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Computing, Communications and Applications Conference (ComComAp), 2012

Date 11-13 Jan. 2012

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Displaying Results 1 - 25 of 89
  • Message from the ComComAp 2012 chairs

    Publication Year: 2012 , Page(s): 1
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  • Committe

    Publication Year: 2012 , Page(s): 1 - 2
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  • Sponsors

    Publication Year: 2012 , Page(s): 1
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  • Keynote speakers

    Publication Year: 2012 , Page(s): 1 - 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (197 KB)  

    Information technology (IT) is the acquisition, processing, storage, and dissemination of vocal, pictorial, textual, and numerical information by a combination of computing and telecommunications. Internet, Web, and Cloud are three main driving forces that reshape the landscape of IT. This transformation in IT has profound impact to how we process the information and provide information services for service providers, enterprises, and consumers. This in turn becomes the root source of innovations and advances for Internet, Web, and Cloud. View full abstract»

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  • Table of contents

    Publication Year: 2012 , Page(s): 1 - 11
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  • Author index

    Publication Year: 2012 , Page(s): 1 - 7
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  • [Copyright notice]

    Publication Year: 2012 , Page(s): 1
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  • Network calculus based QoS analysis of network coding in Cluster-tree wireless sensor network

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (500 KB) |  | HTML iconHTML  

    In resource-limited wireless sensor networks(WSNs), network resource will run out soon due to communication of mass redundant data. We employ Network Coding as an effective in-network processing strategy to reduce the data transmission amount. With this concern, a comprehensive Network-Calculus based analytical framework for Cluster-tree WSNs involving network coding is established in this paper. To specify, we firstly derive the service curve for sensor node performing network coding; then some useful performance expressions like input/output arrival curve, buffering requirements and end-to-end delay are calculated; finally, to show the effectiveness and superiority of our proposed analytical framework, we demonstrate how to apply the analytical framework to a special IEEE802.15.4/Zigbee protocol. Indeed, numerical results show that network coding does improve buffer requirement and end-to-end delay compared with classical scheduling strategy. View full abstract»

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  • Hierarchical flow balancing protocol for data aggregation in wireless sensor networks

    Publication Year: 2012 , Page(s): 7 - 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1395 KB) |  | HTML iconHTML  

    In this paper, we proposed a distributed hierarchical flow balancing (HFB) protocol for data aggregation in wireless sensor networks. A clustering algorithm is firstly proposed to group several sensors into one cluster based on the overlapping degrees of those sensors. Then, a backbone construction algorithm is proposed to construct a multi-level backbone network using the cluster heads. Furthermore, a flow balancing algorithm is designed to convey the sensed data from sensors to the sink. Lastly, a rerouting algorithm is proposed to reconstruct the network topology only around the locations where some cluster heads run out of their energy and drop out from the backbone. The proposed scheme has been evaluated in comparison with previous approaches using simulations. The simulation results show that HFB yields much longer lifetime than the others. View full abstract»

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  • Adaptive Hybrid Data Aggregation Policy for asynchronous MAC-based clustered sensor networks

    Publication Year: 2012 , Page(s): 13 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (769 KB) |  | HTML iconHTML  

    In Wireless Sensor Networks (WSNs), sensor nodes consume their limited battery energy for data transmission. Especially, the clustered sensor nodes in clustered sensor networks nearer the sink need to transmit data packets more frequently, because those functions as both sensor data generator and routers for data transmissions of other sensor nodes; subsequently, their faster energy depletion inevitably result in earlier turning off than others, so called the energy hole problem. Thus, it is imperative to adaptively control the number of data transmission of the clustered sensor nodes. To address this issue, this paper proposes an Adaptive Hybrid Data Aggregation Policy (AHDAP) that is designed to adjust the maximum size of data bursts to be transmitted according to the relative location of the clustered sensor node from the sink so that adaptively controlling the number of data transmission. The performance evaluation results show that the AHDAP can make the clustered sensor nodes nearer the sink result have smaller data transmission for better energy conservation. As a consequence, the AHDAP can achieve enhanced network sustainability as well as effectively extends lifetimes of the clustered sensor nodes by achieving its target performance. View full abstract»

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  • A novel data collection scheme with Cluster-based Separate Network Coding for WSNs

    Publication Year: 2012 , Page(s): 18 - 23
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (723 KB) |  | HTML iconHTML  

    In this paper, we present a novel Cluster-based Separate Networking Coding (CSNC) scheme, as a solution to solve the problem of continuous data collection for WSNs with a mobile BS. By separately encoding a certain number of data segments in a combined data segment and doing decoding-free data replacement, CSNC not only provides efficient storage method for continuous data, but also maintains a high success ratio of data collection. The comprehensive performance evaluation has been conducted through computer simulation. It is shown that CSNC outperforms the existing PNC scheme significantly. View full abstract»

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  • Kuhn-tucker conditions for nuclear norm optimization methods for interference alignment

    Publication Year: 2012 , Page(s): 24 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (458 KB) |  | HTML iconHTML  

    For designing optimized beamforming and zero forcing matrices for interference alignment, the usual way is to minimize the leakage interference. From the feasibility conditions of interference alignment, we have established equivalent conditions involving ranks of the interference and desired signal matrices and have proposed optimization of beamforming and zero-forcing matrices using ranks. Since minimization of rank of a matrix is a non-convex problem, it is approximated by a convex envelop of the rank which is the nuclear norm of the matrix. To maximize sum degrees of freedom for K users, we minimize the nuclear norm of sum of all interferences or simply minimizing the maximum nuclear norm of all interference matrices from all users. The nuclear norm of the desired signal matrix is constrained to be equal to the desired degrees of freedom, which guarantees a full rank matrix. We have developed the necessary and sufficient Kuhn-Tucker conditions for the optimization problems. We have also shown the convexity of our proposed optimization problems. View full abstract»

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  • Accurate bit-error rate estimation for residual wireless channels using partial FEC

    Publication Year: 2012 , Page(s): 30 - 34
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (362 KB) |  | HTML iconHTML  

    Real-time bit-error rate (BER) estimates of a wireless channel are required by many wireless applications and protocols. Surprisingly, however, there are very few estimation techniques that can accurately estimate the channel BER at residual channels above the physical layer. In this paper, we first show that traditional BER estimation techniques based on pilot bits, FEC and SNR cannot estimate a residual wireless channel's BER accurately. Therefore, we propose a novel, simple and accurate technique which estimates the BER by applying Partial FEC on disjoint sub-blocks of a packet. We analytically show that performance of any BER estimation technique is dependent on the number of bits used to infer BER and that the proposed scheme uses more bits to infer BER than the traditional methods under realistic channel conditions. We use a comprehensive 802.11b dataset to empirically compare the performance of the proposed scheme with other schemes. Simulation results validate our theoretical finding that the proposed scheme significantly outperforms traditional BER estimation techniques. View full abstract»

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  • From NS-2 to NS-3 - Implementation and evaluation

    Publication Year: 2012 , Page(s): 35 - 40
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1862 KB) |  | HTML iconHTML  

    NS-2 is the most famous simulator among other network simulators. Most of researchers use NS-2 to evaluate their new protocols/architectures. Although NS-2 has much resource and many available tools to generate different characteristics and network scenarios, source codes created on NS-2 is not able to be reused for real implementation. The releasing of NS-3 changes the way researchers work. NS-3 allows the researchers to work on both simulations and emulations with the same implementation and source codes. These can help researchers to evaluate their works on a single computer for simulation or on a real system without wasting their time to implement their works twice; one in NS-2 simulation and the other in real system. In this paper, we elaborate different points of protocol implementation between NS-2 and NS-3. We recommend a setting for mobility trace in order to obtain correct results between NS-2 and NS-3. Then, as a case study, we use DECA, which is a reliable broadcasting protocol for VANETs and previously implemented on NS-2. How to transfer DECA from NS-2 to NS-3 and how to validate its performance are shown. Moreover, an emulation of DECA on real system using NS-3 is described. The emulation results show a problem caused by asymmetric links which is not concerned in most of literatures. In this paper, therefore, we also propose a simple solution to help protocols' operation in the asymmetric link scenarios. The simulation results show that our solution can improve protocol performance. View full abstract»

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  • Managing access and usage controls in SNMP

    Publication Year: 2012 , Page(s): 41 - 47
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1060 KB) |  | HTML iconHTML  

    Simple Network Management Protocol “SNMP”, which is a component of the Internet Protocol Suite, is the most widely-used protocol in network management systems today. It is used to monitor network-attached devices such as routers, switches, Servers, workstations, printers, etc., for conditions that warrant administrative attention. In its initial versions, SNMPv1 and SNMPv2, SNMP was criticized for its lack of security, however, in its latest version, SNMPv3, it added important security features such as confidentiality, message integrity, authentication, and access control. In this paper we analyze the current approach, used by SNMP for providing access control, and we present new architecture that implements a new type of access control, called Usage Control (UCON), to better-control the access to the SNMP-managed environment at: pre-connection, during connection, and post connection. We believe that our proposed solution will enable owners of the SNMP-managed network to control who can access the system objects “i.e. the MIBs”, to control the activities of both the manager and the agent entities, and to help set some parameters to determine whether a communication between the agent and the manager can continue or should terminate. View full abstract»

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  • Non-access-stratum request attack in E-UTRAN

    Publication Year: 2012 , Page(s): 48 - 53
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (743 KB) |  | HTML iconHTML  

    Long Term Evolution (LTE) is the evolution of Universal Mobile Telecommunications System (UMTS). LTE revises and improves system architecture from UMTS to provide services that are more efficient. Evolved-UTRAN (E-UTRAN) is the air interface of 3GPP and it is on the upgrade path for LTE mobile networks. E-UTRAN specifies better security architecture to protect users' information. However, E-UTRAN is still not perfect. This article studies vulnerabilities of non-access-stratum (NAS) of E-UTRAN. We present illustrative attacks to exploit such vulnerabilities and demonstrate the effectiveness and the impact of such attacks on normal users by using our self-developed simulation tool. View full abstract»

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  • Design and performance evaluation of tag caching router architecture for CGM content

    Publication Year: 2012 , Page(s): 54 - 60
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (780 KB) |  | HTML iconHTML  

    In recent years, social interest in viewing consumer-generated media (CGM) contents has been rapidly growing, so their network traffic has been increasing considerably. To cope with this new increase in network traffic, we propose a tag caching router (TCR) architecture that supports folksonomies-based search and content caching for CGM content. Folksonomies are key words or metadata attached to the associated content by CGM-content creators, providers, and viewers to characterize the CGM content. The falksonomies-based search helps a user to find his/her interesting content because it automatically collects from the network the information of candidate contents with the folksonomy specified by the user and presents it as a content list to the user. The TCR architecture caches both content lists for content search and the associated contents for content downloading. We call this enhanced caching method as content caching. The performance of the proposed caching architecture was evaluated by performing a simulation for a wide variety of CGM contents with different traffic characteristics. The simulation results indicate that under a network model with 5 × 5 mesh-topology TCRs, content caching enables the TCR architecture combined with a conventional URI-based search to support a maximum of six-times more CGM access requests due to content caching than the number of accesses that can be supported by a conventional TCP/IP-based end-to-end architecture with a URI-based search. The number of accesses supported by the TCR architecture combined with folksonomies-based search increases to 17-times the number of accesses supported by the conventional TCP/IP-based end-to-end architecture with a URI-based search. View full abstract»

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  • Capacity bounds and stochastic resonance for binary input binary output channels

    Publication Year: 2012 , Page(s): 61 - 66
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB) |  | HTML iconHTML  

    In this paper, we discuss the threshold based stochastic resonance behavior of binary input, binary output discrete memoryless channels. We follow the basic model of Chapeau-Blondeau where he showed how the addition of external Gaussian noise could enhance channel capacity, thus providing an optimum channel capacity depending on both the threshold level and noise power of the system. In order to easily approximate channel capacity behavior, we use capacity bounds and approximations. View full abstract»

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  • Unidirectional flow throughput enhancement through Physical-Layer Network Coding

    Publication Year: 2012 , Page(s): 67 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1239 KB) |  | HTML iconHTML  

    The increasing demands for high data rates necessitate the development of faster schemes of exchanging information along wireless communication links. Physical-Layer Network Coding (PNC) is a promising technique that can improve the achievable data flow rates through higher packet transmission rates, thereby increasing the overall throughput. In this paper, we study the performance of the PNC transmission technique in unidirectional linear flow networks, and compare it with that of the traditional transmission technique. We first derive the bit-error rate (BER) that the PNC transmission scheme achieves, and then using that, we evaluate the end-to-end flow throughput of unidirectional flows. Our results show that PNC has a great potential for enhancing the achievable throughput, especially under medium to high signal-to-noise ratios. We also validate the derived BER results using simulations. View full abstract»

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  • Performances analysis of SEC based transmit diversity systems with MRC receivers

    Publication Year: 2012 , Page(s): 71 - 75
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (315 KB) |  | HTML iconHTML  

    Switch and Examine combining (SEC) diversity scheme is one of the simplest yet efficient diversity schemes. Earlier in [1] and [2], we proposed sequential power loading algorithm to reduce the average power used at the transmitter in transmit diversity systems. In this paper, we propose the usage of a maximum ratio combining (MRC) receiver on top of sequential power loading, and provide a complete performance analysis of this proposed scheme in terms of average power used, average number of used antennas, average feedback load, and outage probability. Numerical results show that the proposed MRC enhanced scheme provides lower average number of used antennas and average feedback load with better outage performance than post selection and early selection schemes that were proposed earlier. This improved performance comes at the expense of a slightly higher average transmit power used. View full abstract»

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  • An opportunistic feedback scheme for downlink coordinated scheduling/beamforming

    Publication Year: 2012 , Page(s): 76 - 80
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (498 KB) |  | HTML iconHTML  

    An opportunistic feedback scheme is proposed for reducing the uplink control information feedback for the coordinated scheduling/beamforming (CS/CB) mode in the coordinated multiple point (CoMP) systems. CoMP is a promising technology for LTE-Advanced to improve the coverage and the spectral efficiency. However, the total feedback load is substantially heavy and becomes a serious problem for the practical systems. The proposed opportunistic feedback scheme can reduce the feedback load with little user throughput deterioration. In the proposed feedback scheme, in each cooperating cells set, the cells are divided into one primary cell and several assistant cells. Users in the primary cell are fairly determined to feed back according to the normalized signal to interference plus noise ratio (SINR) threshold. In the assistant cells, users who cause less interference to the primary cell are supposed to feed back. The simulation results show that the proposed scheme reduces the feedback load magnificently, while keeping the performance loss minimal. View full abstract»

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  • A wireless Channel Allocation Algorithm with the Minimum Interference

    Publication Year: 2012 , Page(s): 81 - 84
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1895 KB) |  | HTML iconHTML  

    Wireless channel allocation plays as an important role in the design of wireless network, as it greatly influences the throughput and performance of the network. Based on the measurement over a small test-bed, we find the relationship between network throughput and interference. We introduce a wireless channel allocation model, which is able to minimize the network interference. Based on these works, we put forward to a new algorithm named WCAAMI (Wireless Channel Allocation Algorithm with the Minimum Interference), which can converge to a stable optimal point and obtain the better network performance. View full abstract»

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  • A new channel allocation scheme for mobility support in IEEE 802.11 wireless networks

    Publication Year: 2012 , Page(s): 85 - 89
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (855 KB) |  | HTML iconHTML  

    IEEE 802.11 wireless LANs can provide easy deployment and configuration for broadband wireless data services without dealing with a cable. However, when MSs roam in IEEE 802.11 wireless networks, the conventional handoff process is not suitable for seamless mobile services. In this paper, we propose a channel-switched AP architecture in which the neighboring APs cooperate in changing the RF channel periodically in a manner determined by an AP manager so that a MS can maintain a wireless connection to APs through a RF channel even if it moves to the neighboring AP service areas. Therefore, even though a MS moves between APs, it does not require the conventional handoff process since it recognizes all the APs as one AP. Performance results verify that the proposed scheme outperforms the conventional WLANs in the seamless mobility management. View full abstract»

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  • User QoE-based adaptive routing system for future Internet CDN

    Publication Year: 2012 , Page(s): 90 - 95
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1071 KB) |  | HTML iconHTML  

    The most important tendency of future Internet architectures is maintaining the best Quality of Experience (QoE), which represents the subjective perception of end-users using network services with network functions such as admission control, resource management, routing, traffic control, etc. Among of them, we focus on routing mechanism driven by QoE end-users. Nowadays, most existing routing protocols have encountered NP-complete problem when trying to satisfy multi QoS constraints criteria simultaneously. With the intention for avoiding the classification problem of these multiple criteria reducing the complexity problem for the future Internet, we propose a protocol based on user QoE measurement in routing paradigm to construct an adaptive and evolutionary system. Our approach, namely QQAR (QoE Q-learning based Adaptive Routing), is based on Q-Learning, a Reinforcement Learning algorithm. QQAR uses Pseudo Subjective Quality Assessment (PSQA), a real-time QoE assessment tool based on Random Neural Network, to evaluate QoE. Experimental results showed a significant performance against over other traditional routing protocols. View full abstract»

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  • Difference to sum ratio factor based min-sum decoding for Low Density Parity Check Codes

    Publication Year: 2012 , Page(s): 96 - 101
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (441 KB) |  | HTML iconHTML  

    Low Density Parity Check Codes (LDPC) give groundbreaking performance which is known to approach Shannon's limits for sufficiently large block length. Historically and recently, LDPC have been known to give superior performance than concatenated coding. In the following paper, a proposal to modify the standard Min-Sum (MS) algorithm for decoding LDPC codes is presented. This is done by introduction of a difference to sum ratio factor, κ in the check to bit node updating process. The algorithm is further extended by implementing hard decision of the Bit-Flipping (BF) algorithm over the soft decision of MS algorithm. Simulation results demonstrate that the proposed algorithms are effective in imparting a better performance in terms of a lower bit error rate (BER) at medium to high signal to noise ratio (SNR) when compared to the traditional MS algorithm while adding fair amount of complexity. View full abstract»

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