Cellular universal IP

To deal with increasing number of the mobile devices and real-time applications in the next generation wireless IPv6 networks, effective mobility management has become a critical problem. IETF proposed mobile IPv6 (MIPv6) and its fast handoff protocol (FMIPv6) to provide mobility management for this demand. In this paper, we propose a seamless handoff scheme, which reduces the handoff delay by using an advanced care-of address (CoA) provisioning and testing method, for real-time applications based on FMIPv6. In our proposal, collision-free CoA is proactively prepared and the time for CoA testing is removed from the FMIPv6 handoff delay to achieve seamless handoff. The simulation results show that our proposal outperforms the current schemes on the aspect of handover delay.

The current deployment of wireless mesh networks requires mobility management to track the current locations of mobile nodes around the network without service interruption. To do so, the Hierarchical Mobile IPv6 protocol has been chosen, which minimises the required signalling by introducing a new entity called the mobile anchor point to act as a local home agent for all visiting mobile nodes in a specific domain. It allows a mobile node to register its local/regional care-of addresses with a mobile anchor point by sending a local binding update message. However, the local binding update is quite sensitive; it modifies the routing to enable mobility in the wireless mesh networks. When a local binding update message is spoofed, an attacker can redirect traffic that is destined for legitimate mobile node either to itself or to another node. This situation leads to an increased risk of attacks. Therefore, this paper contributes to addressing this security issue based on wireless mesh networks by cryptography generation and verification of a mobile node’s local and regional care-of addresses, as well as the application of a novel method to verify the reachability of mobile node at claimed local care-of address. This is called the enhanced mobile anchor point registration protocol. The Scyther tool has been used to ensure the proposed protocol accuracy. Furthermore, the performance, in terms of the mobile anchor point registration delay and signalling overhead, is evaluated by using the OPNET modeller simulator.

Multiple access methods in a wireless network allow multiple nodes to share a set of available channels for data transmission. The nodes can either compete or cooperate with each other to access the channel(s) so that either an individual or a group objective can be achieved. Game theory, which is a mathematical tool developed to understand the interaction among rational entities, can be applied to model and to analyze individual or group behaviour of nodes for multiple access in wireless networks. Game theory also enables us to model the selfish/malicious behaviour of nodes, and subsequently design the punishment or defense mechanisms for robust multiple access in wireless networks. In addition, game models can provide distributed solutions to the multiple access problems, which are based on solid theoretical foundations. In this survey, we provide a comprehensive review of the game models (e.g., noncooperative/cooperative, static/dynamic, and complete/incomplete information) developed for different multiple access schemes (i.e., contention-free and contention-based random channel access) in wireless networks. We consider time-division multiple access (TDMA), frequency-division multiple access (FDMA), and code-division multiple access (CDMA), ALOHA, and carrier sense multiple access (CSMA)-based wireless networks. In addition, game models for multiple access in dynamic spectrum access-based cognitive radio networks are reviewed. The major findings from the game models used for these different access schemes are highlighted. To this end, several of the key open research directions are outlined.

In this paper, a new approach is proposed to reduce handoff operation in IEEE 802.16e network. Traditional mobile approaches, such as mobile IPv6 (MIPv6) and hierarchical MIPv6 (HMIPv6), can support smoothly handoff. These approach, ,unfortunately, suffer large handoff delay and packet lost in macro mobility for mobile users. With the aid of the partner node, DAD operation can be pre-executed by the partner node before the mobile node initialize the handoff request, we propose a cross-layer partner based fast handoff mechanism based on HMIPv6 in IEEE 802.16e network, called as P_HMIPv6 protocol. The P_HMIPv6 protocol is a cross-layer, layer 2 and layer 3, approach. The partner station (PS), which is a new component with relay ability and adopted by our protocol, is a static mobile station (MS). With the aid of the PSs, care-of address (CoA) can be pre-acquired and DAD operation can be pre-executed by the PS before the MS initials the layer 2 handoff. The simulation results show that P_HMIPv6 protocol actually achieves the performance improvements in the handoff delay time and the packet loss.

The purpose of this project is to increase the power quality by cancelling out the 
\ncurrent harmonic and voltage harmonic in transmission line which produced by non-linear loads. As a sequence, a series and shunt active harmonic filter is designed using 
\ntwo three phase inverters with sinusoidal pulsed-width modulation or SPWM switching-controlled. The three phase inverters function by changing the dc input voltage to a 
\nsymmetric ac output voltage. Then, the output is injected to the line to cancel out the 
\nexisting harmonic.The simulation is run using PSpice OrCAD 9.1 and the result showed 
\nthe total harmonic distortion of current (THDi) and voltage (THDv) are succesfully 
\ndecreased. At the end of the project, the prototype of active harmonic filter is developed. 
\nHowever, the prototype only capable to operate at low voltage and low current.

Hierarchical Mobile IPv6 (HMIPv6) has been proposed by the Internet Engineering Task Force (IETF) to reduce handoff latency and signaling overhead. In the new protocol, Mobility Anchor Point (MAP) receives all packets in place of Mobile Node (MN) and MAP services are transferred to Care of Address (CoA) of MN. However, a MAP may be a single point of performance bottleneck because the MAP should not only handle signaling traffic but also process data tunneling traffic for all MNs registered in a MAP domain. So, MAPs need MAP management scheme for the multimedia services or real time services. We propose a MAP selection scheme that can select different MAPs according to the traffic characteristics of MNs and a multilevel queue processing method that can process binding updates based on the priorities of queues in a MAP when MNs send BU. Quantitative results of the performance analysis show that our proposal can reduce the location update cost by 31% and the total cost by 14%. With the multilevel queues, we could reduce the total cost by 12% and 17% for D=4 and D=8 respectively.

Fast handover protocol provides seamless handover in mobile IPv6 networks by reducing handover latency. One assumption in fast handover is that the MN (Mobile Node) or the network could know or predict the new AR (Access Router) before data transport from the previous AR to the MN is disrupted. In order to achieve this capability, the complexity of predicting the new AR and the diversity of the wireless link technologies should be considered. While it is difficult to know or predict the new AR exactly, a better solution is required to find a reasonable set of candidate ARs (i.e., neighbor ARs) that are likely to be the new AR after a handover. This paper introduces a solution to support a fast handover mechanism using multi-tunnels between MAP (Mobility Anchor Point) and neighbor ARs in HMIPv6 (Hierarchical Mobile IPv6) network. It includes the concepts of Proxy Mobile IP for creation of CoA (Care of Address) and DAD (Duplicate Address Detection). In this protocol, the MN can handover without receiving any information about the new AR and this eliminates difficulties to know or predict exactly the new AR which is not specified in standard fast handover scheme. It decouples layer-2 and layer-3 handover and efficiently reduces handover latency through the minimized number of wireless signaling messages and pre-DAD. It also saves periods of service disruption and prevents packet loss in the case of ping-pong movement of the high-speed MN. The performance of the proposed mechanism is evaluated by simulations under variable conditions.

Wireless networks incorporate Mobile Nodes (MNs) that use wireless access networks to communicate. However, the communication among these MNs are not remained stable due to the poor network coverage during inter mobility. Moreover, the wireless nodes are typically small that results in resource-constrained. Thus, it is uphill to use algorithms having giant processing power or memory footprint. Accordingly, it is essential to check schemes consistently to evaluate the performance within the probable application scenario. To do so, numerical analysis could be a notable method to grasp the performance of mobility management schemes as well as the constraint of evolving mobility management solutions specifically for multi-interfaced MR in Proxy NEMO environment. This paper analyzes handoff performance by using a mathematical model of Multihoming-based scheme to support Mobility management in Proxy NEMO (MM-PNEMO) environment. Moreover, a comparative study has been made among the standard Network Mobility Basic Support Protocol (NEMO BSP), Proxy NEMO (PNEMO) and MM-PNEMO scheme respectively. The performance metrics estimated for these schemes are mainly handoff delay and packet loss. This paper also analysed the packet loss ratio and handoff gain as a function of cell radius, number of SMR and velocity respectively. It is apparent that, the MM-PNEMO scheme shows lower packet loss ratio (1%) compared to NEMO-BSP (11%) and P-NEMO (6%).

With the functionalities of obtaining new care-of-address (CoA) ahead and building tunnels for packet forwarding during handover, the fast handover scheme has better performance than Mobile IPv6. However, the handover performance is downgraded if mobile node (MN) cannot finish the handover preparation before the associated link is broken. In this paper, we propose an optimistic ready-tunneling (ORT) control scheme to resolve the aforementioned problems. In the proposed ORT scheme, new access router (NAR) can prepare for a new CoA and builds a tunnel for MN ahead when MN enters the domain of NAR. As a result, MN can switch to the new network domain smoothly because of early CoA acquisition and tunnel establishment during handover.

An enhanced fast handover with seamless mobility support for next-generation wireless networks

This paper addresses a new approach of IP/MPLS to provide QoS in radio access networks (RANs) that satisfies the diverse QoS requirements while efficiently utilizing network resources in the RANs. Two levels of service differentiation are denned, namely MPLS-level and DiffServ-level. At MPLS-level, separate label switched paths (LSPs) are established for control plane traffic and user plane traffic. At DiffServ-level, control plane traffic (network control and signaling) and real-time user plane traffic are mapped to DiffServ expedited forwarding (EF); non-real-time user plane traffic is mapped to DiffServ assured forwarding (AF). Combining QoS routing with dynamic resource allocation, simulation results show that this approach does provides a framework of QoS support in IP/MPLS-based radio access networks.

With increased popularity and pervasiveness, mobile networking has become a definite trend for future networks. Users strongly demand that the connectivity of ongoing services be retained while roaming across different points of attachment. Efficient handover schemes are essential to the aforementioned vision. However, there are time-consuming procedures in the process. Various research has been devoted to the acceleration of movement detection and registration. However, a time-consuming operation, i.e., duplicate-address detection (DAD), was overlooked by most studies. One novel scheme that features anycast technique is developed and presented in this paper. The proposed approach switches to anycast addressing during handover and switches back to normal unicast addressing after all required operations are completed. By switching to anycast addressing, a mobile node can continue the reception of packets from its corresponding node before its new care-of address is actually validated. Thus, transmission disruption can effectively be minimized. In addition, a simple but effective buffer-control scheme is designed to reduce possible packet loss and prevent the out-of-order problem. Analytical study reveals that improved performance can be guaranteed, as reflected in the simulation results.

This paper proposes a novel secure binding management protocol for mobile IPv6 networks for use in the implementation of routing optimization. The idea uses the public key of the home network of a mobile node to cryptographically generate the mobile node's home address and the associated private key to sign the mobile node's authentication requests. In addition, the proposed protocol performs reachability tests for both the home address and the care-of address. The proposed protocol offloads all expensive cryptographic operations from a mobile node to its home agent. The security of the protocol is informally analysed and an initially evaluation of its performance given.

Efficient hierarchical SIP mobility management for WiMAX networks

When an ad hoc network is connected to the Internet, it is important for the mobile nodes to detect available gateways providing access to the Internet. We discuss the problem of interworking and integration between the ad hoc and radio access networks. Furthermore, we propose a signalling mechanism to discover and select the optimum gateway when more than one gateway is available. A gateway is considered to be optimum if the path via this gateway provides better quality of service such as total path bandwidth or overall delay. An optimum gateway selection scheme should consider both the ad hoc and radio access networks to provide better QoS support. To achieve this selection, QoS information from both sides of the network needs to be communicated across the network. Further research is required to adapt the proposed mechanism to be applied for wireless sensor networks.