Omer Mahmoud

Macro mobility scheme in NEMO to support seamless handoff

In order for the mobile networks to stay connected to the Internet, Network Mobility (NEMO) is involved with the management of the different types of movements by mobile routers during rapid changes of the Point of Attachment (PoA). Accordingly to achieve seamless handoff with lower delay and packet loss in NEMO environment, it is very important to get better performance of mobility management protocol. As the main idea of Network Mobility Basic Support Protocol (NEMO BSP) is to create bi-directional tunnel between the Serving Mobile Routers (SMR) with its Home Agent (HA) and perform the handoff after complete layer 2 switching. Therefore, it should limit frequent registrations of Mobile Network Nodes (MNNs) with their HAs. Furthermore, creating bi-directional tunnel between MR and its HA for all communications makes sub-optimal problem, in which all the packets are tunneled and encapsulated via HA of the Serving MR. This increases handoff delay, packet loss and disconnections probability. To overcome handoff related problems, the Fast Hierarchical Mobile IPv6 (FHMIPv6) works as a solution for host mobility. However, in nested NEMO environment applying improved FHMIPv6 mechanism is a challenging task since consideration has to be given to both MR and its MNNs as well. This paper proposed macro mobility scheme in order to achieve seamless handoff through modification of signaling messages. Additionally, location update cost is calculated and compared with NEMO BSP via analytical approach. The analytical result shows that the location update cost for the proposed scheme is about 69 % less than that of NEMO-BSP.

An investigation of femtocell network synchronization

Currently, Femtocell technology emerged for cellular wireless networks, which has rapidly engrossed cellular industry. The principle of femtocell to the mobile operators is to reduce cost and improve signal quality in indoor coverage which is also considered a possible path to the fixed-mobile convergence (FMC) goal. Femtocell extends network coverage and delivers high-quality mobile services inside residential and business buildings through broadband network, i.e. ADSL. Femtocell access point (FAP) or home base station (HBS) intends to serve small number of users, i.e. 4 users and covers about 30 meter square similar to existing WiFi access points. However, femtocell introduces new challenges to the telecom industries in terms of handoff between femto and macrocells, interference management, localization and synchronization. Among all of these challenges, synchronization is considered corner stone for proper working for femtocell. The problematic issue in femtocell synchronization is that all the data and control traffics travel through IP broadband network. The IP broadband network is usually owned and managed by third party and not by the mobile operator, which is complicated the synchronization. Unsynchronized FAPs may cause harm interferences and wrong handover dictions. In this study we investigate and overview the current femtocell synchronization techniques and compare between them. Possible improvements and recommendation for each method is identified. Proposed schemes and indicated future research areas are also discussed.

Evaluation study of QoS-enabled AODV

Due to the dynamic nature of mobile ad-hoc networks (MANETs), there are many issues which need to be tackled. One of the areas for improvement is quality of service (QoS) routing. Various approaches and enhancements have been proposed including QoS-AODV. It is proposed to enhance one of the existing routing protocols for MANET namely AODV (ad-hoc on-demand distance vector). In QoS-AODV the original AODV is extended by adding necessary new fields including maximum delay extension and minimum bandwidth extension. Our work highlights the combination of both metrics: delay and bandwidth respectively. The main aim of this paper is to conduct evaluation study on QoS-AODV along with our proposed approach. NS-2 simulator is used in performing the simulation study in order to test its effectiveness. Various scenarios with different mobility parameters are taken into account in the simulations. Average latency, packet delivery ratio (PDR) and normalized overhead load are the selected evaluation metrics. Our experiments study the effect of number of mobile nodes, maximum node speed and traffic load as well as the impact of connectivity maintenance methods employed namely: HELLO messages and MAC layer feedback.

Multicast network security using quantum key distribution (QKD)

We reviewed the confidentiality and authentication for multi-party applications. A conceptual model of a secure multicast network has been presented by adding a quantum key distribution (QKD) network to its architecture. The model is divided into three phases, the first phase, QKD network generate secure keys to encrypt not only data but also authentication process. The second phase, authentication making sure that no one except the legitimate user receive the message and making sure that nobody except the legitimate sender writes or modifies it. In the last phase, Multicast network encrypt the data by secure key and send it to receivers. The proposed scheme amid to provide a secure end to end communication for multicast network.

Quality of Service over Heterogeneous Network with MPLS Backbone

Internet growth in recent years has encouraged many new applications to be provided for the end user. However, providing and maintaining high quality of service for these new applications is a challenging matter that is getting the attention of many many researchers nowadays. The QoS challenge is emanating from the diversity of these applications, in term of bandwidth requirements and high sensitivity to delay and delay variation. Three main architectures were proposed by IETF in an effort to make the IP QoS a reality. They are integrated services (Intserv), differentiated services (DiffServ) and multiprotocol label switching (MPLS). Sometimes perceived as competitor, these architectures are in fact complementary developments that approach the QoS challenge from different network perspectives. Thus these approaches can work together in a manner that provides a global QoS within Heterogeneous network. This paper aims to propose and discusses an improved admission control mechanism in order to achieve a global QoS in the HN Network. The proposed mechanism uses MPLS-TE tunnels at the core of Heterogeneous networks to maintain QoS for inter-domain flows and applications.

Implementation of SARG04 decoy state quantum key distribution

The experiment of decoy state QKD has been reported using commercial QKD system based on a standard bi-directional ‘Plug & Play’ set-up. By making simple modifications to a commercial quantum key distribution system, decoy state QKD allows us to achieve much better performance than QKD system without decoy state in terms of key generation rate and distance. One decoy state protocol has been implemented. The obtained results demonstrate an unconditionally secure key rate of 0.127 × 10–4 per pulse for a 10 km fiber length.

Mobility support in MPLS network

Multi Protocol Label Switching (MPLS) is a core networking Quality of service architecture that basically operates in between Layers 2 and 3 of the Open Systems Interconnection (OSI) model; for this reason, MPLS has been referred to as operating at Layer 2.5. MPLS provides its users a number of advantageous features for instance guarantee Quality of Service (QoS), failure protection,. MPLS networks along with Traffic engineering enable load balancing all over the network by explicitly mapping the traffics into TE tunnel that use pre-specified route, which may be not shorted path, MPLS protocol was developed without having mobility in mind. MPLS features and benefits could be extended to support Mobile Nodes. This paper presents study of handover in MPLS domain. It suggests utilizing Bandwidth Agent to coordinate and facilitate the handover. Two scenarios were considered hard handover and soft handover. Simulation result shows that soft handover lead to smooth transition with less delay and losses

Design of robust protocol to enhance QoS in mobile IPV6 environment

This Supporting Quality of service (QoS) in the Internet is considered as one of the main challenges that recently got the attention of many researchers. QoS is the ability of a network element (e.g. an application, a host or a router) to provide some level of assurance for consistent network data delivery. Mobile IPv6 protocol enables a mobile node to communicate with other nodes after changing its point of attachment from one IP subnet to another without changing its IP address. However it can only provide best-effort services to all its applications. The best-effort delivery works fine with the conventional Internet applications like remote login, electronic mail and file transfer. Nevertheless, the real-time applications like video telephony or virtual conferencing require special QoS. As a result, the Internet Engineering Task Force (IETF) has proposed three main architectures to support QoS namely; IntServ, Diffserv and MPLS. However these approaches were initially designed without mobility in-mind. This paper aims to propose an efficient approach to enhance QoS in the mobile IPv6 networks. Our proposed approach was evaluated and benchmarked with the standard MIPv6 proposed by IETF. The result exhibits the proposed protocol reduced the signaling cost when it is compared with the standard protocol MIPv6.