이동 IPv6 망에서 신뢰성 있는 멀티캐스트 서비스를 지원하는 빠른 핸드오버 메커니즘

신석재,유상조,Shin Seok-Jae,Yoo Sang-Jo 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.9a

Mobile IPv6 환경에서 빠른 핸드오버 프로토콜은 핸드오버 과정에서 발생하는 지연 시간을 줄임으로써 끊김 없는 핸드오버가 가능하도록 해준다 본 논문에서는 이러한 빠른 핸드오버의 이점을 멀티캐스트 서비스에 효율적으로 적용할 수 있는 FMIP-M 메커니즘을 제안한다. FMIP-M 메커니즘은 Mobile IPv6 환경에서 신뢰성 있는 멀티캐스트 서비스를 지원하는 빠른 핸드오버 메커니즘으로, 호스트의 이동 시 기존의 멀티캐스트 서비스에 빠른 핸드오버 프로토콜을 적용했을 때 발생하는 데이터 손실 문제를 이전 AR를 통해 보상 받게 되므로 신뢰성 있는 데이터 전송을 할 수 있게 한다. 또한 멀티캐스트 서비스 경로의 변화에 따라 멀티캐스트 서비스를 받는 방법 선택을 동적으로 수행하여 전송 경로를 최적에 가깝게 설정함으로써 좀더 효율적인 멀티캐스트 서비스가 가능하도록 한다. 다양한 환경에서의 성능 모델 분석 결과를 통해 제안된 방법이 패킷 전송 비용 측면에서 우수한 성능을 보였다. Fast handover protocol provides seamless handover in mobile Ipv6 networks by reducing handover latency. This paper proposes FMIP-M mechanism to apply this advantage of fast handover protocol to multicast service. The FMIP-M is a fast handover mechanism that supports a reliable multicast service in mobile Ipv6 networks. When hosts move other networks, they may have seine data missing and out-of-synch problems of multicast data. The proposed mechanism provides reliable multicast transmission by compensating data losses from the previous AR. Also it provides an additional function that is able to change multicasting service types dynamically in accordance with network status related with multicasting. So that it is able to make multicast paths very close to the optimum and more efficient multicast service is possible. The performance of the proposed mechanism is evaluated by a time analysis and simulations in various conditions.

WiMAX 망에서 계층적 비디오 멀티캐스트를 위한 적응적 변조 및 코딩의 적용

한민규(Minkyu Han),홍진표(Jinpyo Hong) 한국정보과학회 2011 정보과학회 컴퓨팅의 실제 논문지 Vol.17 No.2

WiMAX는 기본적으로 7가지의 적응적 변조 및 코딩 레벨을 제공하고 있다. 일반적으로, 높은 비트율로 변조, 코딩 된다면 전파 도달범위가 적어서 수신자의 수는 줄어들게 되고, 반대로 낮은 비트율로 전송된다면 전파 도달범위가 커져서 이를 수신할 수 있는 수신자 수는 증가하게된다. WiMAX의 MBS(Multicast and Broadcast Service)는 서비스가입자 그룹에게 멀티미디어 데이터를 전송하기위해, 일대다 접근 서비스를 제공한다. WiMAX 표준에 따르면, 유니캐스팅에서는 적응적 변조 및 코딩을 적용할 수 있으나, 멀티캐스팅에서는 하나의 변조 및 코딩 방식만 채택하는 것으로 되어 있다. 한편, H.264/SVC (Scalable Video Coding), MPEG-2등 계위적 비디오는 계층적 멀티캐스팅(Layered Multicasting)이 가능하기 때문에 수신자는 네트워크 혼잡이나 수신기 해상도에 따라 비디오 계층을 선택적으로 수신할 수 있다. 본 논문은 비디오 계층에 대해 송신할 때 변조 및 코딩 레벨을 달리 적용하여 계층적 멀티캐스팅을 하는 방식을 제안한다. 다양한 전파 지연모델을 활용하고 WiMAX 환경변수를 가정하여 변조 및 코딩방식에 따라 전파 도달범위를 계산하고, 수신자가 균일하게 분포된다고 가정할 때, 계층이 없고 QPSK 1/2로 변조 및 코딩방식을 동일하게 적용하는 표준 WiMAX 멀티캐스트에 비해 수신율을 향상시킬 수 있음을 보인다. Basically, WiMAX supports the seven levels of adaptive modulation and coding In general, if a system communicates with a high bitrate modulation and coding, the number of users may be decreasing due to the small coverage of radio signals. Otherwise, if the system transmits a low bitrate, the number of users may be increasing because of the fact that the coverage will be expanded. In order to transmit multimedia data to group of subscribers, the MBS mechanism of WiMAX provides one-to-many service for users likely multicasting services. According to the WiMAX standard, we can apply to adaptive modulation and coding in unicasting, but it’s supposed to adapt for only one modulation and coding in multicasting. On the other hand, The scalable layered video (i.e., H.264/SVC, MPEG-2) is enable to layered multicasting, so subscribers will be received selective video layers based on information of network congestion, the resolution of receiver’s devices and so on. In this paper, we propose a layered multicasting to apply for different modulation and coding for layered video streaming at base station of WiMAX networks. We assume that there are the various radio propagation models and the users are uniformly located themselves, the system transmits a video layer and it demonstrates the increase of received data rate over non-layered video streaming and only QPSK 1/2 modulation and coding.

묵시적 응답 및 간접 복구를 이용한 무선 센서 네트워크에서의 신뢰성 있는 멀티캐스팅

김성훈(Sung Hoon Kim),양현(Yang Hyun),박창윤(Chang Yun Park) 한국정보과학회 2008 정보과학회논문지 : 정보통신 Vol.35 No.3

센서네트워크가 다양하고 동적인 영역으로 발전해감에 따라 임무 갱신과 같은 기능을 위해 신뢰성 있는 멀티캐스팅 기술이 새롭게 요구되고 있다. 기존의 연구들은 NAK 기반 방식을 사용하고 있지만, 마지막 패킷 문제 등을 안고 있다. 본 논문은 묵시적 ACK와 간접 복구를 이용하는 ACK 기반 오류제어 기법인 RM2I를 제안한다. 묵시적 ACK는, 송신 노드로부터 패킷을 받은 수신 노드가 다음 노드로 포워딩할 때 송신 노드도 이를 간접적으로 받게 되는데, 이 수신 내용을 ACK로 해석하는 것을 말한다. 간접 복구는 어떤 노드가 상위 노드가 아닌 이웃노드로부터 패킷을 간접적으로 받았을 때 이를 상위 노드로부터 받은 것으로 해석하여 오류 복구에 활용하는 것을 말한다. NS-2 시뮬레이터를 이용하여 다양한 환경 및 인자에서 RM2I의 에너지 성능을 분석 및 검증하였다. 실험 결과, 묵시적 ACK는 ACK의 수를 줄여 제어 부하를 감소시키고, 간접 복구는 재전송 횟수를 줄여 데이타 전송 부하를 감소시켰다. 또한, NAK 기반 오류 복구 기법의 이론적 에너지 성능 상한선을 계산하여 이와 비교하였다. 비교 결과, 에지 노드에서의 부하를 제외하면 어떤 NAK 기반 기법과도 견줄 수 있는 에너지 효율성을 제공한다는 것을 알 수 있었다. As sensor networks are used in various and dynamic applications, the function of sink-to-sensors reliable multicasting such as for task reprogramming is newly required. NAK-based error recovery schemes have been proposed for energy efficient reliable multicasting. However, these schemes have incompleteness problems such as the last packet loss. This paper introduces an ACK-based error recovery scheme, RM2I(Reliable Multicast with Implicit ACK and Indirect Recovery). It utilizes wireless multicast advantage in which a packet may be delivered to all of its omni-directional neighbor nodes. When a sender overhears a packet which its receiver forwards to the next nodes, it may interpret it as an ACK from the receiver. We call it an Implicit ACK. In Indirect Recovery, when a node receives a packet from neighbor nodes which are not its direct upstream node, it saves and utilizes it for error recovery. Using NS-2 simulator, we have analyzed their effects. We have also compared RM2I with the NAK-based error recovery scheme. In results, RM2I shows comparable performances to the ideal NAK-based scheme, except where Implicit ACK and Indirect Recovery do not occur at the edges of the networks.

On the Heterogeneous Postal Delivery Model for Multicasting

Sekharan, Chandra N.,Banik, Shankar M.,Radhakrishnan, Sridhar The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.5

The heterogeneous postal delivery model assumes that each intermediate node in the multicasting tree incurs a constant switching time for each message that is sent. We have proposed a new model where we assume a more generalized switching time at intermediate nodes. In our model, a child node v of a parent u has a switching delay vector, where the ith element of the vector indicates the switching delay incurred by u for sending the message to v after sending the message to i-1 other children of u. Given a multicast tree and switching delay vectors at each non-root node 5 in the tree, we provide an O(n$^{\frac{5}{2}}$) optimal algorithm that will decide the order in which the internal (non-leaf) nodes have to send the multicast message to its children in order to minimize the maximum end-to-end delay due to multicasting. We also show an important lower bound result that optimal multicast switching delay problem is as hard as min-max matching problem on weighted bipartite graphs and hence O(n$^{\frac{5}{2}}$) running time is tight.

On the Heterogeneous Postal Delivery Model for Multicasting

Chandra N. Sekharan,Shankar M. Banik,Sridhar Radhakrishnan 한국통신학회 2011 Journal of communications and networks Vol.13 No.5

The heterogeneous postal delivery model assumes that each intermediate node in the multicasting tree incurs a constant switching time for each message that is sent. We have proposed a new model where we assume a more generalized switching time at intermediate nodes. In our model, a child node v of a parent u has a switching delay vector, where the ith element of the vector indicates the switching delay incurred by u for sending the message to v after sending the message to i − 1 other children of u. Given a multicast tree and switching delay vectors at each non-root node in the tree, we provide an O(n 52 ) optimal algorithm that will decide the order in which the internal (non-leaf) nodes have to send the multicast message to its children in order to minimize the maximum end-to-end delay due to multicasting. We also show an important lower bound result that optimal multicast switching delay problem is as hard as min-max matching problem on weighted bipartite graphs and hence O(n 52 ) running time is tight.

프록시 모바일 IPv6 네트워크에서 멀티캐스팅기반 빠른 이동성관리 기법의 분석적 접근법

김영훈 ( Kim Young Hoon ),정종필 ( Jeong Jong Pil ) 한국인터넷정보학회 2013 인터넷정보학회논문지 Vol.14 No.3

무선 네트워크에서 효율적인 이동성관리는 모바일 사용자의 지원에 상당히 중요하다. 몇몇의 이동성관리 기법들은 MN(Mobile Node)의 시그널링 트래픽을 줄여주는 목적으로 제안되었다. 그 중에서 PMIPv6(Proxy Mobile IPv6)는 호스트 기반의 이동성관리 프로토콜과 유사하지만 MN에게 이동성에 대한 어떠한 처리도 요구하지 않는다. MAG(Mobile Access Gateway)와 LMA(Local Mobility Anchor)같은 새로운 모바일 에이전트를 도입하여 MN에게 IP 이동성을 제공한다. 본 논문에서, MN 이동성의 종류에 따라 호출 당 평균 시그널링 지연과 평균 대역폭을 평가하는 분석 모델을 제안한다. 수학적 분석의 결과로 MF-PMIP(Multicasting-based FastPMIP)는 거의 모든 성능평가 매개변수에 대하여 D-PMIP에 비해 우수한 성능을 보여준다. In wireless networks, efficient mobility management to support of mobile users is very important. Several mobility management schemeshave been proposed with the aim of reducing the signaling traffic of MN(Mobile Node). Among them, PMIPv6 (Proxy Mobile IPv6) is similar with host-based mobility management protocols but MN does not require any process for mobility. By introducing new mobile agent like MAG (Mobile Access Gateway) and LMA (Local Mobility Anchor), it provides IP mobility to MN. In this paper, we propose the analytical model to evaluate the mean signalingdelay and the mean bandwidth according to the type of MN mobility. As a result of mathematical analysis, MF-PMIP (Multicasting-based FastPMIP) outperforms compared to F-PMIP and PMIP in terms of parameters for the performance evaluation.

MMS와 디지털 공익성

정인숙(In-Sook Jung) 한국여성커뮤니케이션학회 2007 미디어, 젠더 & 문화 Vol.8 No.-

지상파 방송 사업자들이 추진하고 있는 MMS는 향후 지상파 방송의 위상은 물론 유료방송과의 관계 설정에도 영향을 미칠 수 있으며, 향후 방송시장구조를 좌우할 수 있는 중요한 디지털 정책이슈이다. 이 논문은 MMS 도입에 대해 찬반 논쟁을 벌이고 있는 관련 주체들이 주장의 논거로 삼고 있는 공익성의 스펙트럼을 분석했다. 지상파 방송 사업자, 케이블TV 방송 사업자, 시민단체, 소비자집단의 공익 논거를 분석한 결과 MMS 도입을 찬성하는 지상파 방송 사업자와 시민단체는 공동체지향적 공익에 근거하고 있으며, MMS 도입을 반대하는 케이블TV 사업자와 소비자단체는 각자의 선택성을 강조하는 시장지향적 공익성을 강조하고 있는 것으로 나타났다. 공동체지향적 공익이란 공동체 이익, 사회적 약자에 대한 보호, 유료서비스에 대한 대안 등을 특징으로 하고 있으며, 시장지향적 공익이란 사업자와 소비자의 경제적 이익, 공정 경쟁 등을 주요 요소로 하고 있다. 결국 MMS 정책은 이와 같은 디지털 공익성의 대립을 어떻게 조화시키고 방송정책 이념적 목표를 어떻게 설정하느냐의 문제로 귀결된다고 할 수 있다. This paper traces the double conflicts of multicasting among Korean broadcasting policyplayers - broadcasters vs cable operators and citizen groups vs consumer groups. Multicasting is the technology to allow broadcasters to split their digital television signal into multiple streams. It enhance program options for viewers and encourage broadcasters to create more contents. But the cable operators do not agree to the introduction of multicasting. They're worried that the free multicasting content might compete with the cable networks they own themselves and strengthens the monopoly power of terrestrial broadcasters. So Korean cable companies succeed in blocking the introduction of service as other countries. Recently, in addition to the struggles between the broadcasters and cable operators, new controversy between the citizen groups is unfolding in Korea. While some citizen groups come out on the side of the terrestrial broadcaster, the other consumer group which have already bought HDTV set to watch the high definition TV, strongly opposes the multi-channel service. They insist that they can't give up the vested right of choice of high quality TV. Here, interesting point is that four players are all commonly insisting their assertions based on the logic of public interest. Their public interest discussions are divided into two categories; community-oriented and market-oriented KBC(Korean Broadcasting Commission), the government agency that regulates the broadcasting industry, is faced with a difficult situation to decide new policy paradigm or direction about digital public interest.

Multicast-based Broadcasting Service Adaptive to Zapping Pattern

Kang-Woon Hong,Seng-Kyoun Jo,Won Ryu 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

A channel zapping time in a cable broadcasting service is similar to one in a terrestrial broadcasting service because data for all channels reach a subscriber’s television. However, data for just a few channels will seriously waste a bandwidth of a communication network if a broadcasting service is implemented following the data transport scheme in the existing broadcasting service. While a multicasting scheme utilizes the bandwidth in an economical way, it results in a long latency for the channel zapping. In this paper, we propose a multicast forwarding scheme to reduce a channel zapping time as well as to utilize a network bandwidth efficiently.

An Efficient Multicast-based Binding Update Scheme for Network Mobility

Kim, Moon-Seong,Radha, Hayder,Lee, Jin-Young,Choo, Hyun-Seung Korean Society for Internet Information 2008 KSII Transactions on Internet and Information Syst Vol.2 No.1

Mobile IP (MIP) is the solution supporting the mobility of Mobile Nodes (MNs), however, it is known to lack the support for NEtwork MObility (NEMO). NEMO manages situations when an entire network, composed of one or more subnets, dynamically changes its point of attachment to the Internet. NEMO Basic Support (NBS) protocol ensures session continuity for all the nodes in a mobile network, however, there exists a serious pinball routing problem. To overcome this weakness, there are many Route Optimization (RO) solutions such as Bi-directional Tunneling (BT) mechanism, Aggregation and Surrogate (A&S) mechanism, Recursive Approach, etc. The A&S RO mechanism is known to outperform the other RO mechanisms, except for the Binding Update (BU) cost. Although Improved Prefix Delegation (IPD) reduces the cost problem of Prefix Delegation (PD), a well-known A&S protocol, the BU cost problem still presents, especially when a large number of Mobile Routers (MRs) and MNs exist in the environment such as train, bus, ship, or aircraft. In this paper, a solution to reduce the cost of delivering the BU messages is proposed using a multicast mechanism instead of unicasting such as the traditional BU of the RO. The performance of the proposed multicast-based BU scheme is examined with an analytical model which shows that the BU cost enhancement is up to 32.9% over IPDbased, hence, it is feasible to predict that the proposed scheme could benefit in other NEMO RO protocols.

An Efficient Multicast-based Binding Update Scheme for Network Mobility

( Moonseong Kim ),( Hayder Radha ),( Jin Young Lee ),( Hyunseung Choo ) 한국인터넷정보학회 2008 KSII Transactions on Internet and Information Syst Vol.2 No.1

Mobile IP (MIP) is the solution supporting the mobility of Mobile Nodes (MNs), however, it is known to lack the support for NEtwork MObility (NEMO). NEMO manages situations when an entire network, composed of one or more subnets, dynamically changes its point of attachment to the Internet. NEMO Basic Support (NBS) protocol ensures session continuity for all the nodes in a mobile network, however, there exists a serious pinball routing problem. To overcome this weakness, there are many Route Optimization (RO) solutions such as Bi-directional Tunneling (BT) mechanism, Aggregation and Surrogate (A&S) mechanism, Recursive Approach, etc. The A&S RO mechanism is known to outperform the other RO mechanisms, except for the Binding Update (BU) cost. Although Improved Prefix Delegation (IPD) reduces the cost problem of Prefix Delegation (PD), a well-known A&S protocol, the BU cost problem still presents, especially when a large number of Mobile Routers (MRs) and MNs exist in the environment such as train, bus, ship, or aircraft. In this paper, a solution to reduce the cost of delivering the BU messages is proposed using a multicast mechanism instead of unicasting such as the traditional BU of the RO. The performance of the proposed multicast-based BU scheme is examined with an analytical model which shows that the BU cost enhancement is up to 32.9% over IPDbased, hence, it is feasible to predict that the proposed scheme could benefit in other NEMO RO protocols.