Named Data Networking (NDN) is a promising architecture for the future Internet and it is mainly designed for efficient content delivery and retrieval. However, producer mobility support is one of the challenging problems of NDN. This paper proposes a scheme which aims to optimize the tunneling-based producer mobility solution in NDN. It does not require NDN routers to change their routing tables (Forwarding Information Base) after a producer moves. Instead, the Interest packet can be sent from a consumer to the moved producer using the tunnel. The piggybacked Data packet which is sent back to the consumer will trigger the consumer to send the following Interest packets through the optimized path to the producer. Moreover, a naming scheme is proposed so that the NDN caching function can be fully utilized. An analysis is carried out to evaluate the performance of the proposal. The results indicate that the proposed scheme reduces the network cost compared to related works and supports route optimization for enhanced producer mobility support in NDN.

A threshold secret sharing scheme protects content by dividing it into many pieces and distributing them among different servers. This scheme can also be utilized for the reliable delivery of important content. Thanks to this scheme, the receiver can still reconstruct the original content even if several pieces are lost during delivery due to a multiple-link failure. Nevertheless, the receiver cannot reconstruct the original content unless it receives pieces more than or equal to the threshold. This paper aims to obtain reliable delivery routes for the pieces, as this will minimize the probability that the receiver cannot reconstruct the original content. Although such a route optimization problem can be formulated using an integer linear programming (ILP) model, computation of globally optimum delivery routes based on the ILP model requires large amounts of computational resources. Thus, this paper proposes a lightweight method for computing suboptimum delivery routes. The proposed greedy method computes each of the delivery routes successively by using the conventional shortest route algorithm repeatedly. The link distances are adjusted iteratively on the basis of the given probability of failure on each link and they are utilized for the calculation of each shortest route. The results of a performance evaluation show that the proposed method can compute sub-optimum delivery routes efficiently thanks to the precise adjustment of the link distances, even in backbone networks on a real-world scale.

This paper presents an optimal cooperative routing protocol (OCRP) aiming to improve the in-network cache utilization of the Content-Centric Networking (CCN). The objective of OCRP is to selectively aggregate the multiple flows of interest messages onto the same path in order to improve the cache utilization while mitigating the cache contention of the Content Stores (CSs) of CCN routers on the routing path. The proposed routing protocol consists of three processes: (1) Prefix Popularity Observation; (2) Prefix Group (Un)Subscription; and (3) Forwarding Information Base (FIB) Reconstruction. Prefix Popularity Observation observes the popularly cited prefixes to activate a prefix group (un)subscription function, which lets the Designated Router (DR) know which requester router wants to either join or leave a prefix group. Prefix Group (Un)Subscription lets the DR know which requester router is demanding to join or leave which prefix group. FIB Reconstruction reconstructs the FIB entries of the CCN routers involved in the newly computed optimal cooperative path of all prefix groups. The optimal routing path is obtained by binary linear optimization under a flow conservation constraint, cache contention mitigating constraint, and path length constraint. Two metrics of server load and round-trip hop distance are used to measure the performance of the proposed routing protocol. Simulation results from various network scenarios and various settings show advantages over the shortest path routing and our previously proposed cooperative routing schemes.

The Internet Engineering Task Force (IETF) has been actively standardizing distributed mobility management (DMM) schemes with multiple Mobility Anchors (MAs). Yet, all existing schemes have limitations that preclude the efficient distribution of mobile data traffic, including single point failure problems, heavy tunneling overheads between MAs, and a restrictive traffic distribution for external nodes in a mobility domain. Therefore, this paper proposes an efficient mobility management scheme with a virtual Local Mobility Anchor (vLMA). While the vLMA is designed assuming multiple replicated LMAs for a PMIPv6 domain, it acts virtually as a single LMA for the internal and external nodes in the PMIPv6 domain. Furthermore, the vLMA distributes mobile data traffic using replicated LMAs, and routes packets via a replicated LMA on the optimal routing path. Performance evaluations confirm that the proposed scheme can distribute mobile data traffic more efficiently and reduce the end-to-end packet delay than the Distributed Local Mobility Anchor (DLMA) and the Proxy Mobile IPv6 (PMIPv6).

PMIPv6 is the IETF standard for a network-based localized mobility management protocol. In PMIPv6, MNs are topologically anchored at an LMA, which forwards all data for registered MNs. However, since all data packets destined for MNs always traverse the MNs' LMA, the end-to-end packet delay is increased. Therefore, this paper proposes an RO scheme in single and multiple LMA environments. For efficient RO possibility detection, an IPv6 RO extension header and initial RO procedure are proposed. Plus, an effective post-handover RO procedure is presented, along with a packet forwarding scheme to avoid the race condition problem during an RO operation. A Performance evaluation confirms that the proposed scheme can significantly reduce the end-to-end delay, signaling overhead, and RO latency when compared with existing RO schemes.

In PMIPv6, all packets sent by mobile nodes or correspondent nodes are transferred through the local mobility anchor. This unnecessary detour results in high delivery latency and significant processing cost. Several PMIPv6 route optimization schemes have been proposed to solve this issue. However, they also suffer from the high signaling costs when determining the optimized path. The proposed scheme which adopts the prediction algorithm in PFMIPv6 can reduce the signaling costs of the previous schemes. Analytical performance evaluation is performed to show the effectiveness of the proposed scheme.

Packet delivery in Proxy Mobile IPv6 (PMIPv6) relies on an anchor node called LMA. All packets sent by a source node reach a receiver node via LMA, even though the two nodes attach to the same MAG. In some scenarios, PMIPv6 results in high delivery latency and processing costs due to this unnecessary detour. To address this issue, several PMIPv6 route optimization schemes have been proposed. However, high signaling costs and excessive delays remain when handover is performed. For this reason, we propose an enhanced PMIPv6 route optimization (EPRO) scheme. In addition, we analyze the performance of the EPRO. Analytical results indicate that the EPRO outperforms previous schemes in terms of signaling overhead and handover latency.

Route optimization for network mobility is a key technique for providing a node in a mobile network (Mobile Network Node or MNN) with high quality broadband communications. Many schemes adding route optimization function to Network Mobility (NEMO) Basic Support protocol, the standardized network mobility management protocol from the IETF nemo working group, have already been proposed in recent years. One such scheme, a scheme using Hierarchical Mobile IPv6 (HMIPv6) aims to overcome micromobility management issues as well by applying a mechanism based on HMIPv6. The traditional scheme, however, suffers from a significant number of signaling messages as the number of MNNs and/or the number of their Correspondent Nodes (CNs) increase, because many messages notifying the MNNs' Home Agents (HAMNNs) and the CNs of the mobile network's movement are generated simultaneously each time the mobile network moves to the domain of another micromobility management router (Mobility Anchor Point or MAP). This paper proposes a scheme to overcome this problem. Our scheme reduces the number of signaling messages generated at the same time by managing the mobility of MNNs using multiple MAPs distributed within a network for load sharing. The results of simulation experiments show that our scheme works efficiently compared to the traditional scheme when a mobile network has many MNNs and/or these MNNs communicate with many CNs.

Mobile IP is a solution to support mobile nodes but it does not handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) [1] ensures session continuity for all the nodes in a MObile NETwork (MONET). Since the protocol is based on Mobile IP, it inherits from Mobile IP the same fundamental problem such as tunnel convergence, when it is used to support the multicast for NEMO. In this paper, we propose the multicast Route Optimization (RO) scheme in NEMO environments. We suppose that the Mobile Router (MR) has a multicast function and the Nested Mobile Router Information (NeMRI). The NeMRI is used to record a list of the CoAs of all the MRs located below. And it obtains information whether the MRs desire multicast services. Also, we adopt any RO scheme to handle pinball routing. Therefore, we achieve optimal routes for multicasting in NEMO. We also develop analytic models to evaluate the performance of our scheme. We show much lower multicast tree delay and cost in NEMO compared with other techniques such as Bi-directional Tunneling (BT), Remote Subscription (RS), and Mobile Multicast (MoM) based on the NBS protocol.

The capability of Hierarchical Mobile IP (HMIP) for intra-domain route optimization is impaired when it is combined with Network Mobility (NEMO) technology. Deviations from the optimum path, caused by traffic aggregation in the Mobility Anchor Point (MAP), can be observed within a hierarchical domain. The problem is particularly noticeable in domains that span the mesh network topology. The lack of intra-domain path optimization in multi-level Mobile IP (MIP) leads to inefficient use of network resources. A Proxy Mobility Anchor Point (PMAP) functionality is proposed in domain nodes to enable intra-domain path optimization in multi-level MIP. Numerical evaluation and simulations indicate that this proposal can improve routing efficiency and throughput. The solution can be especially rewarding in network architectures where access network is separated from global network by bottleneck links and where the majority of users accessing the network are mobile routers.

The IETF (Internet Engineering Task Force) has developed a Network Mobility (NEMO) basic support protocol by extending the operation of Mobile IPv6 to provide uninterrupted Internet connectivity to the communicating nodes of mobile networks. The protocol uses a mobile router (MR) in the mobile network to perform prefix scope binding updates with its home agent (HA) to establish a bi-directional tunnel between the HA and MR. This solution reduces location-update signaling by making network movements transparent to the mobile nodes behind the MR. However, delays in data delivery and higher overheads are likely to occur because of sub-optimal routing and multiple encapsulation of data packets. To resolve these problems, we propose a mobile router-assisted route optimization (MoRaRo) scheme for NEMO support. With MoRaRo, a mobile node performs route optimization with a correspondent node only once, at the beginning of a session. After that the MR performs route optimization on behalf of all active mobile nodes when the network moves. The virtue of this scheme is that it requires only slight modification of the implementation of the NEMO basic support protocol at local entities such as the MR and mobile nodes of the mobile network, leaving entities in the core or in other administrative domains untouched. MoRaRo enables a correspondent node to forward packets directly to the mobile network without any tunneling, thus reducing packet delay and encapsulation overheads in the core network. To enable the scheme to be evaluated, we present the results of both theoretical analysis and simulation.

This paper compared the approaches concerning the pinball routing problem that occurs in the nested network in network mobility environment and developed the analytic framework to model. Each model was evaluated of transmission latency, memory usage, and BU's occurrence number at routing optimization process. The estimation result showed that the optimization mechanism achievement overhead existed in each model, and the full optimization of the specific model was not attained because of it. Therefore, the most appropriate approach for routing optimization in nested NEMO can be determined only after a careful evaluation, and the proposals must consider using it in combination with other approaches. The modeling framework presented in this paper is intended to quantity the relative merits and demerits of the various approaches.

In the last few years we have seen an explosion in the number of notebook computers and in the growth of the Internet. Mobile users expect to access the Internet's information resources and to communicate with other Internet users. The concept of Mobile IP is proposed to satisfy these demands. Using the base Mobile IP protocol, all datagrams destined for a mobile node are routed through that mobile node's home agent, which intercepts and tunnels each datagram to the mobile node's current location. This tunneling scheme creates a triangle routing problem, causing packets to travel through the home agent. In this paper, we propose that a Proxy Home Router (PHR) for routing performance improvement in a Mobile IP environment. One or more of Intermediate Systems (IS) on the route path between the correspondent node (CN) and the home agent (HA) are established as a PHR which then delivers packet instead of the home agent (HA). This PHR route optimization (PHR-RO) scheme has the following features. It is compatible with the base Mobile IP with existing Internet computers, and applications. Also, it is unnecessary for a CN to be modified in the proposed architecture. We also define Route Optimization messages in order to optimize route to a mobile node. Using these protocol extensions, a PHR may cache the binding information of a mobile node, and then tunnel their datagrams for the mobile node (MN) directly to the care-of address (CoA), bypassing the mobile node's home agent (HA). To analyze the performance of our PHR route optimization (PHR-RO) scheme, we propose a simulation model and show how to improve routing performance. Through this performance analysis, we conclude that the route optimization with a proxy home router (PHR) has better performance in terms of the end-to-end delay and TCP throughput.

A new mobility management architecture is proposed to optimize end-to-end routes for mobile nodes (MNs) and mobile routers (MRs) within a nested mobile network environment. By applying local network mobility management mechanisms based on Hierarchical Mobile IPv6 (HMIPv6) to a mobile network, the proposed approach can optimize the route to the mobile network effectively. Combining the proposed route optimization methods and HMIPv6 functionality can enable it to provide more effective route optimization, reducing the burden of location registration for handovers. A route optimization method for local fixed nodes in a mobile network has also been developed by adding proxy mobile node and correspondent node functions to the MRs. Numerical evaluations on mean route length and traffic routed through network nodes demonstrate the effectiveness and applicability of the proposed methods especially in large-scale networks.

For ubiquitous computing and communication, a mobile node needs to change upon movements its network- and link-layer points of attachment to the Internet. Conventionally, the network-layer protocol is unaware of the link-layer changes, so IP datagrams to and from a moving node could be lost. Considerable system performance degradation might therefore result. This paper presents a scheme to integrate the handoff procedures of the two layers in the context of Mobile IP with route optimization. Experiment results show that our scheme is promising and can reduce packet loss due to host migrations substantially.

The IETF Mobile IPv6 enables any IPv6 node to both cache the Care-of Address associated with a mobile node's home address, and to directly send packets addressed to a mobile node at the Care-of Address using the IPv6 routing header. Support for optimizing the route is built in as a fundamental part of the protocol. Several hierarchical schemes have been presented recently on top of the Mobile IPv6. These schemes separate micro-mobility from macro-mobility and exploit a mobile node's locality. They can reduce the number of signaling messages sent to a home network and improve hand-off performance. However, existing hierarchical schemes do not achieve route optimization. When external correspondent nodes send packets to a mobile node, these packets are intercepted by an intermediate mobility agent encapsulated and routed to the mobile node. In this paper, we propose a new hierarchical scheme that enables any correspondent node to cache two Care-of Addresses; the mobile node's temporary address and the intermediate mobility agent's address. Also, we introduce two lifetimes managing the two Care-of Addresses. Until the lifetime associated with the mobile node's temporary address expires, a correspondent node can send packets directly to the mobile node. If the lifetime expires but the lifetime associated with the intermediate mobility agent's address has not expired, the correspondent node sends packets to the intermediate mobility agent. This proposal can reduce delay in packet delivery and optimize routing. Furthermore, based on the mobility of a mobile node, we introduce more reduced frequency of binding update and longer period of the lifetimes than the existing hierarchical schemes. Therefore, our proposal can reduce the binding update bandwidth as well as the packet delivery bandwidth lower than those of the IETF IPv6 and the existing hierarchical schemes.