Now showing 1 - 10 of 15
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    Item type:Publication,
    An implementation of internet protocol options for self-authentication
    (2017-11-03)
    Thamthawornsakul, Parinya
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    This paper presents an enhancement of IP (Internet Protocol) standard to support user authentication within the protocol itself. The options field in an IP header is used for carrying specific data to add the ability of self-authentication. The specific data consist of a user identifier, a timestamp, and an HMAC calculated with important data in the IP header. The major purpose is to verify a device owner or a computer user in a local network in real time, before allowing access to restricted networks or the Internet. By this enhancement, the users can be authenticated at IP layer, without needing an additional user authentication process. The self-authentication ability provides a prevention of sending source-spoofed IP packet and also provides a high reliability of identifying the user. In addition, this ability does not require a creation of specific connection and an exchange of security parameters.
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    Backoff algorithm optimization for IEEE802.11 wireless local area networks
    (2012-10-02)
    Sartthong, Jesada
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    In this paper, we propose a new backoff algorithm for wireless local area networks (WLANs). The proposed algorithm develops by using mathematical optimization function theory on Carrier Sensing Multiple Accesses with Collision Avoidance and Request-to-Send Clear-to-Send protocol (CSMA/CA RTS CTS). A new backoff algorithm is named Contending Stations Backoff Algorithm (CSBA). The performance of CSBA compares with old backoff algorithms such as Binary Exponential Backoff algorithm (BEB), Double Increment Double Decrement Backoff algorithm (DIDD) and Estimation Based Backoff algorithm (EBB) by mathematical analysis. We analyze performance of CSBA in distribute coordination function mode for IEEE802.11a/b/g standards. Our numerical results indicate that the performance of CSBA algorithm is stable than old backoff algorithms in term of saturation throughput efficiency. © 2012 IEEE.
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    Application of power line communication with OFDM to smart grid system
    (2011-10-06)
    Maneerung, Amarisa
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    Hongesombut, Komsan
    Recently, power distribution grid is moving toward a smart grid where energy generation is decentralized and the grid adapts to demands. Due to the most cost-effective way for two-way communication, the use of power line distribution grid for data communication of smart meters has gained higher interests by utility companies. This paper presents the smart grid system with power line communication (PLC). The system serves as the communication infrastructure linking smart meters through the PLC network. The characteristics of PLC multipath channel and the noise model are presented. The smart meters and PLC are modeled based on the actual distribution grid data to set the model for analyzing the feasibility and performance of a smart grid. Orthogonal Frequency Division Multiplexing (OFDM) modulation technique is used to improve better performance and higher efficiency. Simulation results on different loading conditions have confirmed the performance of OFDM when operating in a power line channel in smart grid system. © 2011 IEEE.
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    MRC-MMSE detection in DF-cooperative communications with Rate 2/4 trellis coding
    (2010-07-30)
    Kamuang, Settakorn
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    This paper proposes the MRC-MMSE (Maximal Ratio Combining - Minimum Mean Squared Error) detection of the space time coding over Decode and Forward (DF) cooperative network channel with 16 states binary Rate 2/4 convolutional code. As we employed this convolutional code rate and Alamouti space time scheme, the transmitted signal can be created by two QPSK modulators instead of 16 - PSK or 16-QAM technique. When relay node has detection error, the system is biased. MRC-MMSE detection can reduce this effect. Numerical results show that the proposed technique significantly reduces error rate performance. Additionally, this technique does not require any bandwidth expansion.
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    Item type:Publication,
    Performance Analysis of ALOHA Framework under Limited Access of Data Transmission for Active RFID System
    (2016-01-01)
    Sriwan, Apisit
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    The data collision of multiple tags to access the channel is one of the most problems in active Radio Frequency Identification (RFID). The technique of random tag is based on William Feller equation by considering the successful probability (Psuc) may affect to increase the data collision if the tag is not limited the privilege. This paper proposes the modification of William Feller equation by dividing the privilege of tags into several groups. The results show that our scheme can provide the better performances as comparing with William Feller equation in term of successful probability. The maximum average of successful probability is more than 0.97.
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    Performance analysis of random slot multiple access algorithms for DOCSIS protocol
    This paper proposes the analysis of random slot multiple access algorithms for DOCSIS (Data-Over-Cable Service Interface Specifications) protocol. These algorithms are the contention mini - slots resolution algorithms that uniformly generate probability p of each user need to send a request. They can increase an efficiency of mini-slot access. In this paper, we analyze efficiency of these algorithms by consideration of throughput and delay of system. And, the analysis results provide a comparative evaluation of the Truncated Binary Exponential Back - off (TBEB) that is widely studied algorithm for DOCSIS protocol. © 2011 IEEE.
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    Item type:Publication,
    Several contention window adjustment techniques for improving unsaturated throughput of wireless LANs
    (2014-01-01)
    Sartthong, Jesada
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    Chirdchoo, Nitthita
    This paper proposes the several contention window adjustment schemes in backoff process as well-known backoff algorithm (BA) for improving the performance of wireless local area network (WLAN). In addition, this research introduces a new unsaturated discrete Markov chain model in fixed backoff stages and fixed contention window sizes technique (FBFC). The proposed contention window adjustment schemes are designed by applying the moment generating function concept in random variable and process theorem. Unsaturated throughput parameters are used to compare the performance of all contention window size adjustment techniques based on IEEE802.11b WLAN standards. The comparison results show that Bernoulli and Double adjustment schemes are good contention window size adjustments at light traffic load, and the Even contention window size adjustment operates well at high traffic load condition. © (2014) Trans Tech Publications, Switzerland.
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    A new method for image communication via low bit rate channel
    (2017-02-21)
    Boonjanawirod, Panithan
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    Srithanasarn, Krittanik
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    This article presents a new method for image communication via low bit rate channel that transfer JPEG image to buffered Image storage and encoding to Byte Array Output Stream then receiving byte Array data that ready to transfer by used Byte Array processing method. Then Byte Array will be transferred via serial port with Low Bit Rate channel to destination. After destination received data, the data will be changed Byte Array to Byte Array Output Stream by using Byte Array processing method as same as source data. Then, Byte Array Output Stream is decoded and transferred to Buffered Image storage for showing the result. This article also presents about Byte Array modification and the correct result.
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    Item type:Publication,
    A boundary of saturated and unsaturated throughput in IEEE802.11 wireless LAN channel
    (2015-01-26)
    Sartthong, Jesada
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    Throughput is an important parameter that it is used to measure the performance of wireless local network (WLAN). In this research, we proposes a new discrete time Markov chain model to calculate the boundary of saturated and unsaturated throughput efficiencies in WLAN channel. Both throughput parameters are compared in fixed back off stages and fixed contention window sizes (FBFC) technique by applying the global balance equation concept in steady-state distribution of discrete time Markov chain model. Also, the collision resolution method of transmitted packets through WLAN channel uses the Binary Exponential Back off (BEB) algorithm based on Carrier Sense Multiple Accesses with Collision Avoidance (CSMA/CA) protocol. Our numerical results show that the throughput of unsaturated channel is higher than the saturated channel at light traffic load. On the contrary, the throughput of unsaturated channel is less than the saturated channel at high traffic loads condition.
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    Item type:Publication,
    A design of self-authenticated Internet Protocol for Network Access Control
    (2016-09-06)
    Thamthawornsakul, Parinya
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    This paper presents an application of Internet Protocol Options for enhancing self-authenticated feature to the Internet Protocol. The options consist of Keyed-Hash Message Authentication Code and timestamp. In the network access control system, local network devices needing to access protected networks have to attach the options to packet header before sending to destination through a network access controller or commonly known as a gateway. Internet Protocol packets with options are verified on the gateway, the Keyed-Hash Message Authentication Code is used for checking integrity of data and the timestamp is used for replay attack mitigation. Packets passing all processes would be allowed to access to the protected networks. The design of self-authenticated Internet Protocol provides a protection of sending source spoofed packets from local network causing damage to other networks and also provides high reliability of source identification.