Earticle

Distributed mobility management (DMM) is currently being researched and standardized in academia and standardization development organizations for the purpose of overcoming the major issues of existing centralized mobility management. The most recent DMM protocols are being redesigned with regard to the control and data plane separation concept. However, at present, there is no solution for supporting IP multicast listeners in such new DMM environments. In this paper, we review ongoing academic research works, standardization activities and propose an IP multicast mobility design for the DMM environment using the control and data plane concept.

The urban aerial mobility (UAM) system, such as drone taxi or air taxi, is one of future on-demand transportation networks. Among them, electric vertical takeoff and landing (eVTOL) is one of UAM systems that is for identifying the locations of passengers, flying to the positions where the passengers are located, loading the passengers, and delivering the passengers to their destinations. In this paper, we propose a distributed deep reinforcement learning where the agents are formulated as eVTOL vehicles that can compute the optimal passenger transportation routes under the consideration of passenger behaviors, collisions among eVTOL, and eVTOL battery status.

The advent multimedia real time application demands large volume of data to execute the required quality of service (QoS). Existing centralized approach lacks support its suitability in terms of dynamic mobility, scalability, reliability, seamless connectivity, etc. This motivates host based dynamic and distributed mobility management (DMM) solution for MIPv6 protocol to execute an intelligent mobility operation at an access network level rather centralized. The presented fully DMM architecture (FDMM) is implemented for integrated WLAN and WiMAX networks, where the entire mobility functions are distributed at access level in order to achieve a fast exchange of signaling information during handover operation. In addition, IEEE 802.21 media independent handover (MIH) standard is also adopted in the proposed work to execute seamless handover procedures across a heterogeneous background. The performance analysis of MIH-FDMM is compared with existing centralized mobility management (CMM) scheme in terms of handover delay, throughput, packet loss, etc. for real time traffic classes (constant and variable bit rate (CVBR)). Simulation result proves that the combined MIH-FDMM significantly minimize the handover delay, packet loss ratio and thus accomplishes seamless service for both real time and non-real time QoS efficiency.

A mobility management issue is surfacing again as it is expected that mobility requirements will be very essential and vary with application scenarios in the future 5G networks. An important research direction on this area is to design a flat and distributed control architecture to achieve scalability enough to be applied into the wide-scale real networks. In this paper, we propose a distributed mobility management framework for evolving networks toward 5G. The main idea is to separate location management from data traffic control during handling a node's handover. By being divided from location update to be propagated throughout whole network, handover control process can be localized and accelerated in a distributed manner. To apply different control operations according to handover types is another important feature of our approach. Experimental results from our simulation study show that the proposed framework considerably outperforms a well-known MM protocol, Proxy Mobile IPv6, in the aspects of handover latency, packet loss and dispersion of control overhead.

Most existing mobility management deployments such as MIPv6, PMIPv6 and 3GPP utilize centralized mobility anchors in the hierarchical network architecture. Centralized mobility schemes are subject to restrictions on reliability of SPOF (Single Point Of Failure) and network scalability, etc. As an alternative to the centralized approaches, DMM (Distributed Mobility Management) mechanisms have been actively and widely studied these days. In DMM, functions of the anchor node are efficiently distributed to access routers. This paper suggests the network-based partially distributed mobility management mechanism and performs extensive simulations under various traffic environments for verification and evaluation of the suggested scheme. Performance indexes such as Tx/Rx UDP traffic, end-to-end data transfer delay, binding delay, CPU utilization, WLAN throughput are analyzed and compared among MIPv6, PMIPv6 and the suggested DMM scheme. Simulation results show that the DMM scheme suggested in this paper is useful for IP mobility management research in wireless environment.

This paper provides the implementation mechanism of the pmipv6-based partially distributed mobility management (DMM) and performs extensive simulations under various traffic environments for verification and evaluation of the proposed scheme. The simulation results indicated that Mobility Anchor and Access Router (MAAR) could distribute and manage all IP data packet flow between a corresponding node (CN) and mobile node (MN). Therefore, the implementation and performance analysis of proposed mechanism is essential to understand the fundamental features of DMM, which includes a method of detecting MN and managing MN’s location.

In MANET, establishes the network no depends on the infrastructure and communicates. The topology is exchanged following the various conditions. Also the routing path is disconnected due to node mobility and direction of node. To solve these problems, we proposed the Load Tolerance Density-distribution (LTD) algorithm on dynamic density in mobile ad hoc networks. The proposed algorithm measures the dynamic density and load balance then it calculates the relationship between the cluster head nodes by the homogenous routing (passion) distributed procedure and provides the distributed routing path density in mobile ad hoc networks. In the simulation, we compare the LTD algorithm and the WCA algorithm and the Max-min algorithm. As the simulation results, the proposed algorithm improves the packet delivery ratio of various conditions in the clustering routing.

과부하 및 단일장애점(Single Point of Failure), 경로 비최적화, 망 확장성 등의 문제점을 가지고 있는 기존 중앙 집중형 이동성 관리 프로토콜들의 문제점을 해결하기 위해 최근 IETF를 중심으로 분산 이동성 관리 방안이 활발히 연구되고 있다. 본 논문에서는 망기반 부분분산형 이동성 관리 메커니즘 pDMMv6를 제시하고, 시뮬레이션을 통해 다양한 사용자 트래픽 환경에서 기존의 PMIPv6 및 MIPv6 프로토콜과의 성능 비교를 수행하였다. 성능분석 결과로는 UDP 트래픽의 전송율, 단대단 패킷 전송지연시간, 신호 메시지 바인딩 지연시간, 노드별 CPU 점유율 및 다양한 서버-클라이언트 TCP 응용에 따른 응답시간(웹 브라우징, 이메일 송수신, 텔넷 원격접속, FTP 파일전송, 데이터베이스 액세스 등)들을 제시하였다.

In order to solve the problems such as overload, single point of failure, non-optimized data path, and network scalability in conventional central mobility management protocols, distributed mobility management schemes have been continually studied in and around the IETF. In this paper, a network-based partially-distributed mobility management mechanism, pDMMv6, is suggested and the performance comparison with traditional protocols such as PMIPv6 and MIPv6 is made through simulation under the various user traffic environment. The simulation results include UDP packet delivery ratio, end-to-end packet delay, binding delay for registration signaling, CPU utilization in each node, and response delays in several server-client TCP applications such as web browsing, e-mail, telnet remote login, FTP file up/down-load, and database access.

한정된 자원으로 인해 개발이 더디게 진행되어오던 무선 센서 네트워크(Wireless Sensor Network)가 하드웨어 및 전원관리 기술의 발달로 인해 최근 IP를 기반으로 하는 IP-WSN으로 개발되고 있다. 그 방안으로 저 전력 장치에 IPv6를 탑재할 수 있는 6LoWPAN (IPv6 over Low power WPAN)이 주목받고 있다. 이런 IP 기반의 센서 네트워크에서는 기존 무선 센서 네트워크에서는 불가능하던 IP 기반의 기법들이 가능해진다. 6LoWPAN은 IEEE 802.15.4를 기반으로 하는 센서 네트워크에 IPv6를 지원하기 위한 기술이다. 호스트 기반의 이동성 관리 기법은 IP-WSN 에 부가적인 시그널링으로 인해 적합하지 않고, 네트워크 기반의 이동성 관리 기법이 적합하다. 따라서 본 논문에서는 다중 6LoWPAN 네트워크 환경을 고려한 PMIPv6 기반의 향상된 경로 최적화 방안을 제안한다. 6LoWPAN 도메인의 모든 SLMA(Sensor Local Mobility Anchor)는 SPIG(Sensor Proxy Internetworking Gateway)에 연결되어 6LoWPAN도메인 간 분산 이동성 제어를 수행한다. 6LoWPAN 도메인 내 모든 SLMA의 정보를 SMAG(Sensor Mobile Access Gateway)가 유지하도록 하여 신속하게 경로 최적화를 수행하도록 하였으며, SLMA에 경로 최적화 상태 정보를 SPIG로부터 수신 받아 저장하여 추가적인 시그널링 없이 경로 최적화를 지원하도록 한다.

The development of wireless sensor networks (WSNs) is progressed slowly due to limited resources, but it is in progress to the development of the latest IP-based IP-WSN by the development of hardware and power management technology. IPv6 over Low power WPAN (6LoWPAN) is capable of IPv6-built low-power devices. In these IP-based WSNs, existing IP-based techniques which was impossible in WSNs becomes possible. 6LoWPAN is based on the IEEE 802.15.4 sensor networks and is a IPv6-supported technology. Host-based mobility management scheme in IP-WSNs are not suitable due to the additional signaling, network-based mobility management scheme is more suitable. In this paper, we propose an enhanced PMIPv6-based route optimization scheme which consider multi-6LoWPAN network environments. All SLMA (Sensor Local Mobility Anchor) of the 6LoWPAN domain are connected with the SPIG (Sensor Proxy Internetworking Gateway) and performs distributed mobility control for the 6LoWPAN-based inter-domain operations. All information of SLMA in 6LoWPAN domain is maintained by SMAG (Sensor Mobile Access Gateway), and then is performed the route optimization quickly. The status information of the route optimization from SPIG is stored to SLMA and it is supported without additional signaling.

모바일 IP는 간단하고 확장 가능한 글로벌 이동성을 지원하지만 과도한 시그널링 트래픽과 긴 시그널링 지연을 야기한다. 그래서 MN(Mobile Node)의 홈 네트워크에 위치업데이트 횟수를 줄이기 위해서는 시그널링 지연을 줄일 필요가 있다. 본 논문에서는 시그널링 오버헤드가 균등하게 분산되도록 지역 네트워크의 경계에 동적인 이동성과 각 MN의 트래픽 부하에 따라 조정되는 PMIPv6(Proxy Mobile IPv6) 네트워크에서의 동적인 지역적 이동성관리 기법(dMMS)을 제안한다. 제안하는 분산된 네트워크 시스템에서 각 사용자는 최소한의 시그널링 트래픽에 맞춘 최적화된 시스템을 구성한다. 시그널링 비용 함수를 제안하기 위해서 새로운 이산적 분석 모델을 제안하고, MN의 이동성 및 패킷 도착 패턴을 분석한다. 위치업데이트와 패킷 전달 비용의 총 평균을 계산하고, 최적의 지역 네트워크의 크기를 결정하기 위한 알고리즘을 제안한다. 수학적 분석의 결과, 제안한 dMMS 기법은 전체 시그널링 비용을 줄이는 측면에서 우수한 성능을 보일 수 있는 네트워크 환경을 제시한다.

Mobile IP is a simple and scalable global mobility solution. However, it may cause excessive signaling traffic and long signaling delay. So MN (Mobile Node) to the home network in order to reduce the number of location update signaling is necessary to reduce the delay. In this paper, the signaling overhead to be distributed evenly on the boundary of the regional network, each MN's dynamic mobility and traffic load is adjusted according to the PMIPv6 (Proxy Mobile IPv6) networks in the proposed dynamic regional mobility management scheme (dMMS). Each user in a distributed network system that offers the least amount of signaling traffic is tailored to the optimized system configuration. Signaling cost function in order to propose a new discrete analytical model is proposed, MN's mobility and packet arrival patterns. Location update and packet delivery costs to calculate the total average, the optimized area to determine the size of the network is proposed. The results of mathematical analysis, the proposed technique dMMS in terms of reducing the cost of the entire signaling were found to be excellent performance.

The constrained application protocol (CoAP) can be used for remotely controlling various sensor devices in Internet of Things (IoT) networks. In CoAP, to support the handover of a mobile sensor device, service discovery and message transmission needs to be repeated, although doing so would increase the handover delay significantly. To address this limitation of CoAP, a centralized CoAP scheme has been proposed. However, it tends to result in performance degradation for an inter-domain handover case. In this letter, we propose a distributed CoAP handover scheme to support the inter-domain handover. In the proposed scheme, a distributed mobility agent (DMA) is used for managing the location of mobile sensors in a domain and performing handover control operations with its neighboring DMAs in a distributed manner. A performance comparison reveals that the proposed scheme offers a performance improvement of up to 29.5% in terms of the handover delay.

With the dramatic increase in mobile traffic in recent years, some of the limitations of mobility management frameworks have magnified. The current centralized mobility management (CMM) strategy has various problems, such as a suboptimal routing path, low scalability, signaling overhead, and a single point of failure. To overcome these weaknesses in the CMM strategy, the Internet Engineering Task Force has been discussing distributed mobility management (DMM) strategies. The fundamental concept of a DMM strategy is to distribute the mobility anchors closer to the users. While the distribution of mobility anchors results in low-cost traffic delivery, it increases the signaling cost. To reduce this higher signaling cost, we propose a new DMM strategy applying the pointer forwarding technique. The proposed strategy keeps the existing tunnels and extends the traffic path as much as possible. In this paper, we analyze the performance of the pointer forwarding-DMM strategy and discuss its pros and cons.

Distributed mobility management (DMM) does not use a centralized device. Its mobility functions are distributed among routers; therefore, the mobility services are not limited to the performance and reliability of specific mobility management equipment. The DMM scheme has been studied as a partially distributed architecture, which distributes only a packet delivery domain in combination with the software defined network (SDN) technology that separates the packet delivery and control areas. Particularly, a separated control area is advantageous in introducing a new service, thereby optimizing the network by recognizing the entire network situation and taking an optimal decision. The SDN-based mobility management scheme is studied as a method to optimize the packet delivery path whenever a mobile node moves; however, it results in excessive signaling processing cost. To reduce the high signaling cost, we propose a hybrid distributed mobility management method and analyze its performance mathematically.

스마트 폰을 중심으로 하는 이동단말들의 폭발적인 증가로 인해 모바일 데이터 트래픽 또한 기하 급수적으로 증가해 왔으며 이로 인해 발생되는 네트워크의 부하를 줄이면서 동시에 이동단말의 이동시에도 서비스 제공에 영향을 주지 않기 위한 여러 이동성 관리 방안들이 Internet Engineering Task Force (IETF) 및 Third Generation Partnership Project (3GPP)를 통해 제안되어 왔다. 최근에는 이동성 관리의 주체가 되는 네트워크 시스템들을 가능한 분산시킴으로써 네트워크의 확장성 및 신뢰성을 높이기 위한 노력들이 진행 중에 있다. IETF에서는 분산형 이동성 관리 방법으로 Distributed Mobility Management (DMM) 방식을 표준화 중에 있으며 세부적으로는 부분 분산형 방식과 완전 분산형 방식을 포함하고 있다. 본 논문에서는 Proxy Mobile IPv6 (PMIPv6) 기반의 네트워크를 대상으로 Neighbor Discovery Protocol (NDP)를 확장, 적용하는 완전 분산형 이동성 관리 방법 (FuDMM)을 제안하였으며, 기존 방식들과의 정성적 비교를 통해 FuDMM에 대한 성능 측면의 장단점을 분석하였다.

Explosive growth of smartphone-based mobile nodes has increased exponentially the mobile data traffic on the Internet. To reduce the traffic load on the network and to support the seamless mobility of the mobile nodes, the IETF and 3GPP have standardized a number of mobility management mechanisms. More recently, they are making an effort to find some schemes to distribute the networking systems that involve in the mobility management in order to assure the scalability and the reliability of the network. In IETF, DMM concept for the distributed mobility management on the Internet is being discussed. Specifically, the DMM can be classified into the partially distributed management and fully distributed management. In this paper, we propose a fully distributed mobility management scheme (FuDMM) on PMIPv6-based network by applying the extended NDP. We also present the performance of FuDMM using the comparative analysis with the existing ones.

스마트폰이 과거 수년 사이에 급격하게 확산됨에 따라 LTE망 운영자들은 많은 모바일 데이터 트래픽 용량에 대처하기 위해 노력하고 있다. 이러한 문제를 해결하기 위해, 본 논문에서는 LTE/EPC 네트워크에서 집중화된 제어 평면과 분산된 P-GW를 지원하는 새로운 SDN 기반 분산 이동성 관리기법을 제안한다. 네트워크 성능을 더욱 향상 시키기 위해, LTE 사용자들 사이에 교환되는 내부 트래픽을 위한 경로 최적화를 제안한다. 제안된 기법과 기존의 LTE/EPC 네트워크의 기법의 P-GW 데이터 처리 용량과 데이터 처리 수 측면에서 성능을 비교함으로써, 제안된 기법이 LTE/EPC 코어 네트워크의 확장성을 증가시키는 효율적인 방법임을 보여준다.

The tactical network has several different characteristics compared with commercial internet network such as hierarchical topology, dynamic topology changing and wireless link based connectivity. For considering IP mobility management in the tactical network, current mobility management using Mobile IP(MIP) is not suitable with some reasons such as non-optimal routing paths and single point of failure. Proxy Mobile IP(PMIP) which supporting network-based mobility in hierarchical manner can provide optimal routing path in the tactical network environment, but centralized anchor is still remained a threat to the stability of the tactical network which changes its topology dynamically. In this paper, we propose PMIP-based distributed mobility management for the tactical network environment. From our design, routing paths are always configured in optimized way, as well as path is recovered quickly when the mobility anchor of user is failed. From numerical analysis, comparing to other mobility scheme, result shows that the proposed scheme can reduce packet transmission cost and latency in tactical network model.

분산 이동성 관리 방식은 이동성 기능을 사용자와 가까이에 위치한 네트워크 경계로 분산시킨다. 이에 따라서 트래픽 전달 비용을 낮추고 패킷 전달 경로를 최적화할 수 있으며 확장성이 높은 장점을 갖는다. 하지만, 시그널링 메시지를 교환하기 위한 모바일 앵커의 개수가 증가하여 시그널링 비용이 증가하는 문제점을 갖는다. 그래서 지속시간이긴 세션에 대해서 높은 시그널링 비용을 감소시키는 하이브리드 분산 이동성 방식이 연구되었고 본 논문에서는 네트워크 이동성을 지원하는 환경으로 하이브리드 방식을 확장한다. 모바일 라우터는 차량에 장착되어 모바일 장치들과 함께 이동한다. 따라서 모바일 라우터에 대해서 고속 이동성 특성을 정의하여 이용하는 하이브리드 방식을 제안한다. 모바일 라우터의 이동성 특성에 따라서 모바일 앵커를 분산하여 할당하거나 혹은 특정한 모바일 앵커를 지정하여 할당한다. 본 논문은 네트워크 이동성을 지원하는 하이브리드 분산 이동성 관리 방식에 대해서 제안하고 성능을 수학적으로 분석하여 우수한 성능임을 보여준다.

In Distributed Mobility Management (DMM) protocol, the mobility functions are distributed to network edge closer to mobile users. DMM protocol has some advantages of low-cost traffic delivery, optimized routing path, high scalability. However, it needs many mobile anchors to exchange signaling messages and it results in a high signaling cost. Thus, previous works suggested the hybrid DMM protocol to reduce the high signaling cost for long-live sessions and this paper extends a hybrid scheme to the NEMO environment. The mobile routers are installed at vehicles and can move together with several mobile devices. So we can define the high-mobility property for mobile routers and suggest the hybrid scheme using this property. According to the high-mobility property of mobile routers, we can distribute the mobile anchors or allocate a centralized mobile anchor. In this paper, we mathematically analyze the performance of the proposed NEMO-enabled hybrid DMM protocol and show superior performance.

최근 급격히 증가한 모바일 기기로 인하여 발생되는 데이터/제어 트래픽은 LTE/EPC 네트워크에서 중앙에 과다한 트래픽 수용문제가 중요 이슈로 부각되고 있다. 기존의 Centralized Mobility Management(CMM) 기반의 LTE/EPC 네트워크에서 Mobility Anchor 역할을 수행하는 Packet Data Network Gateway (P-GW)에서는 데이터 트래픽 과부하가 발생한다. 또한 Distributed Mobility Management (DMM) 기반의 LTE/EPC 네트워크에서 분산된 Mobility Anchor 역할을 수행하는 PDN Edge Gateway (P-EGW)에서는 제어 트래픽의 과부하가 발생한다. 본 논문에서는 이러한 문제를 해결하기 위하여 CMM 기반과 DMM 기반을 결합한 새로운 Software Defined Network (SDN) 기반의 LTE/EPC 네트워크 이동성 관리 기법을 제안한다. 이를 위하여, P-EGW를 네트워크 내에 분산 배치하고 중앙에 P-GW를 배치한다. SDN 컨트롤러는 EPC의 역할도 수행하며 UE의 이동성에 따라 적절한 CMM 기법과 DMM 기법을 이용하도록 하는 기법을 제안한다. 또한, 제안하는 새로운 LTE/EPC 네트워크 구조와 기존의 CMM기반의 LTE/EPC 네트워크 구조, DMM 기반의 LTE/EPC 네트워크 구조를 핸드오버 지연시간과 데이터 전송시간 측면에서 성능 비교 분석을 한다.

현재의 중앙 집중형 이동성 관리 방식의 제약점들을 극복하기 위해서, IETF는 홈 에이전트의 이동성 기능을 사용자 가까이에 위치한 네트워크 경계 쪽으로 분산시키는 분산 이동성 관리 방식에 대해서 논의해왔다. 분산 이동성 관리 프로토콜은 트래픽 전달 비용이 낮고 확장성이 높다는 장점을 갖고 있다. 하지만, 시그널링 비용이 높고 주소관리가 복잡하다는 문제점을 보이고 있다. 특히 세션의 지속시간이 길고 빠르게 이동하는 사용자의 경우에는 이러한 문제점을 더욱 어렵게 만든다. 지속시간이 긴 세션에 대해서 높은 시그널링 비용을 감소시키기 위해서 우리는 하이브리드 분산 이동성 관리 방식을 제안하며, 이는 세션 지속 시간에 따라서 다른 이동성 앵커를 할당한다. 본 논문에서 우리는 제안한 하이브리드 분산 이동성 관리 방식에 대해서 성능을 분석하며 시그널링 비용 측면에서 우수한 성능임을 보여준다.

To overcome the limitations of the current Central Mobility Management (CMM) protocols, IETF has been discussing about the Distributed Mobility Management (DMM) protocols that the centralized mobility functions of Home Agents (HA) are distributed to network edges closer to mobile users. The DMM protocol has some advantages of low-cost traffic delivery and high scalability. However, it faces several problems such as a high signaling cost and a complex address management. Especially, users moving at a high speed and with long-live sessions can make these problems worse. To reduce the high signaling cost for long-live sessions, we propose a novel hybrid DMM protocol allocating different mobility anchors according to the session durations. In this paper, we analyze the performance of the proposed hybrid DMM protocol and show superior performance with respect to the signaling cost.

PMIPv6과 같은 현재의 중앙 집중형 이동성 제어 프로토콜들은 모든 제어 트래픽과 데이터 트래픽을 함께 처리하는 중앙 집중형 이동성 앵커(central mobility anchor)에 전적으로 기반하여 동작한다. 그러나, 이러한 중앙 집중형 이동성 제어 프로토콜들은 코어망으로 트래픽이 집중되는 현상이 발생될 수 있거나, 이러한 중앙 집중형 이동성 앵커의 장애 발생 시 서비스 제공 불능현상 등이 발생될 수 있는 심각한 문제점을 안고 있다. 따라서, 본 논문에서는 이러한 문제점들을 완화시키기 위해, 사용자 이동 지역성을 고려한 PMIPv6 기반의 분산형 이동성 제어 기법을 제안한다. 성능 분석 결과, 제안 기법은 PMIPv6 및 관련된 분산형 이동성 제어 기술인 S-PMIP과 비교해 볼 때, 총 이동성 제어 비용을 대폭 감소시킴과 동시에 이러한 문제점들을 상당부분 해소시킬 수 있음을 입증한다.

The current centralized mobility control protocols such as proxy mobile IPv6 (PMIPv6) are dependent on a central mobility anchor to process all control/data traffic. However, such centralized mobility control protocols have some drawbacks such as traffic concentration into the core network and serious service degradation in case of the failure of such a centralized mobility anchor, etc. In this paper, therefore, in order to alleviate these drawbacks, we propose a PMIPv6-based distributed mobility control scheme considering a user's movement locality. Performance evaluation results demonstrate that the proposed scheme has apparent potentials to alleviate serious drawbacks of S-PMIP, which is a closely-related distributed mobility control scheme, as well as PMIPv6, while reducing the total mobility control cost.