• ETRI Journal
• /
• v.20 no.2
• /
• pp.171-191
• /
• 1998

In this paper, we propose a new heuristic design algorithm for the virtual path (VP)-based ATM network with multiple traffic classes, in which QoS constraints associated with traffic class are taken into account. The minimum bandwidth of VP required to carry given amount of traffic is obtained by utilizing an equivalent bandwidth concept, and the route of each VP is placed so that the network cost is minimized while the QoS requirement is fulfilled To evaluate our design algorithm, we consider two kinds of traffic: voice traffic as low speed service and still picture traffic as high speed service. Through numerical examples, we demonstrate that our design method can achieve an efficient use of network resources, which results in providing a cost-effective VP-based ATM network.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.6 no.2
• /
• pp.11-17
• /
• 2010

In this paper, we propose efficient rate control algorithm for video near-lossless compression. The proposed method adjusts pixel error range using amounts of previous encoded bits and target bits at a slice encoding interval. Thus, encoded bits by the proposed method are transmitted well through limited bandwidth without overflow. Also, target bits and encoded bits can be controlled according to transmission policy. Experimental results show that our proposed method not only almost fits compression ratio, but also has better image quality.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.15 no.4
• /
• pp.93-101
• /
• 2019

This paper presents a software design and implementation of software-defined radio based IEEE 802.11ac encoder using Texas Instruments TMS320C6670 digital signal processor (DSP) platform. In this paper, the implemented encoder has the capability of generating all the signals consisting of preamble field and data field under different modulation & coding scheme in the IEEE 802.11ac standard. Moreover, the flexibility in choosing different rate, bandwidth, or mode can also be achieved by software reconfiguration using the DSP. As a result, by utilizing the computing power provided by multi-cores as well as the FFT coprocessors in the DSP, the required maximum throughput 78Mbps can be fully reached within 4 ㎲ for each OFDM symbol in the case of 20MHz bandwidth of IEEE 802.11ac.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.14 no.4
• /
• pp.93-99
• /
• 2018

This paper presents an implementation method using NDK (Network Developer's Kit) of GNU (GNU is Not Unix) Radio and Multicore DSP (Digital Signal Processor) to implement LTE (Long Term Evolution) SDR (Software Defined Radio) Platform. In order to satisfy 1.4MHz, 3MHz, 5MHz and 10MHz of the bandwidth supported by LTE, USRP (Universal Software Radio Peripheral) X series which is an RF (Radio Frequency) transceiver of Ettus Research was used. To control this, GNU Radio which is an open source software radio toolkit was used. We also used NDK from TI (Texas Instruments) DSP to transfer data between USRP and DSP. Experimental results show throughput results according to each bandwidth, thus confirming the feasibility of implementing LTE SDR Platform using GNU Radio and NDK of TI DSP.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.1A
• /
• pp.30-37
• /
• 2006

In this paper, we propose a QoS-aware efficient bandwidth re-provisioning scheme in a next generation wireless packet transport network. At the transport network layer, it classifies the traffic of the radio network layer into a real time class and a non-real time class. Using an auto-regressive time-series model and a given packet loss probability, our scheme predicts the needed bandwidth of the non-real time class at every re-provisioning interval. Our scheme increases the system capacity by releasing the unutilized bandwidth of the non-real time traffic class for the real-time traffic class while insuring a controllable upper bound on the packet loss probability of a non-real time traffic class. Through empirical evaluations using the real Internet traffic traces, our scheme is validated that it can increase the bandwidth efficiency while guaranteeing the quality of service requirements of the non-real time traffic class.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.2
• /
• pp.102-110
• /
• 2016

After Sewol ferry disaster occurred in April 2014, Korean government began investing to deploy LTE-based public safety network until the year of 2017. In order to reduce the operating and capital costs, resource sharing scheme among public safety network and commercial LTE networks is considered as one of the viable approaches. This thesis proposes a method of allocating bandwidth of public safety network based on various priorities required for disaster scenarios and stages in a resource sharing environment. In order to obtain the highest efficiency, we formulate the bandwidth allocation problem as a Fractional Knapsack Problem. Greedy algorithm was applied to solve the problem. For performance evaluation, we created several disaster scenarios and set suitable parameters for each scenario based on a disaster manual. The proposed method is compared with two typical methods, which are Class-based bandwidth allocation and Uniform bandwidth allocation. The results showed that the better performance in terms of the sum of the values and the amount of lost bytes.

• The KIPS Transactions:PartC
• /
• v.11C no.4
• /
• pp.555-562
• /
• 2004

We consider differentiated bandwidth allocation for a piconet in short-range wireless personal network systems : Bluetooth. Since bandwidth requirements nay vary among applications/services, and/or it may change over time, it is important to decide how to allocate limited resources to various service classes to meet their service requirements. We propose a simple and efficient bandwidth allocation mechanism which meets bandwidth requirements of various service types while saving power consumption by a Power saying mode, i.e., sniff node. We compare our proposed mechanism with a conventional (weighted) round-robin polling scheme and show that it achieves significant improvement of hroughput, delay, and power consumption.

• Journal of Digital Convergence
• /
• v.14 no.10
• /
• pp.303-310
• /
• 2016

Due to the ossification of the Internet, it is difficult to accommodate variety services. One of the efficient solution to this problem is network virtualization. It allows multiple parallel virtual networks to run on the shared physical infrastructure. It needs new resource allocation mechanism to share efficient physical resources. In this paper, we present efficient bandwidth allocation algorithm for virtual network request with high service priority. Our proposed algorithm can withdraw allocated bandwidth from low-level priority virtual network and maintain low-level virtual network service. We evaluated the performance of our proposed algorithm using simulation and found the improvement of approximately 8% acceptance rate.

• The KIPS Transactions:PartC
• /
• v.12C no.5 s.101
• /
• pp.725-732
• /
• 2005

This paper proposes an implementation methodology of the rate limiting method and the class-based bandwidth management for the gigabit-powered network processor, which are used on general purpose or ASIC systems in order to efficiently manage network bandwidth. Implementation and experiments are done on Intel's IXP1200 network processor. The result shows the accuracy of limited bandwidth and settling time of the estimator against the dynamic traffic rate. Through the results, this paper proves the proposed method and implementation properly work as expected.

• Journal of Internet Computing and Services
• /
• v.6 no.3
• /
• pp.121-128
• /
• 2005

Recently, as the research of effective resource management for supporting of various next generation internet service, the admission control mechanisms using the dynamic provisioning methods in differentiated service networks are studied. However, even though admission control mechanism is applied to the network, there exits the unfairness of call blocking probability among the different bandwidth requested services. In this paper, we propose the new admission control policy heuristic algorithm that provides fairness of call blocking probability between the large bandwidth requested service and the small bandwidth requested service. The simulation results show that the proposed algorithm provides not only blocking probability fairness but also high bandwidth utilization.