• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4572-4586
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• 2019

Mobile Edge Computing (MEC) and Information-Centric Networking (ICN) are essential network architectures for the future Internet. The advantages of MEC and ICN such as computation and storage capabilities at the edge of the network, in-network caching and named-data communication paradigm can greatly improve the quality of video streaming applications. However, the packet loss in wireless network environments still affects the video streaming performance and the existing loss recovery approaches in ICN does not exploit the capabilities of MEC. This paper proposes a Deep Learning based Loss Recovery Mechanism (DL-LRM) for video streaming over MEC based ICN. Different with existing approaches, the Forward Error Correction (FEC) packets are generated at the edge of the network, which dramatically reduces the workload of core network and backhaul. By monitoring network states, our proposed DL-LRM controls the FEC request rate by deep reinforcement learning algorithm. Considering the characteristics of video streaming and MEC, in this paper we develop content caching detection and fast retransmission algorithm to effectively utilize resources of MEC. Experimental results demonstrate that the DL-LRM is able to adaptively adjust and control the FEC request rate and achieve better video quality than the existing approaches.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.101-112
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• 2022

In this paper, we analyze 5G network slicing and propose an efficient network slice configuration method in 5G mobile networks. Network slicing can be identified and performed based on the network slice instance information in 5G mobile networks. In case of discordance between the UE's network slice instance information and the network's one, the unnecessary signalling overhead occurs, when the UE's PDU Session Establishment request to the network fails. To solve this problem, this paper proposes two efficient network slice configuration methods, the UE-based ENSC(Efficient Network Slice Configuration) method and the Network-based ENSC method. The proposed schemes perform the prompt the configuration and provision of the updated network slice instance information between the UE and network and improve battery and resource efficiency and minimize unnecessary signalling overhead compared to existing methods in 5G mobile networks.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.562-566
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• 2011

As telecommunication technologies in telemedicine services are developed, the expeditious development of wireless and mobile networks has stimulated wide applications of mobile electronic healthcare systems. However, security is an essential system requirement since many patients have privacy concerns when it comes to releasing their personal information over the open wireless channels. Due to the invisible feature of mobile signals, hackers have easier access to hospital networks than wired network systems. This may result in several security incidents unless security protocols are well prepared. In this paper, we analyzed authentication and authorization procedures for healthcare system architecture to apply secure M-health systems in the hospital environment. From the analyses, we estimate optimal requirements as a countermeasure to its vulnerabilities.

• ETRI Journal
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• v.19 no.3
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• pp.98-115
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• 1997

The architecture of the CDMA mobile system (CMS) is developed based on three function groups - service resource, service control, and service management groups. In this paper, the CMS architecture is discussed from the point of view of implementing these functions. The variable length packets are used for transmission. The synchronization clock signals are derived form the GPS receiver. The open loop and closed loop techniques are used for the power control. The internationally accepted signaling and network protocols are employed. The call control for the primary services in designed to provide efficient mobile telecommunication services. The softer handoff is implemented in one card. The mobile assisted handoff and the network assisted handoff are employed in the soft and hard handoffs. The authentication is based on the secret data which includes random numbers. The management functions, which include the location management, resource management, cell boundary management and OAM management, are implemented to warrant the system efficiency, maximum capacity and high reliability. The architecture ensures that the CMS is flexible and expandable to provide subscribers with economic and efficient system configuration. The dynamic power control, adaptive channel allocation. and dynamic cell boundary management are recommended for future work.

• ETRI Journal
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• v.19 no.3
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• pp.116-140
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• 1997

The base station transceiver subsystem (BTS) of the CDMA Mobile System is interfaced to mobile stations over the air and to the wired network through a packet switched interconnection network. The potential benefits of CDMA technology are achieved when the transmitter and the receiver are properly designed and implemented. The physical layer of the interface at the base station is implemented with the CDMA ASICs and control circuits in channel card of the BTS. We present the design perspectives and structural illustration of the BTS. Base station modem ASICs and their control to implement the CDMA receiver, Baseband and RF signal processing blocks, and BTS controller are described. Elaborate power control is essential to ensure the high capacity which is one of advantages of the CDMA technology. The closed loop reverse link power control and the forward link power control operated in the BTS are described.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.457-460
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• 2011

For the mobile meteorological services, sensed data should be gathered at a server from various clients like as Ubiquitous Sensor Network, mobile phone or public traffic vehicle by wireless network. The gathered data at server have huge volume and increase continuously. Therefore, a special query method and data structure should be considered. This paper studies on all possible query type on the data and processing steps for the mobile meteorological services. Some query spaces will be discussed. After that, this paper proposes effective data structure for the sensed data to support the query types.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.69-72
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• 2008

In the paper, embedded system that manage, control the status of vehicle through internet and mobile instruments are designed. The network is composed of the distributed control system using CAN communication, where communication is possible with two lines, and the bluetooth, where wireless communication is possible. We also designed the Embedded system to make up the web server only for the vehicle, made it possible to catch hold of the conditions of the vehicle and control the vehicle through internet by interfacing the destributed controller. We also made such a Web Server possible th be monitored and controlled by the mobile instruments such as PDA, mobile phones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.10
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• pp.2205-2218
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• 1997

We implement the CARMA-M (Collision Avoidance Radio Multiple Access-Mobile) protocol and DMP (Data-radio Multiplex Protocol) with a client/server architecture for a wireless communication netowrk. These protocols support a data transfer function between a remote computer and a mobile portable computer with a wireless modem which are proposed by dataradio in U.S.A. With the review and analysis of the proposed protocol, the impelementation methods of DMP, CARMA-M and LLC to interface the protocols are presented. Moreover the FEC technique is added to find and correct the errors generated in communication. The simulation method of a wireless network using wires is also shown to verify the implemented protocols.

• ETRI Journal
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• v.42 no.5
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• pp.712-720
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• 2020

Recently, to make the best use of limited and precious spectrum resources, spectrum sharing between satellite and cellular networks has received much interest. In this study, we mathematically analyze the success probability of a fixed (satellite) earth station (FES) based on a stochastic geometry framework. Both the FES and base stations (BSs) are assumed to be equipped with a directional antenna, and the location and the number of BSs are modeled based on the Poisson point process. Furthermore, an exclusion zone is considered, in which the BSs are prohibited from locating in a circular zone with a certain radius around the FES to protect it from severe interference from the cellular BSs. We validate the analytical results on the success probability of the cognitive satellite-terrestrial network with directional antennas by comparing it using extensive computer simulations and show the effect of the exclusion zone on the success probability at the FES. It is shown that the exclusion zone-based interference mitigation technique significantly improves the success probability as the exclusion zone increases.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.530-530
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• 2006