Hamada Alshaer

An overview of network virtualization and cloud network as a service

SUMMARY Cloud computing services delivery and consumption model is based on communication infrastructure (network). The network serves as a linkage between the end-users consuming cloud services and the providers of data centers providing the cloud services. In addition, in large-scale cloud data centers, tens of thousands of compute and storage nodes are connected by a data center network to deliver a single-purpose cloud service. To this end, some questions could be raised, such as the following: How do network architectures affect cloud computing? How will network architecture evolve to support better cloud computing and cloud-based service delivery? What is the networks role in reliability, performance, scalability, and security of cloud computing? Should the network be a dumb transport pipe or an intelligent stack that is cloud workload aware? This paper focuses on the networking aspect in cloud computing and shall provide insights to these questions. Researchers can use this paper to accelerate their research on devising mechanisms for the following: (i) provisioning cloud network as a service and (ii) engineering network of data centers. Copyright

Multilayer Dynamic Traffic Grooming with Constrained Differentiated Resilience in IP/MPLS-over-WDM Networks

Our research study in this paper focuses on supporting differentiated resilience services in IP/MPLS-over-WDM networks with minimum resources while guaranteeing the quality in provisioned services (QoS) for subscribers. This has been achieved through our multilayer scheme which supports dynamic traffic grooming associated with constrained differentiated resilience. This scheme incorporates an intelligent adaptive heuristic approach and other traffic management mechanisms which solve multiple challenging problems: Differentiated multilayer dynamic traffic grooming based on connections granularity and priority, and connection admission control and wavelength assignment subject to multiple QoS and resilience constraints. We have implemented this scheme to evaluate its performance through conducting simulation experiments. The results demonstrate that our multilayer scheme can enable a network operator to significantly improve the utilization of resources in WDM networks as well as reduce the connection and bandwidth blocking probabilities of all supported traffic classes while guaranteeing their requirements in terms of QoS, resilience and optical physical impairments.

A framework for resource dimensioning in GPON access networks

In gigabit passive optical networks (GPONs), the ports of the optical line terminal (OLT) support passive optical networks (PONs). An optical split ratio supported on an OLT chassis determines the number of optical network units (ONUs) which can share PON link capacity. Generally, network planners tend to do dimensioning for PON link capacity (OLT port) based on the number of subscribers and their type (i.e. residential or business). Although this dimensioning approach is simple, it does not guarantee a selection of optical split ratio which can optimally allocate bandwidth to end-subscribers. In this paper, we develop an integrated mathematical framework for optimally dimensioning resources in an GPON access network, namely OLT capacity. This framework comprises three resource-dimensioning approaches which are based on user requirements: GPON link utilization and capacity optimization. Our mathematical framework has been integrated into software for GPON resource dimensioning, which we have developed to evaluate the support and performance of services in GPON access networks. Copyright

An integrated architecture for multi-homed vehicle-to-infrastructure communications

We develop an intelligent distributed quality-of-service (QoS) control scheme which inter-operates between mobile routers, managing vehicular networks mobility, and road communication gateways (RCGs). This scheme manages vehicle-to-infrastructure (V2I) communications by enabling multi-homed vehicular networks to evenly distribute traffic among egress links of their mobile routers based on vehicular communication policies, available bandwidth and performance metrics of selected routing paths with correspondent nodes (CNs). In this scheme, the data control plane is considered as a collaborative entity and specifies detailed operations to be performed in the mobile routers and RCGs. Simulation experiments show that our proposed scheme can improve the congestion window (CWND) of TCP and the e2e packet loss of video traffic, despite network mobility. It also guarantees the service parameter settings of each uplink and downlink connection, while achieving reasonable utilization efficiency of network resources.

An end-to-end QoS scheme for GPON access networks

This paper introduces an end-to-end QoS scheme for GPON access networks, which consists of an intra-ONU dynamic weighted fair queuing (DWFQ) scheduler and a multiservice dynamic bandwidth allocation algorithm(MDBA). Both DWFQ and MDBA are integrated in DWFQ-MDBA scheme to support proportional differentiated services (PDiff-Serv) while alleviating the problem of light-loaded penalty resulting from intra-ONU strict priority scheduling employed in GPON access networks. We conduct detailed simulation experiments using our developed Java-based simulator to study the performance and validate the effectiveness of the proposed DWFQ-MDBA scheme in terms of the average packet delay and utilization.

Planning rules for split ratio selection in building GPON-based access networks

A dimensioning process of Gigabit Passive Optical Network (GPON) involves the selection of a split ratio that determines the allocated bandwidth per subscriber sharing a single passive optical network (PON) link (Optical Line Terminal (OLT) port). The selection of a small split ratio can be costly, whereas the selection of a higher split ratio can reduce the bandwidth allocated per subscriber and subsequently subscribers may quickly experience less quality in provisioned services. This paper aims to introduce planning rules and a mathematical model which can enable network planners, from day one, to optimally dimensioning GPON access network resources (PON link capacity, OLTs ports, splitters ports). The mathematical model considers four parameters for optimal dimensioning GPON access network: Number of subscribers and their type, busy hour, service penetration rate and bandwidth requirement. The planning rules and mathematical model have been integrated into a software utility which we have developed to evaluate the support of next-generation services in GPON access network.

A QoS architecture for provisioning high quality in intelligent transportation services

A multi-homed vehicular mobile network uses different wireless and radio communication technologies to reach the Internet through multiple routing paths. Because of network mobility and lack of reliable quality-of-service (QoS) support in these communicating technologies, it is challenging to guarantee high quality in vehicle-to-infrastructure (V2I) communications. In this paper, we evaluate a novel policy to support resource reservation for mobile networks. We also define a probing mechanism based on IPv6 messages and traffic load estimation at mobile routers and home agent to enable NEMOs choose the most optimal egress routing path to reach Internet. Intelligent transportation service providers (ITSPs) can deploy this proposed QoS architecture to realize Service Level Agreements (SLAs) based on QoS negotiation with NEMOs or quality in provisioned multimedia services for on-board users.

Securing vehicular ad-hoc networks connectivity with roadside units support

This paper evaluates three inter-vehicle spacing models based on exponential, Generalized Extreme Value, and Exponential with robustness factor statistical distributions [1], [2], [3]. Vehicles adjust transmission range as a function of its spatial density on a road segment to increase its network connectivity with other vehicles. This connectivity can be secured by deploying this scheme [4] which secures communications among vehicles through trusted road-side units that distribute secret keys to vehicles under their coverage.

An Overview of Maritime Wireless Mesh Communication Technologies and Protocols

Maritime wireless mesh networks (MWMNs) are conceived to provide network connectivity for maritime users and enable them to communicate with correspondent users connected to terrestrial communication networks. The high cost and low data-rate of satellite and other legacy maritime communication technologies and systems deployed in MWMNs pose major limitation to establish reliable and affordable maritime communications. In addition, the design of routing protocols in MWMNs remains a significant challenge due to the lack of reliable communication infrastructure and complexity of maritime environment. This paper explains the existing maritime communication technologies and routing protocols which could be deployed in implementing reliable MWMNs. Comprehensive guidelines are outlined to easily understand and critically assess the different deployed maritime communication networks and systems with routing protocols, and identify the milestones in the process of developing and implementing broadband MWMNs.

Fair resource allocation and control in multi-operator GPON access networks

Service providers and users are located at the opposite ends of the Gigabit passive optical access network (GPON) channel [1] and hence fair resource allocation and control for both service providers and users can be very challenging. This paper introduces an integrated scheme for optimizing resource allocation in multi-operator GPON access networks.