• Journal of Communications and Networks
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• 제17권3호
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• pp.306-320
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• 2015

Due to an explosive growth in services running in different datacenters, there is need for service selection and routing to deliver user requests to the best service instance. In current solutions, it is generally the client that must first select a datacenter to forward the request to before an internal load-balancer of the selected datacenter can select the optimal instance. An optimal selection requires knowledge of both network and server characteristics, making clients less suitable to make this decision. Information-Centric Networking (ICN) research solved a similar selection problem for static data retrieval by integrating content delivery as a native network feature. We address the selection problem for services by extending the ICN-principles for services. In this paper we present Queue and Latency, a network-driven service selection algorithm which maps user demand to service instances, taking into account both network and server metrics. To reduce the size of service router forwarding tables, we present a statistical method to approximate an optimal load distribution with minimized router state required. Simulation results show that our statistical routing approach approximates the average system response time of source-based routing with minimized state in forwarding tables.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Journal of Communications and Networks
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• 제6권4호
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• pp.331-342
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• 2004

We study the problem of controlling data overhead of mesh-based multicast ad hoc routing protocols by adaptively adding redundancy to the minimal data overhead multicast mesh as required by the network conditions. We show that the computation of the minimal data overhead multicast mesh is NP-complete, and we propose an heuristic approximation algorithm inspired on epidemic algorithms. In addition, we propose a mobility-aware and adaptive mesh construction algorithm based on a probabilistic path selection being able to adapt the reliability of the multicast mesh to the mobility of the network. Our simulation results show that the proposed approach, when implemented into ODMRP, is able to offer similar performance results and a lower average latency while reducing data overhead between 25 to 50% compared to the original ODMRP.

• 인터넷정보학회논문지
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• 제21권4호
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• pp.1-8
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• 2020

5G 목표 중 하나인 초신뢰성 저지연 통신에 도달하기 위해 멀티액세스 엣지 컴퓨팅 패러다임이 탄생했다. 이 패러다임은 클라우드 컴퓨팅 기술을 네트워크 엣지에 더 가깝게 하며 서비스 지연 시간을 줄이기 위해서는 네트워크 엣지에 있는 여러 Edge Cloud에서 서비스 호스팅된다. 모바일 사용자의 경우 서비스 품질 유지를 위해 서비스를 가장 적합한 Edge Cloud로 마이그레이션하는 것은 중요하고 고이동성 시나리오에서는 서비스 마이그레이션 문제가 더욱 복잡해진다. 고정 이동 경로에서 사용자 이동성과 Edge Cloud 선택에 대한 어떤 영향을 미치는 건지 관찰하는 것이 이 연구의 목표다. Mobility-Aware Service Migration (MASM)은 고이동성 시나리오 동안 라우팅 비용과 서비스 마이그레이션 비용이라는 두 가지 주요 매개변수를 기반으로 서비스 마이그레이션을 최적화하기 위해 제안된다. 제안된 알고리즘을 기존의 그리디 알고리즘과 비교하여 평가한다.

• 한국통신학회논문지
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• 제31권1A호
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• pp.23-29
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• 2006

무선 센서네트워크(Sensor Network)에서는 많은 수의 센서 노드를 영구적으로 사용하기 보다는 일회성의 목적으로 사용하기 때문에 센서 네트워크를 구성하는 노드들의 수명을 장시간 유지시키는 것이 매우 중요하다. 이를 위해서 본 논문에서는 무선 센서네트워크의 연결 유지 시간(network lifetime)을 연장시키기 위한 EASR(Energy Aware Source Routing) 프로토콜을 제안한다. 제안하는 EASR 기법은 기존의 EAR(Energy Aware Routing)처럼 다중 경로 중에 확률에 의해 결정되는 단일 경로로만 데이터 트래픽을 전송하여 에너지 소비를 분산시키는 방법을 사용한다. 하지만 제안하는 EASR 기법에서는 기존의 SMR(Split Multipath Routing)에서 사용되는 다중 경로 선정 기법을 개선한 방법으로서 센서 노드들의 에너지 소비를 최소화 하기 위하여 다중 경로간의 overhearing 지수를 정의하고 이를 근거로 overhearing 현상에 의한 에너지 소비를 최소로 하는 다중 경로를 설정하는 기법이다. 제안하는 EASR기법이 무선 센서네트워크 환경에서 노드의 수명을 장시간 유지시키고 합리적인 데이터 전송 지연시간을 갖는다는 것을 시뮬레이션 분석을 통해 확인하였다.

• Journal of information and communication convergence engineering
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• 제10권3호
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• pp.231-236
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• 2012

For real-time wireless sensor network applications, it is essential to provide different levels of quality of service (QoS) such as reliability, low latency, and fault-tolerant traffic control. To meet these requirements, an (m,k)-firm based real-time routing protocol has been proposed in our prior work, including a novel local transmission status indicator called local DBP (L_DBP). In this paper, a fault recovery scheme for (m,k)-firm real-time streams is proposed to improve the performance of our prior work, by contributing a delay-aware forwarding candidates selection algorithm for providing restricted redundancy of packets on multipath with bounded delay in case of transmission failure. Each node can utilize the evaluated stream DBP (G_DBP) and L_DBP values as well as the deadline information of packets to dynamically define the forwarding candidate set. Simulation results show that for real-time service, it is possible to achieve both reliability and timeliness in the fault recovery process, which consequently avoids dynamic failure and guarantees meeting the end-to-end QoS requirement.