Tri M. Nguyen

Software defined service migration through legacy service integration into 4G networks and future evolutions

With the ongoing worldwide deployment of 4G networks and consequent drop of the utilization ratio of legacy networks, network operators need a cost-effective way to flexibly operate and manage networks. The obligatory continuation of legacy services in their respective legacy networks consistently incurs OPEX. In this situation, we argue that network operators can benefit from the recent advances in SDN and NFV. This article introduces a blueprint for designing a novel network architecture that integrates legacy network services into 4G networks through SDN/NFVs software-based characteristics. In addition, our architecture reduces time to market for employing newly emerging services without mandating any changes in 4G infrastructures.

Mobile flow-aware networks for mobility and QoS support in the IP-based wireless networks

Abstract As the volume of mobile traffic consisting of video, voice, and data is rapidly expanding, a challenge remains with the mobile transport network, which must deliver data traffic to mobile devices without degrading the service quality. Since every Internet service holds its own service quality requirements, the flow-aware traffic management in fine granularity has been widely investigated to guarantee Quality of Service (QoS) in the IP networks. However, the mobile flow-aware management has not been sufficiently developed yet because of the inherent constraints of flow routing in the mobile networks regarding flow-aware mobility and QoS support. In this paper, we propose a flow-aware mobility and QoS support scheme called mobile flow-aware network (MFAN) for IP-based wireless mobile networks. The proposed scheme consists of dynamic handoff mechanisms based on QoS requirements per flow to reduce the processing overhead of the flow router while ensuring QoS guarantee to mobile flows. The performance analyses of the proposed scheme demonstrate that MFAN successfully supports the mobile flow traffic delivery while satisfying the QoS requirement of flows in the wireless mobile IP networks.

A load distribution scheme over multiple controllers for scalable SDN

In this paper, we propose a load distribution scheme on a per-flow basis over multiple controllers in SDN (Software-Defined Networking). Specifically, when the capacity of a controller reaches a threshold, the controller makes incoming messages be migrated to other controllers to prevent them from being blocked. Analytical results show that our scheme has lower blocking probability and higher controller capacity utilization ratio than the conventional scheme.

QoS-aware dynamic resource allocation for wireless broadband access networks

The development of the advanced wireless access technologies is focusing on the enhancement of mobile user satisfaction in terms of quality of service (QoS). As the number of mobile users increases, the amount of traffic passing through base station (BS) significantly increases so that the preplanned capacity of downlink or uplink can be exceeded from time to time resulting in the degradation of users’ QoS satisfaction. A way to utilize the downlink (DL) and the uplink (UL) of an orthogonal frequency division multiple access frame efficiently is therefore needed subject to users’ bandwidth demand which changes continuously over the time. In this paper, we propose a QoS-aware dynamic resource allocation (QDRA) scheme which dynamically adjusts the DL/UL ratio to allocate bandwidth for QoS support to users based on the usage statistics. The performance of the proposed QDRA scheme was examined by applying to the WiMAX standard specifications, to show its superiority of maintaining a higher QoS support for various classes of services compared to the pre-reported adaptive method.

A provisioning scheme for guaranteeing recovery time in WDM mesh networks

This paper proposes a new provisioning scheme of the WDM networks to guarantee the recovery time defined in service level agreement (SLA). In our proposed scheme, the fault management scheme and working path or a pair of paths are selected based on the comparison of the pre-calculated recovery time with the recovery time required by the customer in resource efficient manner. Simulation results show that the proposed scheme outperforms the conventional schemes such as dedicated and shared path protection in terms of recovery time satisfaction ratio and resource utilization ratio.

A mobility-aware flow admission control scheme in OpenFlow-based mobile networks

This paper proposes a mobility-aware flow admission control scheme in OpenFlow based mobile networks. Proposed scheme performs classification of the input messages at the control plane considering mobility and types of services. Then, different amount of capacities are allocated according to the class for prioritized admission control. Proposed scheme is evaluated in terms of blocking probability and average waiting time in the control plane. The analytical results demonstrate that proposed scheme has both lower blocking probability and average waiting time for high prioritized messages.

Dynamic downlink and uplink subframe boundary adjustment for capacity improvement and QoS support in mobile WiMAX

Mobile WiMAX is a promising broadband access technology providing wireless last mile connectivity. In the Time Division Duplex (TDD) mode, a WiMAX frame is divided into two parts: downlink and uplink subframes. The subframe division ratio is normally set to a fixed value, resulting in under-utilization of the downlink or uplink subframes. In this paper, we propose a dynamic downlink and uplink subframe boundary adjustment scheme in which the downlink and uplink subframe ratio is dynamically adjusted upon the usage statistics. It consequently improves the frame utilization efficiency, system capacity as well as QoS support.

Mobile flow-aware management for mobility and QoS support in mobile networks

Mobility is the most important feature of a mobile communication system. Moreover, as the volume of mobile traffic consisting of video, voice, and data is rapidly expanding, the challenge rests with the mobile transport network which must deliver the data traffic to mobile devices without degrading the service quality. In this paper we proposed a flow-aware QoS and mobility management scheme for IP-based mobile wireless network. The proposed scheme consists of dynamic handoff mechanisms based on QoS requirements per flow, which is to reduce the processing overhead of the flow router while ensuring QoS guarantee to mobile flows. The performance analyses demonstrated that the proposed scheme successfully supports the mobile flow traffic delivery satisfying the QoS requirement of flows in the wireless mobile IP networks.

QoS Provisioning Based on Flow-State Routing for Proxy Mobile IP

In the next-generation mobile wireless networks, mobility support and QoS provisioning are two critical issues. When it becomes much easier to access the internet from mobile devices, the real-time service over mobile network will be on high demand. To satisfy these requirements we must consider finest level of QoS guarantee in the mobile network. In this paper, we propose a QoS Provisioning Method based on flow-state routing for Proxy Mobile IP. We present the network-based mobility support and QoS provisioning.