-Net. Simulation results show that the proposed scheme can greatly improve the positioning accuracy compared with the conventional method and its performance meets the Federal communication commission (FCC) requirement. View full abstract»

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  • Energy-efficient power allocation for the Uplink of Distributed Antenna Systems

    Publication Year: 2012 , Page(s): 111 - 115
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (578 KB) |  | HTML iconHTML  

    In this letter, we investigate the tradeoff between energy efficiency (EE) and spectral efficiency (SE) in the Uplink of Distributed Antenna Systems with uniformly distributed Uts over the MIMO Rayleigh Fading Channel, and then demonstrate the derived closed-form approximation (CFA)'s accuracy when comparing with the nearly exact EE in the realistic power consumption models. Using this CFA, we get a low complexity and high efficiency approximate method to address the maximum energy-efficient power allocation policy by accurately approximating the transmit power in closed-form when considering that the aggregate number of transmitted antennas and received antennas are equal in the uplink. View full abstract»

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  • Delay constrained throughput analysis of SISO

    Publication Year: 2012 , Page(s): 116 - 121
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1308 KB) |  | HTML iconHTML  

    We analyze the traffic carrying capacity of a single-input single-output system for a given delay guarantee at the flow level. A continuous time ON/OFF data source is considered as the traffic model while the wireless channel is modeled using the Gilbert-Elliot model. We study the impact of the delay bound violation probability, traffic burstiness, channel memory and the delay requirements at the network layer on the throughput under different signal strength. View full abstract»

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  • A dynamic Priority update Granularity adjustment algorithm based on user density and service delay requirement in LTE downlink scheduling

    Publication Year: 2012 , Page(s): 122 - 127
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1804 KB) |  | HTML iconHTML  

    LTE is a Long Term Evolution of wireless technology developed by 3GPP. In order to achieve the rapid growth of subscriber number and the ever increasing need for higher data rates, an ideal scheduling algorithm is needed for LTE system. In this article, we propose a new factor, Priority Upgrade Granularity (PUG), whose value influences the scheduling performance greatly. In addition, a dynamic PUG adjustment method according to user density and service delay requirement are presented. Numerous simulation results witness the increase in system throughput and user fairness compared with three widely used scheduling schemes, i.e. max C/I, Round Robin (RR) and Proportion Fair (PF). View full abstract»

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